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BMW · Known Issues

2020 BMW 4 Series Problems: 5 Known Issues

2020 model year · 450+ owner reports · Updated September 2026

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2020 · All trims · All engines

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Issue summary

According to Au7o's analysis of 450+ owner reports, the 2020 BMW 4 Series has 5 documented known issues. None of the listed issues is rated critical; this is not a complete reliability assessment. The most commonly reported issue is B58 Charge Pipe Pop-Off Under Boost with 250 owner reports. Across all issues with published estimates, repair costs range from $150 to $3,500. DIY maintenance guides at au7o.io.

In This Article

  • 4 Series Engine4
  • 4 Series Body/Panels1
  • Recalls1
  • FAQ
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In This Article

  • Engine4
  • Body/Panels1
  • Recalls1
  • FAQ

All 5 Known Issues

Filter:
ALL YEARS202520242023202220212020201920182017201620152014

When Issues Typically Appear

Turbo Charge Pipe Failure - 428i/435i/440i F32/F33/F36
50K-80K
Valve Cover Gasket Leak and PCV Failure
60K-90K
Fuel Injector Failure - 428i/430i/435i/440i F32/F33/F36
60K-100K
025K50K75K100K mi
Community reported
250 owners

On the 2017-2025 BMW 4 Series B58, the plastic charge pipe (intercooler to throttle body) on B58-powered 440i and M440i models can pop off or crack under high boost pressure, especially in warm weather or during spirited driving. The OEM plastic pipe uses a pressed-on connector that weakens over heat cycles. When the pipe disconnects, the engine immediately loses boost pressure and enters limp mode with significant power loss.

This issue also affects: BMW 2 Series, BMW 5 Series, BMW M5

Common Symptoms

  • Sudden loss of power during hard acceleration
  • Loud pop or hissing sound from engine bay
  • Boost pressure fault codes stored in DME
  • Check Engine light with underboost code
  • Engine running rough after the pipe disconnects
  • Whistling or whooshing noise under throttle

How to Fix

Replace the OEM plastic charge pipe with an upgraded aluminum aftermarket unit. These use proper clamp-style connections that won't pop off under pressure. If replacing with OEM, use the latest revision part number. Check the intercooler boots and couplings for damage from the pressure release event.

What you need to fix it

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

  • BMS Elite Gen1 B58 F-chassis aluminum charge pipe

    Select the correct engine option and confirm chassis before ordering..

    Burger Tuning
  • BMS B58TU Gen2 G-chassis charge pipe

    The vendor page does not currently confirm 2025, so do not extend this link to 2025 without revalidation..

    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:$200 - $500

Research This Issue

Based on 250 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerified250 owner reportsLast reported by owners Mar 2026Reviewed 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

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

GoogleRedditYouTubeNHTSA
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

GoogleRedditYouTubeNHTSA
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

GoogleRedditYouTubeNHTSA
Community Reported
Medium Confidence
NHTSA Recalls1 recall

POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM)

BMW of North America, LLC (BMW) is recalling certain 2023 Toyota GR Supra, 3 Series Sedan (330i xDrive, M340i xDrive, M3), 5 Series Sedan (530i, 530i xDrive, M5), 4 Series Gran Coupe (430i, 430i xDrive), 4 Series Coupe (430i, 430i xDrive, M440i xDrive), 4 Series Convertible (430i, 430i xDrive, M440i xDrive), 8 Series Coupe (840i, M850i xDrive, M8), 8 Series Convertible (840i, M850i xDrive, M8), 8 Series Gran Coupe (850i xDrive, M8), X3 SAV (X3 xDrive30i, X3M), X4 SAV (X4 xDrive30i), X5 SAV (X5 xDrive40i, X5 M50i, X5M), X6 SAV (X6 xDrive40i, X6 M50i, X6M), and Z4 sDrive30i, Z4 M40i vehicles. The weld seam of the integrated transmission control unit's cover may not have been manufactured properly, which could allow automatic transmission oil to leak into the transmission control unit.

Campaign #23V82100006/12/2023

Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

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Other BMW Models

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Frequently Asked Questions

What are the most common BMW 4 Series problems?

According to Au7o's analysis of 450+ owner reports, the 2020 BMW 4 Series has 5 documented issues. The most frequently reported are: B58 Charge Pipe Pop-Off Under Boost, Valve Cover Gasket Leak and PCV Failure, Convertible Top Hydraulic Pump & Motor Failure - F33 Convertible. None are rated critical, but regular maintenance is recommended.

Is the BMW 4 Series reliable?

The 2020 BMW 4 Series has 5 known issues documented across 450+ owner reports. None of the matching records is rated critical; this is not a complete reliability assessment. 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 $3,500, 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 2017-2025 BMW 4 Series B58 Charge Pipe Pop-Off Under Boost?

The plastic charge pipe (intercooler to throttle body) on B58-powered 440i and M440i models can pop off or crack under high boost pressure, especially in warm weather or during spirited driving. The OEM plastic pipe uses a pressed-on connector that weakens over heat cycles. When… Repairs typically run $200-$500. Severity: medium.

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?

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 450+ owner reports, NHTSA recalls, TSBs, and automotive forums.

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 2014-2020 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.