P0520 on Dodge: How to Diagnose & Fix
Engine Oil Pressure Sensor/Switch Circuit Malfunction
3 Dodge models · 3 documented issues · 3 critical · $150-$8,000 repair
P0520 on Dodge by model: symptoms, diagnosis and fix
The 2.7L DOHC V6 engine is one of the most notoriously unreliable engines Chrysler ever produced. Inadequate oil drain-back passages in the cylinder heads allow oil to sit and cook at operating temperature, forming thick sludge deposits that clog oil passages and starve the engine of lubrication. This leads to catastrophic engine seizure, often before 100,000 miles even with proper oil change intervals. The water pump is driven by the timing chain and leaks coolant into the oil, accelerating sludge formation. Multiple class-action lawsuits were filed over this engine.
Common Symptoms
- Oil pressure warning light flickering or staying on
- Engine knocking or ticking noises
- Check engine light with misfire codes
- Oil cap shows thick sludge buildup
- Sudden catastrophic engine seizure
How to Fix
Sources for this issue (1)
The 2.7L V6 in the Magnum is notorious for oil sludge buildup that clogs oil passages and starves critical engine components of lubrication. The engine has a small oil pan, undersized oil pump, and a water pump design that can leak coolant internally. Combined with the crankcase ventilation system allowing hydrocarbons to break down oil additives, these factors cause thick sludge to form even with regular oil changes. Oil starvation damages bearings, camshafts, and timing chain components, often leading to catastrophic engine failure at relatively low mileage.
Common Symptoms
- Low oil pressure warning light illuminating
- Ticking or knocking sounds from engine, especially at startup
- Oil level drops faster than normal between changes
- Milky or thick residue under oil cap
- Engine overheating due to clogged oil cooler passages
- Check engine light with oil pressure or timing codes
How to Fix
Use full synthetic oil and change every 3,000-4,000 miles maximum. Have the engine oil flushed if sludge is suspected. Replace the water pump proactively at 80,000-100,000 miles to prevent internal coolant leaks. If the engine is already sludged, professional engine cleaning may help in early stages. If bearings are damaged, engine replacement ($4,000-$8,000) is usually required as rebuild costs are comparable.
Sources for this issue (1)
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…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (1)
P0520 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 P0520 mean on a Dodge?
P0520 stands for "Engine Oil Pressure Sensor/Switch Circuit Malfunction." This code indicates a general electrical fault in the circuit for the engine oil pressure sensor or switch. The computer monitors this circuit to know your oil pressure, and it has detected a signal that is missing, shorted, or otherwise out of the expected electrical range. This is typically a wiring or sensor problem rather than an actual loss of oil pressure, but because oil pressure is critical to engine life, it should never be ignored until confirmed. If oil pressure truly is low, serious engine damage can result. On Dodge it is documented across 3 models: Intrepid, Magnum, Stratus.
What are the most common causes of P0520?
The most common causes of P0520 are: Faulty oil pressure sensor or switch, Damaged, corroded, or loose wiring/connector at the sensor, Open or short in the sensor circuit wiring, Poor ground connection, Low engine oil level or genuinely low oil pressure, Failed PCM/ECM (less common). The specific cause varies by vehicle.
How much does it cost to fix P0520 on a Dodge?
Published repair estimates on Dodge range from $150 to $8,000 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.
Looking for P0520 on a different make?
View P0520 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.