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BMW · Known Issues

2015 BMW 4 Series Problems: 8 Known Issues

2015 model year · 200+ owner reports · Updated September 2026

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Issue summary

According to Au7o's analysis of 200+ owner reports, the 2015 BMW 4 Series has 8 documented known issues, with 2 rated critical. The most serious are Lower-Engine Whine Requires 428i N20/N26 Timing-Chain Diagnosis and N20 Timing Chain Premature Failure - 428i F32/F33/F36 ($2,500-$4,500 repair). The most commonly reported issue is Valve Cover Gasket Leak and PCV Failure with 200 owner reports. Across all issues with published estimates, repair costs range from $150 to $4,500. DIY maintenance guides at au7o.io.

In This Article

  • 4 Series Engine7
  • 4 Series Body/Panels1
  • FAQ
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In This Article

  • Engine7
  • Body/Panels1
  • FAQ

All 8 Known Issues

Filter:
ALL YEARS202520242023202220212020201920182017201620152014

When Issues Typically Appear

N20 Timing Chain Premature Failure - 428i F32/F33/F36
40K-80K
Turbo Charge Pipe Failure - 428i/435i/440i F32/F33/F36
50K-80K
Valve Cover Gasket Leak and PCV Failure
60K-90K
N55 Electric Water Pump Failure - 435i/440i F32/F33/F36
60K-100K
Fuel Injector Failure - 428i/430i/435i/440i F32/F33/F36
60K-100K
025K50K75K100K mi

On the 2014-2015 BMW 4 Series, bMW SIB 11 03 17 identifies specified F32, F33 and F36 428i variants with N20 or N26 engines produced through February 2015. A whining noise from the lower engine area that rises with engine speed can be associated with wear in the timing-chain or oil-pump drive-chain system; the bulletin does not declare every 428i defective.

This issue also affects: BMW 1 Series, BMW 2 Series, BMW 3 Series

Common Symptoms

  • Whining from the lower engine area
  • Noise frequency increases with engine speed

How to Fix

Confirm the exact chassis, engine, production date and VIN eligibility, then have a BMW-qualified technician reproduce the noise and follow the current BMW diagnostic procedure before replacing anything. The historical seven-year/70,000-mile coverage was a limited warranty extension, not a recall, and is not a current coverage promise. ShowMeTheParts returned no exact 2014 428i timing-chain candidate, so no commerce link is approved.

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NHTSA Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 2014-2016 BMW 4 Series N20, the N20 2.0L turbocharged engine in 428i models suffers from premature timing chain stretch and guide failure, typically occurring between 40,000-80,000 miles. The single-row timing chain design is inadequate for the engine's power output. Chain stretch causes the timing to jump, leading to rough running, poor performance, and potential catastrophic engine damage if the chain breaks. BMW issued a class action settlement covering 8 years/100,000 miles. This is identical to the N20 timing chain issue in 328i/X3/X5 models using the same engine.

This issue also affects: BMW 1 Series, BMW 2 Series Active Tourer, BMW 2 Series

Common Symptoms

  • Rattling noise from engine on cold start (first 5 seconds)
  • Check engine light with timing correlation codes (P0016, P0017, P0018, P0019)
  • Rough idle or misfires
  • Loss of power or hesitation on acceleration
  • Engine won't start after chain failure

How to Fix

Complete timing chain kit replacement including chain, guides, tensioner, and sprockets. Must be performed by experienced BMW technician. Preventive replacement recommended at 60,000-80,000 miles. BMW extended warranty to 8 years/100,000 miles under class action settlement. Upgraded reinforced chain kit available from aftermarket.

What you need to fix it

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

  • Iwis N20 timing-chain kit 11315A19AA2

    Fitment: F32/F33/F36 BMW 428i and 428i xDrive with N20 as listed by Turner; use the vehicle selector and confirm VIN/production date. Kit lists chain, gaskets, guides/rails, sprocket and hardware; technician must confirm any additional o…

    Turner Motorsport

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$2,500 - $4,500

Research This Issue

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Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026
Community reported
200 owners

On the 2014-2020 BMW 4 Series, the valve cover gasket on N20 (428i) and N55 (435i) engines develops leaks typically between 60,000-90,000 miles. The integrated PCV valve within the valve cover can also fail, causing excessive crankcase pressure, oil consumption, and rough running. Oil seepage from the valve cover can contaminate spark plug wells and cause misfires.

This issue also affects: BMW 1 Series, BMW 2 Series, BMW 3 Series

Common Symptoms

  • Oil smell from engine bay, stronger when parked after driving
  • Oil residue visible on valve cover edges
  • Rough idle from failed PCV valve
  • Whistling or sucking noise from engine (PCV vacuum leak)
  • Increased oil consumption between changes
  • Misfires from oil in spark plug wells

How to Fix

Replace the entire valve cover assembly as the gasket and PCV are integrated into the plastic cover on both N20 and N55 engines. Clean spark plug wells of any oil contamination and replace spark plugs if oil-fouled. Use a torque wrench to properly seat the new cover — over-tightening cracks the plastic housing.

What you need to fix it

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

  • Genuine BMW N20 cylinder-head-cover gasket set 11127588418
    OEM11127588418

    Fitment: 2014-2016 F32/F33/F36 BMW 428i with N20; confirm VIN and required companion seals, fuel line and fasteners in the BMW diagram..

    BMW Parts Deal
  • Genuine BMW N20 cylinder-head cover 11127588412
    OEM11127588412

    Fitment: 2014-2016 F32/F33/F36 BMW 428i with N20; confirm N20 rather than N26 and order BMW-diagram companion parts required for the VIN..

    BMW Parts Deal
  • Genuine BMW N55 valve-cover profile gasket 11127587804
    OEM11127587804

    Fitment: 2014-2016 F32/F33 and 2015-2016 F36 BMW 435i/435i xDrive with N55; confirm VIN and companion seals..

    BMW Parts Deal
  • Genuine BMW N55 cylinder-head cover 11127570292
    OEM11127570292

    Fitment: 2014-2016 F32/F33 and 2015-2016 F36 BMW 435i/435i xDrive with N55; confirm VIN and BMW-diagram companion fasteners..

    BMW Parts Deal

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$500 - $1,200

Research This Issue

Based on 200 owner reports

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Community Reported
High ConfidenceVerified200 owner reportsLast reported by owners Mar 2026Reviewed Aug 2026

On the 2014-2018 BMW 4 Series N55, the N55 engine uses an electric auxiliary water pump (in addition to the mechanical pump) that commonly fails between 60,000-100,000 miles. The electric pump circulates coolant when the engine is off to prevent heat soak and during cold starts. Pump bearing wear and seal failure lead to coolant leaks and pump motor burnout. Symptoms include coolant loss, overheating warnings, and heater malfunction. This is a wear item that will eventually fail on all N55 engines (also affects 335i, 535i, X5 35i, X6 35i).

This issue also affects: BMW 1 Series, BMW 2 Series, BMW 5 Series

Common Symptoms

  • Coolant warning light or low coolant message
  • Visible coolant leak under vehicle (passenger side)
  • Overheating warning or temperature gauge rising
  • Heater not working properly
  • Whining noise from water pump area
  • Check engine light with coolant circulation codes

How to Fix

Replace electric water pump. Also inspect main mechanical water pump and thermostat for leaks/failure while repair is being performed. Replace coolant with BMW-approved coolant (blue or newer orange). Bleed cooling system properly after replacement to avoid air pockets. Some mechanics recommend replacing both pumps together since labor overlaps.

What you need to fix it

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

  • Genuine BMW N55 electric coolant pump 11518635090
    OEM11518635090

    Confirmed failed N55 main electric coolant-pump replacement. Fitment: 2014-2016 F32/F33 and 2015-2016 F36 BMW 435i/435i xDrive with N55 as cataloged; confirm VIN and required bolts, hoses and coolant before ordering..

    BMW Parts Deal

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$400 - $900

Research This Issue

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Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026

On the 2014-2018 BMW 4 Series, the N55 3.0L turbocharged inline-6 engine in 435i and early 440i models experiences VANOS (Variable Valve Timing) solenoid failures. These solenoids control oil flow to the VANOS system for variable valve timing. Internal wear causes them to stick or fail, leading to rough running, power loss, and check engine lights. The intake VANOS solenoid (cylinder head front) fails more frequently than the exhaust solenoid. Oil contamination and sludge accelerate failure. This is a common issue shared with N55-powered 335i, 535i, and X5 35i models.

This issue also affects: BMW 7 Series, BMW 8 Series, BMW M2

Common Symptoms

  • Rough idle or engine stumble
  • Check engine light with VANOS codes (P0011, P0012, P0021, P0022)
  • Loss of power or poor throttle response
  • Increased fuel consumption
  • Cold start rough running that improves when warm

How to Fix

Replace failed VANOS solenoid(s). Both intake and exhaust solenoids should be inspected. Clean VANOS system if contaminated with sludge. Use high-quality full synthetic oil (BMW LL-01 spec) and maintain 7,500-mile oil change intervals to prevent premature failure. Some shops recommend replacing both solenoids preventively.

What you need to fix it

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

  • Genuine BMW N55 VANOS solenoid valve 11368605123
    OEM11368605123

    BMW catalogs quantity two but replace only the diagnosed failed position unless the repair plan calls for both; confirm VIN..

    BMW Parts Deal

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$250 - $800

Research This Issue

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Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026

On the 2014-2020 BMW 4 Series, direct injection fuel injectors on N20 and N55 engines commonly fail between 60,000-100,000 miles due to carbon buildup and high-pressure operation. Injector internal seals wear out, causing fuel leaks or inconsistent spray patterns. Failed injectors cause rough running, misfires, and poor fuel economy. Carbon deposits on intake valves (common on direct injection engines) worsen the problem. BMW uses Bosch high-pressure injectors that operate at 2,000+ PSI. When one injector fails, others often follow soon after.

This issue also affects: BMW 3 Series, BMW M3, BMW X6

Common Symptoms

  • Rough idle or engine vibration
  • Check engine light with misfire codes (P0300-P0306)
  • Loss of power or hesitation
  • Increased fuel consumption
  • Hard starting or long cranking
  • Fuel smell from engine bay (injector leak)

How to Fix

Replace failed injector(s). BMW recommends replacing all injectors together to prevent repeat repairs. Perform walnut blast carbon cleaning on intake valves while injectors are out (labor overlap saves money). Use Top Tier gasoline with detergent additives to minimize carbon buildup. Some owners add Liqui Moly Valve Clean to fuel tank every 5,000 miles preventively.

Typical repair cost:$800 - $2,500

Research This Issue

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Community Reported
Medium Confidence

On the 2014-2020 BMW 4 Series, bMW uses a plastic charge pipe (boost pipe) to route pressurized air from the turbocharger to the engine intake. The plastic becomes brittle over time due to heat cycles and boost pressure. The pipe commonly cracks or the connection points fail, causing a sudden loss of boost pressure. This results in immediate power loss and limp mode. The failure typically occurs between 50,000-80,000 miles. All turbocharged F-chassis BMWs (N20, N55 engines) are affected. Many owners upgrade to aluminum charge pipes to prevent recurrence.

This issue also affects: BMW 1 Series, BMW 2 Series, BMW 3 Series

Common Symptoms

  • Sudden loss of power while driving
  • Loud hissing or whooshing sound from engine bay
  • Check engine light with boost pressure codes (P0299, P0234)
  • Limp mode activation (reduced power)
  • Visible crack or separation in charge pipe
  • Engine runs but lacks power under acceleration

How to Fix

Replace charge pipe. OEM replacement is plastic and will fail again. Aftermarket aluminum charge pipe is highly recommended for permanent fix. Popular brands: ARM Motorsports, Burger Motorsport (BMS), VRSF. Installation is straightforward DIY for experienced mechanics. Also inspect intercooler boots and clamps for cracks while charge pipe is removed.

What you need to fix it

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

  • VRSF N20/N26 F32/F33/F36 428i charge-pipe upgrade

    Fitment: 2014-2016 F32/F33/F36 BMW 428i and 428i xDrive with N20/N26; confirm engine and chassis before ordering..

    VR Speed
  • BMS B46/B48 F32/F33/F36 430i charge pipe
    OEM13718601683

    Fitment: 2017-2020 F32/F33/F36 BMW 430i, including Gran Coupe, Convertible and xDrive; select the Gen 1 & 2 B46/B48 option and confirm OE pipe number 13718601683..

    Burger Tuning
  • VRSF N55 F32/F33/F36 435i charge-pipe upgrade

    N55 435i failed charge-pipe replacement. Fitment: 2014-2016 F32/F33 and 2015-2016 F36 BMW 435i/435i xDrive with N55; select the exact RWD/xDrive and automatic/manual option..

    VR Speed
  • BMS Elite Gen1 B58 F32/F33/F36 440i aluminum charge pipe

    Fitment: 2017-2020 F32/F33/F36 BMW 440i, including xDrive and Gran Coupe, with Gen1 B58; select the correct engine option..

    Burger Tuning

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$150 - $600

Research This Issue

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Community Reported
Medium ConfidenceVerifiedReviewed Aug 2026

On the 2014-2020 BMW 4 Series, the F33 4 Series convertible uses a complex hydraulic folding hardtop system that commonly experiences pump and motor failures. The hydraulic pump motor burns out from overheating or seal leaks cause hydraulic fluid loss. Top becomes stuck in partially open/closed position. Microswitch sensors that detect top position also fail frequently, preventing top operation even when hydraulics work. Exposure to weather and infrequent operation accelerate failures. This affects all F33 convertibles and is similar to issues in E93 3 Series convertibles.

Common Symptoms

  • Convertible top stuck partially open or closed
  • Top operation warning message on iDrive
  • Whining or grinding noise when operating top
  • Top moves slowly or stops mid-cycle
  • Hydraulic fluid leak in trunk area
  • Top won't unlatch or latch properly

How to Fix

Diagnose specific failure point - pump motor, hydraulic lines, microswitches, or latch mechanisms. Hydraulic pump motor replacement is most common repair. Check hydraulic fluid level and refill if low. Inspect all microswitches and sensors for proper operation. Regular top cycling (once per month minimum) prevents seals from drying out. Store with top up to reduce strain on hydraulics.

Typical repair cost:$1,200 - $3,500

Research This Issue

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Community Reported
Medium Confidence
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Frequently Asked Questions

What are the most common BMW 4 Series problems?

According to Au7o's analysis of 200+ owner reports, the 2015 BMW 4 Series has 8 documented issues. The most frequently reported are: Lower-Engine Whine Requires 428i N20/N26 Timing-Chain Diagnosis, N20 Timing Chain Premature Failure - 428i F32/F33/F36, Valve Cover Gasket Leak and PCV Failure. Of these, 2 are rated critical and should be addressed promptly.

Is the BMW 4 Series reliable?

The 2015 BMW 4 Series has 8 known issues documented across 200+ owner reports. 2 issues are rated critical: Lower-Engine Whine Requires 428i N20/N26 Timing-Chain Diagnosis and N20 Timing Chain Premature Failure - 428i F32/F33/F36. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common BMW 4 Series problems?

Repair costs for known BMW 4 Series issues range from $150 to $4,500, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2014-2015 BMW 4 Series Lower-Engine Whine Requires 428i N20/N26 Timing-Chain Diagnosis?

BMW SIB 11 03 17 identifies specified F32, F33 and F36 428i variants with N20 or N26 engines produced through February 2015. A whining noise from the lower engine area that rises with engine speed can be associated with wear in the timing-chain or oil-pump drive-chain system; the… Severity: high.

What is the 2014-2016 BMW 4 Series N20 Timing Chain Premature Failure - 428i F32/F33/F36?

The N20 2.0L turbocharged engine in 428i models suffers from premature timing chain stretch and guide failure, typically occurring between 40,000-80,000 miles. The single-row timing chain design is inadequate for the engine's power output. Chain stretch causes the timing to jump,… Repairs typically run $2,500-$4,500. Severity: high.

Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

Data sourced from 200+ owner reports, NHTSA recalls, TSBs, and automotive forums.

What is the 2014-2020 BMW 4 Series Valve Cover Gasket Leak and PCV Failure?

The valve cover gasket on N20 (428i) and N55 (435i) engines develops leaks typically between 60,000-90,000 miles. The integrated PCV valve within the valve cover can also fail, causing excessive crankcase pressure, oil consumption, and rough running. Oil seepage from the valve co… Repairs typically run $500-$1,200. Severity: medium.

What is the 2014-2020 BMW 4 Series Convertible Top Hydraulic Pump & Motor Failure - F33 Convertible?

The F33 4 Series convertible uses a complex hydraulic folding hardtop system that commonly experiences pump and motor failures. The hydraulic pump motor burns out from overheating or seal leaks cause hydraulic fluid loss. Top becomes stuck in partially open/closed position. Micro… Repairs typically run $1,200-$3,500. Severity: medium.

What is the 2014-2018 BMW 4 Series N55 Electric Water Pump Failure - 435i/440i F32/F33/F36?

The N55 engine uses an electric auxiliary water pump (in addition to the mechanical pump) that commonly fails between 60,000-100,000 miles. The electric pump circulates coolant when the engine is off to prevent heat soak and during cold starts. Pump bearing wear and seal failure… Repairs typically run $400-$900. Severity: medium.

What is the 2014-2018 BMW 4 Series N55 VANOS Solenoid Failure - 435i/440i F32/F33/F36?

The N55 3.0L turbocharged inline-6 engine in 435i and early 440i models experiences VANOS (Variable Valve Timing) solenoid failures. These solenoids control oil flow to the VANOS system for variable valve timing. Internal wear causes them to stick or fail, leading to rough runnin… Repairs typically run $250-$800. Severity: medium.

What is the 2014-2020 BMW 4 Series Fuel Injector Failure - 428i/430i/435i/440i F32/F33/F36?

Direct injection fuel injectors on N20 and N55 engines commonly fail between 60,000-100,000 miles due to carbon buildup and high-pressure operation. Injector internal seals wear out, causing fuel leaks or inconsistent spray patterns. Failed injectors cause rough running, misfires… Repairs typically run $800-$2,500. Severity: medium.

What is the 2014-2020 BMW 4 Series Turbo Charge Pipe Failure - 428i/435i/440i F32/F33/F36?

BMW uses a plastic charge pipe (boost pipe) to route pressurized air from the turbocharger to the engine intake. The plastic becomes brittle over time due to heat cycles and boost pressure. The pipe commonly cracks or the connection points fail, causing a sudden loss of boost pre… Repairs typically run $150-$600. Severity: medium.