Dodge · Engine · Critical code

P0300 on Dodge: How to Diagnose & Fix

Random/Multiple Cylinder Misfire Detected

15 Dodge models · 27 documented issues · 16 critical · $40-$15,000 repair

P0300 on Dodge by model: symptoms, diagnosis and fix

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HEMI engines with Multi-Displacement System (MDS) can develop a ticking noise from the MDS lifters. This is most noticeable at idle and during light acceleration. While often not immediately harmful, it can indicate lifter wear.

Common Symptoms

Ticking noise at idle
Tick that follows engine RPM
Noise louder when warm
Tick comes and goes
Sound from top of engine

How to Fix

Use quality synthetic oil meeting Chrysler MS-6395 spec. MDS delete kit available for permanent solution. Some owners have had lifters replaced under extended warranty. Regular oil changes help minimize tick.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Mopar 53022263AF 5.7L HEMI MDS/VVT camshaft
Replace only when inspection shows lifter-related lobe damage Fitment: Verified 5.7L branch; not the 6.4L camshaft Live OEM direct product page when checked
Mopar Parts Giant

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Typical repair cost:$0 - $3,000

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High ConfidenceVerified1,400 owner reportsLast reported by owners Jun 2023Reviewed Aug 2026

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HEMI engines with Multi-Displacement System (MDS) can develop a ticking noise from the MDS lifters. This tick is most noticeable at idle and during light acceleration. While often not causing immediate damage, it can indicate lifter wear that may eventually require attention.

Common Symptoms

Ticking noise at idle
Tick that follows engine RPM
Noise louder when engine is warm
Tick comes and goes
Noise from top of engine

How to Fix

Use quality synthetic oil meeting Chrysler MS-6395 spec. Consider MDS delete kit if desired permanent solution. Some owners have had lifters replaced under extended warranty. Regular oil changes help minimize tick.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Genuine Mopar 53022298AB Multiple Displacement Solenoid
Replace only when testing shows the solenoid/control branch is faulty rather than a collapsed lifter or worn cam Fitment: 2010-2024 5.7L/6.4L MDS applications per live title; confirm the vehicle actually has MDS Live direct US performanc…

Typical repair cost:$0 - $3,000

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High ConfidenceVerified1,100 owner reportsLast reported by owners Feb 2024Reviewed Aug 2026

Community reported

850 owners

The 3.6L Pentastar V6 can develop a ticking noise often related to the rocker arms or hydraulic lifters. This is common on engines with higher mileage or irregular oil change intervals. Some early Pentastar engines had rocker arm design issues that were later updated.

Common Symptoms

Ticking noise at startup
Tick that varies with RPM
Noise from valve cover area
Check engine light with misfire codes
Rough idle in severe cases

How to Fix

Use quality synthetic oil and change regularly. If tick is severe, rocker arms may need replacement with updated design. Some owners have had success with engine flush treatments. Check for TSBs related to your model year.

Typical repair cost:$100 - $1,500

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High Confidence850 owner reportsLast reported by owners Feb 2024Reviewed Feb 2026

All Dodge Charger known issues →

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Some 2015-2021 Dodge Challenger 5.7L and 6.4L engines can develop a persistent engine-speed-related tick, rough idle, loss of power, or misfire from hydraulic roller-lifter, roller, or cam-lobe wear. A tick alone does not prove internal wear: exhaust-manifold leakage, injector noise, oil-pressure concerns, and other causes must be ruled out. MDS fitment is transmission-specific, not engine-name-wide: automatic 5.7L and 6.4L applications use cylinder deactivation, while six-speed manual applications are non-MDS. Cam and lifter wear is not limited to MDS hardware.

Common Symptoms

Ticking noise at idle
Tick goes away when engine warms up
Tick more prominent on cold start
Noise from top of engine

How to Fix

Retrieve DTC and misfire data, localize the noise, and check for exhaust-manifold leakage before buying internal parts. If cam/lifter wear is suspected, inspect the lifter rollers and cam lobes and check the VVT oil-control-valve screen for metal debris. FCA STAR case S1709000010 directs camshaft/lifter replacement when wear is confirmed and no screen debris is present; debris can indicate that a larger repair or engine replacement is required. Use the lifter type that matches the factory transmission/MDS configuration and verify by VIN. A stock automatic-MDS full-engine service set requires two front 5038785AD packs and two rear 5038786AD packs. A factory non-MDS/manual full-engine set requires four OEM 5038784AD packs, or an exact retailer bundle of sixteen lifters and four yokes. On an automatic-MDS car, non-MDS lifters are only one part of a complete engineered mechanical delete with compatible cam/supporting parts and calibration. Correct oil and electronic MDS disabling do not repair a worn lifter, roller, or camshaft.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Genuine Mopar 5038785AD front MDS hydraulic lifters and yoke pack
Front-position MDS lifter pack for a confirmed MDS valvetrain repair after the heads are removed and roller/cam damage is inspected Fitment: Live fitment lists 2009-2023 Challenger 5.7L/6.4L, but the year-specific catalog specifies MDS/f…
Mopar Parts Giant
Genuine Mopar 5038786AD rear MDS hydraulic lifters and yoke pack
Rear-position companion pack for a complete factory-MDS lifter repair Fitment: Live fitment lists 2009-2023 Challenger 5.7L/6.4L; pair with the front packs only on a verified MDS engine, and confirm that two front plus two rear packages …
Mopar Parts Giant
Genuine Mopar 5038784AD complete non-MDS HEMI lifter/yoke bundle
Complete lifter branch for a factory non-MDS/manual-transmission 5.7L or 6.4L after cam and roller inspection confirms replacement Fitment: Live bundle explicitly contains 16 lifters and four yokes and lists 2015-2023 Challenger 5.7L/6.4…
teamhellcat
Genuine Mopar 53022372AA 5.7L MDS/VVT camshaft
Camshaft replacement when lifter-roller failure has visibly or measurably damaged a lobe on the verified 5.7L MDS engine Fitment: Year-specific catalogs identify this as the 5.7L MDS cam; direct fitment lists 2009-2023 Challenger 5.7L. D…
Mopar Parts Giant

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Typical repair cost:$100 - $2,500

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High ConfidenceVerified678 owner reportsLast reported by owners Jan 2024Reviewed Aug 2026

Community reported

345 owners

The 3.6L Pentastar V6 engine can develop a ticking noise from worn rocker arms. Unlike the HEMI MDS tick, this is caused by the roller follower rocker arms wearing out prematurely. The issue typically appears between 50,000-100,000 miles and is more common on 2011-2013 engines but can occur on later models.

Common Symptoms

Ticking noise from engine at idle
Tick may worsen when engine is warm
Check engine light for misfire codes
Rough idle in severe cases
Ticking noise changes with RPM

How to Fix

Replace the affected rocker arms. Many owners replace all 24 rocker arms preventatively when doing this repair ($400-800 for parts). Labor is 4-6 hours ($400-600). Total repair cost is typically $800-1,400. Using quality synthetic oil and regular oil changes can help prevent premature wear.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Mopar 5184296AH valve rocker arm
Replacement for each rocker whose roller, bearing or contact surface is confirmed faulty after the valve cover is removed and the cam lobes are inspected Fitment: Live OEM fitment lists 2011-2023 Challenger 3.6L and the year catalog requ…
Mopar Parts Giant

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Typical repair cost:$800 - $1,400

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High ConfidenceVerified345 owner reportsLast reported by owners Feb 2024Reviewed Aug 2026

A P0300 "random/multiple cylinder misfire" code with a rough, shaking idle is one of the most common drivability complaints on the Dodge Challenger, and on a high-mileage or maintenance-overdue car it is most often caused by worn spark plugs and/or weak ignition coils rather than an internal engine fault. The 5.7L and 6.4L HEMI V8s are especially prone because they run two spark plugs per cylinder (16 total), so worn plugs are a frequent misfire source; the 3.6L Pentastar V6 also commonly throws misfires from failing coil-on-plug units. Because P0300 is the "random/multiple" code (versus cylinder-specific P0301–P0308), it points to a condition affecting several cylinders at once — typically a full set of tired plugs, or coils that break down intermittently under load/heat. Owners notice it most at idle and during light acceleration. Critical: if the check engine light is FLASHING, the misfire is severe enough to dump raw fuel into the exhaust, which can quickly overheat and destroy the catalytic converter(s) — turning a routine tune-up into a far more expensive repair. Note: the 2011–2013 3.6L V6 also had a documented left-cylinder-head defect (Chrysler warranty extension X56), and 2014+ Pentastars can suffer rocker-arm needle-bearing wear; these can present similar misfire codes and should be ruled out if new plugs and coils don't resolve the P0300.

Common Symptoms

Check engine light with code P0300 (random/multiple cylinder misfire)
Rough, shaking, or unstable idle
Hesitation or stumble under light acceleration
Reduced power and engine surging
Flashing check engine light during a severe misfire (warns of catalytic converter damage)
Slightly rough running or vibration felt through the cabin
Occasional rotten-egg/sulfur smell or fuel smell if cat is being damaged

How to Fix

Start with a full ignition tune-up before chasing internal-engine causes. Pull and inspect the spark plugs for wear, fouling, or excessive gap; replace the complete set with the correct factory-spec iridium plugs (HEMI V8s take 16 plugs — both banks must be done). To pinpoint a bad coil, swap the coil from a suspect cylinder to an adjacent easy-access one, clear codes, and retest — if the misfire follows the coil, replace that coil (replacing all coils as a set is common on high-mileage cars). Also check for vacuum/intake leaks (smoke test) and inspect fuel injectors if plugs and coils are good. Spark plug intervals: the 5.7L HEMI called for ~30,000 miles through 2013, extended to ~100,000 miles for 2014+; long-life iridium plugs are standard. DIY parts are inexpensive (a set of HEMI plugs runs roughly $130, individual coils are modest), making this a high-value job to do yourself. If the CEL is flashing, stop driving and tow it to avoid catalytic-converter damage. If a fresh set of plugs and coils does NOT clear the P0300, move on to compression/leak-down testing to rule out the 2011–2013 head defect or rocker-arm/lifter wear.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Genuine Mopar SP149125AF spark plug
Complete six-plug tune-up branch when inspection, service interval or testing identifies worn/fouled plugs on the 3.6L Pentastar Fitment: Live exact fitment lists 2011-2023 Challenger 3.6L and supersedes SP149125AD/AE; a complete engine …
Mopar Parts Giant
Genuine Mopar SP143877AB spark plug
Later 5.7L sixteen-plug tune-up branch after confirming the model year/engine specification Fitment: Live exact fitment lists 2014-2023 Challenger 5.7L and supersedes SP143877AA/68143877AB; a complete engine set requires 16 individual pl…
Mopar Parts Giant
Genuine Mopar SP149212AC spark plug
6.4L sixteen-plug tune-up branch when plug wear/fouling is confirmed Fitment: Live exact fitment and year catalog list 2011-2023 Challenger 6.4L; a complete engine set requires 16 individual plugs $13.46 each and Add to Cart on the live …
Mopar Parts Giant
Genuine Mopar 5149168AJ ignition coil, current replacement for 5149168AI/AH
Confirm VIN and current supersession $86.63 each and Add to Cart on the live OEM supersession page when checked
Mopar Parts Giant
Genuine Mopar 68238603AA V8 ignition coil
Test-confirmed coil replacement branch for the 5.7L or 6.4L after a coil swap/circuit test identifies the failure Fitment: Live exact fitment includes 2008-2023 Challenger V8 applications and year catalogs require eight coils; the issue …
Mopar Parts Giant

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Typical repair cost:$130 - $900

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Medium ConfidenceVerifiedReviewed Aug 2026

A P0420 ("Catalyst System Efficiency Below Threshold, Bank 1") or P0430 ("Bank 2") check-engine light is one of the most common emissions codes on the Dodge Challenger, especially on higher-mileage V8 cars. The PCM sets the code when it compares the upstream (pre-cat) and downstream (post-cat) oxygen-sensor signals: if the downstream sensor begins to mimic the rapidly-switching upstream sensor instead of staying relatively flat, the computer concludes the converter is no longer storing/releasing oxygen efficiently. On the Challenger this code is frequently NOT a worn-out converter at all. The two most common upstream root causes are (1) an exhaust leak from broken exhaust-manifold bolts — the well-documented "HEMI tick" on the 5.7L and 6.4L V8s — which lets atmospheric oxygen into the exhaust stream and confuses the rear O2 sensor, and (2) a long-running misfire (worn plugs, failing coils, leaking injectors on the 3.6L Pentastar) that dumps raw fuel into the converter and physically destroys it over time. A failed downstream O2 sensor, contaminated converter (from an oil-cooler/oil-filter-housing leak on the Pentastar), or simply an aged/degraded cat round out the causes. Chrysler also issued software bulletins (TSB 18-021-12, superseded by 18-033-13) because early PCM calibration logic was overly sensitive and could trigger false P0420/P0430 codes — particularly in warm weather or on long highway drives — so a PCM reflash should be ruled out before any hardware is replaced. Because the converter sits in the federal/CARB emissions-warranty window for many of these cars, the diagnosis order matters a lot to the owner's wallet.

Common Symptoms

Check Engine Light on with stored code P0420 (Bank 1) and/or P0430 (Bank 2)
Vehicle may run normally with no obvious driveability change at first
Failed state emissions / smog inspection
Possible rotten-egg (sulfur) smell from a degrading converter
Slight loss of power or fuel economy if the converter is partially clogged
Often accompanied by a cold-start exhaust tick (broken manifold bolts) on the V8
Code returns shortly after clearing if root cause is not fixed

How to Fix

Diagnose before you spend. (1) Pull all stored codes first — if any misfire (P0300-P030x) or O2-sensor codes are also present, fix those first, since a misfire will quickly kill a new converter. (2) Inspect for exhaust leaks, especially broken exhaust-manifold bolts on the 5.7L/6.4L V8 (look for soot/ticking at the manifold flanges); repair the leak and clear the code before condemning the cat — a manifold leak is a very common false-trigger of P0420 on the HEMI. (3) Check for a PCM software update at the dealer per TSB 18-021-12 / 18-033-13, which addresses incorrectly-set P0420/P0430 codes. (4) Graph the oxygen sensors with a scan tool: the downstream (Bank 1 Sensor 2 / Bank 2 Sensor 2) signal should be slow and steady; if it copies the fast-switching upstream sensor, the converter is failed. A failing downstream O2 sensor is a much cheaper part to try than a converter. (5) Only after ruling out leaks, misfires, software and sensors should the catalytic converter be replaced. Use an OEM Mopar or quality CARB-compliant aftermarket (e.g., MagnaFlow) unit; cheap universal cats often re-trigger the code. On the 3.6L Pentastar, also confirm the oil-filter-housing/oil-cooler is not leaking oil into the system, as that contamination will destroy a new converter. Note: the converter is covered under the federal 8-year/80,000-mile emissions warranty (and 15-year/150,000-mile in California) on many of these model years — check before paying out of pocket.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

OBDLink MX+ Bluetooth OBD-II adapter with included apps
Graph upstream and downstream oxygen-sensor behavior and fuel-trim data after misfires and exhaust leaks are repaired, before condemning a converter Fitment: Generic OBD-II live-data tool; confirm the app exposes the required PIDs on the…
Genuine Mopar 5149180AB oxygen sensor
Sensor branch only when waveform, heater-circuit and wiring tests identify the exact failed sensor rather than converter inefficiency Fitment: Live fitment lists 2011-2023 Challenger 3.6L/5.7L/6.2L/6.4L, but catalog position varies by ye…
Mopar Parts Giant
MagnaFlow 16420 OEM-grade federal/EPA direct-fit catalytic converter assembly
Confirm engine family and local emissions rules $911.90 with Add to Cart on the live US retailer page when checked
Genuine Mopar 6509863AA exhaust-manifold stud
Repair an identified 5.7L manifold fastener leak before evaluating converter efficiency again Fitment: 2009-2020 Challenger 5.7L side-position stud, sold individually; other engines and positions require their own hardware $11.65 and Add…
Mopar Parts Giant
Fel-Pro MS97083 exhaust-manifold gasket set
Reseal a confirmed 5.7L manifold-to-head leak before interpreting catalyst-monitor data Fitment: 5.7L HEMI branch only after vehicle fitment confirmation; not the 6.1L/6.2L/6.4L gasket $56.99 and Add to Cart on the live AutoZone US produ…
AutoZone

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Typical repair cost:$40 - $2,379

Sources for this issue (1)

FCA TSB 18-090-24 - 2019 Challenger PCM Updatestsb

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Medium ConfidenceVerifiedReviewed Aug 2026

The production valve springs on the 6.4L 392 HEMI can crack or fracture. A weakened spring can cause a persistent single-cylinder misfire that remains after plug, coil, or injector swaps; a complete fracture can let the valve contact the piston and cause major cylinder-head or engine damage. High-RPM and modified/cammed use changes valvetrain load, but the correct replacement spring must be selected from the camshaft's lift and required installed/open pressures rather than from boost alone.

Common Symptoms

Persistent single-cylinder misfire that does NOT go away after replacing spark plugs, coil packs, or injectors
Rough idle, stuttering, and a shaking/vibrating engine
Check engine light flashing under load (active misfire)
Loss of power and the car going into limp/reduced-power mode
Low compression on the affected cylinder during a compression or leak-down test
Ticking, clattering, or valvetrain noise from one bank
In a full failure: severe knocking, loss of a cylinder, then catastrophic engine failure (dropped valve)
Symptoms most often appear after track use, hard high-RPM driving, or on modified/cammed/boosted cars

How to Fix

Stop driving if a broken spring is suspected. Confirm the fault with compression or leak-down testing and valve-cover inspection before buying parts. For affected 2021-2022 Challenger/Charger 6.4L vehicles, FCA GPOP bulletin 9004444 directs technicians to replace all valve springs after a broken spring is confirmed, not only the failed spring; other model years should follow the current VIN-specific service procedure. The OEM production repair uses sixteen 5037382BC springs. Mopar Performance 68277306AA is an individual higher-lift spring: a full 6.4L engine requires sixteen plus correctly sized shims, and the spring must match the camshaft's lift and pressure requirements. Aftermarket PAC/BTR/Comp/Livernois sets should likewise be selected to the cam manufacturer's specification.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

High Horse Performance bundle of 16 genuine Mopar 5037382BC production valve springs
Full-engine production-spring repair after compression/leak-down and valve-cover inspection confirms a broken or weakened spring Fitment: 2011-2023 Challenger 6.4L 392 HEMI subset in this issue; the live title extends through 2024 and ex…
Mopar Performance 68277306AA beehive valve spring
Modified/cammed engine branch only when the camshaft manufacturer specifies this spring's lift and pressure characteristics Fitment: One spring; sixteen plus correctly sized shims are required for a full 6.4L engine, and this must not be…
Mopar Parts Giant
OTC 5609 cylinder leakage tester kit
Confirmation tool before buying valve-spring parts; distinguishes valve leakage from rings, cylinder walls or head-gasket leakage Fitment: Universal professional test tool with 14 mm hose and 10/12/18 mm adapters; requires a regulated co…
AutoZone

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Typical repair cost:$700 - $5,000

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Medium ConfidenceVerifiedReviewed Aug 2026

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The 5.9L Magnum V8 intake manifold plenum gasket is a well-known failure point. The factory gasket degrades and allows engine oil to be drawn into the intake, causing oil consumption, misfires, and loss of power. The plenum pan sits atop the intake manifold and the gasket between them deteriorates over time. This is considered an inherent design flaw in all Magnum V8 engines (5.2L and 5.9L). Hughes Engines offers a permanent fix with a billet aluminum plenum plate that eliminates the gasket entirely.

Common Symptoms

Excessive oil consumption
Engine misfires and rough idle
Oily residue visible through throttle body
Loss of power under load
Engine pinging or knocking

How to Fix

Confirm plenum gasket failure by removing the air hat and throttle body and checking for pooled oil or heavy oily residue in the intake, then verify with a vacuum test if needed. Repair requires removing the intake manifold, replacing the failed plenum pan gasket with an upgraded kit or, preferably, installing a Hughes Engines billet aluminum plenum plate and revised gasket set, along with new intake manifold belly pan bolts and threadlocker. While apart, inspect the manifold for warping and replace related intake gaskets, coolant, and vacuum lines as needed before torquing everything to spec in sequence. Typical repair cost is about $400-$900 in parts and labor at an independent shop, or roughly $150-$350 in parts for a DIY repair depending on whether the billet upgrade is used.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Billet plenum plate, Fel-Pro intake/plenum gaskets, bolts and bypass hose
Repair a confirmed Magnum V8 belly-pan/plenum leak Fitment: Hughes states all 1992-2003 Dodge/Jeep 5.2L and 5.9L Magnum V8 engines Live direct manufacturer product page when checked

Typical repair cost:$150 - $500

Sources for this issue (1)

DaimlerChrysler TSB 09-05-00 - Spark Knock and Oil Consumption Due to Intake Manifold Pan Gasket Oil Leaktsb

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The same notorious 2.7L DOHC V6 sludge issue that plagues the Intrepid affects the 2nd generation Stratus. Inadequate oil drain-back passages in the cylinder heads allow oil to cook and form thick sludge deposits that clog passages and starve bearings of oil. The water pump is chain-driven inside the engine and when it leaks, coolant mixes with oil, dramatically accelerating sludge formation. Engine seizure often occurs between 60,000-100,000 miles. This engine earned a reputation as one of the worst ever produced by Chrysler.

Common Symptoms

Oil pressure warning light illuminating
Engine knocking or tapping sounds
Heavy sludge visible on oil filler cap
Overheating due to sludge-clogged passages
Complete engine seizure

How to Fix

Confirm the problem by checking oil pressure with a mechanical gauge, inspecting under the oil filler cap/valve covers for sludge, cutting open the oil filter, and pressure-testing the cooling system to check for an internal water pump leak contaminating the oil. Mild cases may sometimes be addressed with repeated short-interval oil and filter changes after removing the valve covers and oil pan to manually clean sludge and replace the oil pickup tube/screen, but most engines with knocking, low oil pressure, or coolant in the oil require full engine replacement or complete teardown/rebuild with updated timing components, internal water pump, oil pump, bearings, and thorough passage cleaning. Also replace the PCV valve, thermostat, and any compromised cooling components, then use the correct oil and strict 3,000-4,000 mile service intervals to prevent recurrence. Typical cost is about $800-$1,800 for limited cleaning/repair if caught early, but $3,500-$6,500+ for a quality rebuild or replacement engine installation.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Cloyes primary/secondary timing-chain, guide and tensioner kit
Timing-system branch when internal water-pump service or inspection requires chain-system replacement Fitment: 2001-2006 Stratus 2.7L sedan; sprockets and water pump are not included in this exact kit Live in-stock direct US product page…
PartsGeek

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Typical repair cost:$2,500 - $5,000

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High ConfidenceVerified400 owner reportsLast reported by owners Feb 2026Reviewed Aug 2026

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The 2.4L DOHC 4-cylinder engine (used across both Stratus generations) is prone to head gasket failure, particularly when overheating occurs. The aluminum cylinder head warps more easily than cast iron, and once warped, the head gasket cannot maintain a proper seal. Coolant mixing with oil or exhaust gases entering the cooling system are the primary failure modes. While more reliable than the 2.7L V6, the 2.4L still requires careful cooling system maintenance. The factory composite head gasket has been superseded by improved MLS (multi-layer steel) designs.

Common Symptoms

White smoke from exhaust (coolant burning)
Coolant loss with no visible external leak
Engine overheating
Milky residue on oil dipstick or filler cap
Bubbling in coolant overflow reservoir

How to Fix

Confirm head gasket failure with a cooling-system pressure test, combustion-gas/block test, and compression or leak-down test, then inspect for coolant in the oil and check the cylinder head and block deck for warpage after disassembly. Repair requires removing the cylinder head, machining or replacing the head if out of spec, and installing an updated MLS head gasket with new torque-to-yield head bolts; the timing belt, water pump, thermostat, and radiator cap should also be inspected or replaced if overdue to prevent repeat overheating. Flush contaminated oil and coolant, refill with the correct fluids, and verify radiator fan operation and overall cooling-system condition before returning the car to service. Typical repair cost is about $1,200-$2,500 depending on machine-shop work, related cooling-system parts, and whether the head must be replaced.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Fel-Pro HS9924PT-1 cylinder-head gasket set
Early 2.4L head-gasket repair after testing and machine-shop inspection Fitment: Live page verifies 2001 2.4L and catalog evidence covers early applications; select exact year/valve-cover/body configuration rather than extrapolating to 2…
PartsGeek
Fel-Pro HS26202PT-1 cylinder-head gasket set
Later 2.4L head-gasket repair where the nine-bolt valve-cover configuration matches Fitment: 2004-2006 2.4L with specified valve-cover configuration; not the full 1995-2006 range Live direct US product page with price and availability wh…
PartsGeek
Fel-Pro ES71028 torque-to-yield head bolts with washers
Required new fasteners for the head-gasket repair Fitment: Live fitment lists 1995-2006 Stratus 2.4L; use the exact service-manual torque-angle procedure Live in-stock direct US product page when checked
PartsGeek

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Typical repair cost:$600 - $1,500

Sources for this issue (1)

DaimlerChrysler TSB 09-08-99 - Multi-Layer Steel Head Gasket Installation Procedurestsb

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High ConfidenceVerified280 owner reportsLast reported by owners Feb 2026Reviewed Aug 2026

All Dodge Stratus known issues →

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The 3.3L and 3.8L V6 engines suffer from water pump failures, thermostat sticking, and radiator fan relay failures. Overheating can cause head gasket failure. Fan relay is the most common single failure point. Same cooling system as Chrysler Town & Country.

Common Symptoms

Engine overheating, especially at idle or in traffic
Coolant leak from water pump area
Temperature gauge fluctuating
Heater blowing cold air
Radiator fan not running at idle

How to Fix

Replace water pump (Gates 43090 for 3.8L), thermostat (Stant 45359, 195F), and radiator cap as a set. Check fan relay (5149541AA) and fan module (5017407AB). Use Mopar OAT coolant (68048953AB) only.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Gates 42292 engine water pump
Replace a leaking or noisy pump for the early issue subset Fitment: 2001-2007 Grand Caravan 3.3L/3.8L verified application Live direct US product page when checked
partcatalog
Gates 41202 engine water pump
Later-generation water-pump replacement Fitment: 2008-2010 Grand Caravan 3.3L/3.8L Live direct US product page when checked
Mopar five-year/100,000-mile HOAT coolant concentrate
Refill with the correct HOAT chemistry after cooling-system repair Fitment: MS-9769 HOAT for this 2001-2010 issue; never mix with later Chrysler OAT chemistry Live OEM direct product page when checked
Mopar Parts Giant
Mopar 4596198 radiator/recovery-tank cap
Replace a cap that fails pressure testing during later-generation service Fitment: Verified 2008-2010 Grand Caravan branch; earlier years require exact cap lookup $26.80 and Add to cart when checked

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Typical repair cost:$400 - $1,200

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NHTSA Manufacturer Communications Data Corpusnhtsa

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High ConfidenceVerified300 owner reportsLast reported by owners Aug 2024Reviewed Aug 2026

The 3.6L Pentastar V6 in later Grand Caravans develops oil sludge and varnish buildup, particularly when oil changes are not performed at 5,000-mile intervals or when conventional oil is used. Sludge clogs the oil passages feeding the variable valve timing (VVT) system, causing camshaft actuator codes and rough running. The Pentastar is sensitive to oil quality and change intervals due to its VVT system and tight oil passages.

Common Symptoms

Check engine light with VVT solenoid or cam actuator codes
Engine ticking or tapping noise on cold start
Rough idle that smooths out once warmed up
Reduced fuel economy
Dark sludgy deposits visible on oil cap or dipstick

How to Fix

Switch to full synthetic 5W-20 oil (Pennzoil Platinum or Mobil 1 recommended) and change every 5,000 miles. For existing sludge, perform two consecutive oil changes at 1,000-mile intervals using a quality synthetic to flush deposits. In severe cases, an engine flush product like Liqui Moly Pro-Line Engine Flush can help, but use with caution on high-mileage engines. Replace VVT solenoids if cam actuator codes persist after oil change.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Mobil 1 full-synthetic SAE 5W-20 engine oil
Short-interval oil-and-filter service branch after checking mechanical oil pressure and sludge severity Fitment: Use only when the exact model-year owner's manual specifies 5W-20 and the current product meets its required API/Chrysler sp…
Amazon
Mopar 5184150AF VVT oil-control valve
Replace only if cam-actuator diagnosis persists after verified oil pressure, clean oil and circuit testing Fitment: Applicable 3.6L Pentastar subset; confirm bank/position and VIN Live Mopar direct product page when checked

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Typical repair cost:$50 - $800

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NHTSA Manufacturer Communications Data Corpusnhtsa

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Medium ConfidenceVerifiedReviewed Aug 2026

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300 owners

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275 owners

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180 owners

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220 owners

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200 owners

The 2.2L and 2.5L Chrysler K-car engines in the Shadow are prone to head gasket failure, especially after overheating episodes. The cast iron block and aluminum head expand at different rates, causing the head gasket to lose its seal over time. The 2.5L is more prone than the 2.2L due to higher combustion pressures. Coolant leaking externally at the rear of the head or internally causing white exhaust smoke are the primary symptoms. The turbo 2.2L variants are particularly susceptible due to higher cylinder pressures. These engines use a composite head gasket that has been superseded by improved designs.

Common Symptoms

White smoke from exhaust
Coolant leaking externally from back of cylinder head
Engine overheating
Coolant loss with no visible external leak
Milky oil or coolant contamination

How to Fix

Confirm head gasket failure with a cooling system pressure test, combustion gas/block test, compression test, and by checking for coolant in the oil or white exhaust smoke. Repair requires removing the cylinder head, checking it and the block deck for warpage/cracks, resurfacing the head if needed, and installing the updated head gasket set with new head bolts, along with fresh coolant and oil/filter; the timing belt, water pump, and thermostat should also be inspected or replaced while apart. If overheating caused severe damage, the head may need machine shop work or replacement. Typical repair cost is about $900-$1,800 depending on engine variant, machine work, and whether additional cooling system parts are needed.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Fel-Pro 9296 PT PermaTorque cylinder-head gasket
Primary gasket after leak-down/combustion-gas testing and machine-shop inspection confirm a repairable 2.2L/2.5L head-gasket failure Fitment: Verified 1990 Shadow 2.5L and cataloged 2.2L/2.5L applications; turbo, valve-cover design and l…
Dayco timing-belt component kit with water pump
Conditional companion service while the head is off when age, leakage, bearing condition or service history warrants replacement Fitment: 1989-1994 Shadow 2.2L/2.5L L4 only; not the 3.0L V6 Live direct US model-specific product page when…
sixityauto

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Typical repair cost:$400 - $1,000

Sources for this issue (1)

NHTSA Manufacturer Communications Data Corpusnhtsa

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High ConfidenceVerified200 owner reportsLast reported by owners Feb 2026Reviewed Aug 2026

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Community reported

180 owners

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170 owners

The Dodge Spirit shares the same 2.2L and 2.5L K-car engines as the Shadow and suffers from the identical head gasket failure pattern. The bimetallic construction (cast iron block, aluminum head) creates differential thermal expansion that breaks down the composite head gasket seal. The 2.5L is more commonly affected due to higher combustion pressures. The Spirit R/T model with the 2.2L turbo is particularly susceptible due to boost pressure stressing the gasket. Overheating from any cause (stuck thermostat, failed fan, low coolant) often triggers immediate head gasket failure on these engines.

Common Symptoms

White smoke from exhaust
External coolant leak at rear of cylinder head
Engine overheating repeatedly
Coolant disappearing with no visible external leak
Rough idle and misfires from cylinder contamination

How to Fix

Confirm head gasket failure with a cooling system pressure test, combustion gas/block test, and compression or leak-down test, then inspect for coolant seepage at the rear of the head and check for cylinder contamination. Repair requires removing the cylinder head, checking both the aluminum head and iron block deck for warpage/cracks, machining the head if needed, and installing an updated quality head gasket set with new head bolts, along with fresh coolant, thermostat, and often a water pump if overheating contributed. Carefully follow the factory torque sequence/specifications and verify radiator fan operation to prevent repeat failure. Typical repair cost is about $1,000-$1,800 depending on machine shop work and whether turbocharged R/T components or additional cooling system parts are needed.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Fel-Pro 9296 PT cylinder-head gasket
Primary gasket after cooling-system, combustion-gas and machine-shop checks confirm a repairable 2.2L/2.5L failure Fitment: Direct listing covers 1989-1995 Spirit 2.5L; 2.2L turbo/DOHC R/T and set/bolt details require separate exact-engi…
PartsGeek

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Typical repair cost:$400 - $1,000

Sources for this issue (1)

NHTSA Manufacturer Communications Data Corpusnhtsa

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Based on 170 owner reports

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High ConfidenceVerified170 owner reportsLast reported by owners Feb 2026Reviewed Aug 2026

All Dodge Spirit known issues →

Community reported

80 owners

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60 owners

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The single most documented first-generation Neon failure. The original-design head gasket weeps and then fails, most commonly at the driver's-side rear of the block where an oil passage crosses close to the block's outer edge, near the brake-fluid reservoir. Because the SOHC and DOHC share the same block, both are affected; R/T and ACR (DOHC 150 hp) cars are equally susceptible. Failures frequently appear at 40,000-70,000 miles and are aggravated by the engine's marginal cooling and the early torque-to-yield head bolts. Chrysler acknowledged it with TSB 09-05-98 (later superseded by TSB 09-08-99), releasing a redesigned multi-layer-steel (MLS) head gasket that also carried over to related 2.0L applications.

Common Symptoms

Oil seepage/leak at the head-to-block joint near the brake reservoir
Coolant loss with no obvious external leak
Overheating or fluctuating temperature
White exhaust smoke / sweet smell
Oil-coolant intermixing (milky oil) in severe cases
Rough running / misfire

How to Fix

Replace with the updated multi-layer-steel (MLS) head gasket per TSB 09-05-98/09-08-99, resurface/inspect the head for warpage, and use new head bolts (many owners upgrade to ARP studs). Address any co-existing cooling weakness at the same time. Community practice is to combine this job with the timing belt and water pump since the front of the engine is already apart.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Cometic C5497-040 87.5 mm bore MLS cylinder-head gasket
Updated gasket for the exact 420A/DOHC branch after head/block inspection Fitment: Manufacturer application lists 1995-1998 Neon 420A/ECC; not the SOHC engine or 1999 without application verification Live manufacturer direct-product page…
cometic

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Typical repair cost:$700 - $1,800

Sources for this issue (1)

DaimlerChrysler TSB 09-08-99 - Multi-Layer Steel Head Gasket Installation Procedurestsb

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High ConfidenceVerifiedReviewed Aug 2026

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The 3.9L and 5.2L Magnum engines use a two-piece intake manifold: a cast-aluminum upper and a stamped-steel plenum pan bolted to the underside with a gasket sealing them. Because the steel plate and aluminum manifold expand at different rates, over years of heat cycling the steel plate shifts and tears the gasket. Manifold vacuum then draws crankcase oil mist and blow-by up through the failed gasket into the intake runners, most notably feeding cylinder #8 on the V8. This is one of the most universally documented failures on 1992-1999 Magnum-powered Dakotas (the LA engines in 1990-1991 do not use this plenum-pan design). Chrysler issued TSBs 18-34-97, 18-48-98 and 09-05-00 addressing it.

Common Symptoms

Elevated oil consumption with no external leak
Blue smoke from tailpipe
Rough idle / cylinder miss (commonly cylinder 8)
Spark knock / pinging under acceleration
Fouled spark plugs
Lack of power

How to Fix

Replace the failed gasket and swap the original stamped-steel plenum pan for an aftermarket aluminum replacement plate that addresses the root cause. Use fresh intake bolts (the originals stretch) and reseal the manifold. A cheap fix relative to the internal wear/oil consumption it prevents. Confirm diagnosis by opening the throttle blades and shining a light into the intake for pooled oil.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

Hughes HUG 7720FEL 5.2L/5.9L Magnum V8 plenum repair kit
Complete aluminum plate, Fel-Pro gasket, fastener and bypass-hose repair Fitment: Manufacturer lists all 1992-2003 5.2L/5.9L Magnum V8 engines; this issue uses the 1992-1999 5.2L Dakota overlap $195.48 on the live manufacturer product pa…
hughesengines

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Typical repair cost:$250 - $900

Sources for this issue (1)

DaimlerChrysler TSB 09-05-00 - Spark Knock and Oil Consumptiontsb

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High ConfidenceVerifiedReviewed Aug 2026

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P0300 code reference

General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.

Frequently asked questions

What does P0300 mean on a Dodge?

P0300 stands for "Random/Multiple Cylinder Misfire Detected." P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously. On Dodge it is documented across 15 models: Durango, Charger, Challenger, Intrepid, Ram 1500, Stratus, Grand Caravan, Journey, Stealth, Shadow, Avenger, Spirit, Viper, Neon, Dakota.

What are the most common causes of P0300?

The most common causes of P0300 are: Worn or fouled spark plugs (across cylinders), Vacuum or intake air leak, Weak fuel pump, clogged fuel filter, or low fuel pressure, Failing ignition coils or worn spark plug wires, Dirty or faulty mass airflow (MAF) sensor, Clogged or dirty fuel injectors, Faulty crankshaft/camshaft position sensor, Low compression or EGR/PCV system faults. The specific cause varies by vehicle.

How much does it cost to fix P0300 on a Dodge?

Published repair estimates on Dodge range from $40 to $15,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.

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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

P0300 on Dodge by model: symptoms, diagnosis and fix

HEMI MDS Lifter Tick

Common Symptoms

How to Fix

What you need to fix it

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HEMI MDS Lifter Tick

Common Symptoms

How to Fix

What you need to fix it

Research This Issue

Pentastar V6 Rocker Arm/Lifter Tick

Common Symptoms

How to Fix

Research This Issue

HEMI Lifter/MDS Tick

Common Symptoms

How to Fix

What you need to fix it

Research This Issue

Pentastar V6 Rocker Arm/Lifter Tick

Common Symptoms

How to Fix

What you need to fix it

Research This Issue

Random Misfire / Rough Idle (P0300) From Worn Spark Plugs & Failing Ignition Coils

Common Symptoms

How to Fix

What you need to fix it

Research This Issue

Catalytic Converter Efficiency Code (P0420 / P0430)

Valve Spring Failure on 6.4L 392 HEMI (High-RPM and Modified/Boosted Cars)

2.7L V6 Engine Oil Sludge and Seizure

5.9L Magnum Plenum Gasket Failure

2.7L V6 Engine Oil Sludge Buildup and Failure

2.4L DOHC Head Gasket Failure

Cooling System Failures (3.3L/3.8L V6)

Engine Oil Sludge Buildup (3.6L Pentastar V6)

Pentastar 3.6L Rocker Arm Failure

Engine Overheating - Thermostat Housing Debris

Head Gasket Failure

3.6L Pentastar V6 Left Cylinder Head Failure (Misfire on Cylinders 2/4/6)

6G72 Timing Belt and Balancer Belt Failure

2.2L/2.5L Head Gasket Failure

2.4L Electronic Throttle Body Failure

2.2L/2.5L Head Gasket Failure

Gen 1 V10 Head Gasket Failure

Rod Bearing Failure from Oil Starvation (Track Use)

Interference-engine timing belt / hydraulic tensioner failure

2.0L head gasket failure (original composite gasket) — SOHC and DOHC

Intake Plenum Pan Gasket Failure (Magnum V6/V8) Causing Oil Consumption and Misfire

P0300 code reference

Frequently asked questions