BMW · Known Issues

2018 BMW M240i Problems: 10 Known Issues

2018 model year · 925+ owner reports · Updated August 2026

According to Au7o's analysis of 925+ owner reports, the 2018 BMW M240i has 10 documented known issues, with 4 rated critical. The most serious are F2x Cylinder-Head Coolant Vent-Line Service Action, Crankshaft Position Sensor Firmware Error Causing Engine Stall - Recall 18V-465 ($0-$0 repair), B58 Polycarbonate Oil Filter Housing Embrittlement Leaking Coolant and Oil ($1,800-$3,500 repair) and Electric Coolant Pump and Integrated Thermostat Housing Failure ($700-$1,400 repair). The most commonly reported issue is Plastic Charge Pipe Failure Under Boost with 340 owner reports. Across all issues with published estimates, repair costs range from $150 to $3,500. DIY maintenance guides at au7o.io.

Frequently Asked Questions

What are the most common BMW M240i problems?

According to Au7o's analysis of 925+ owner reports, the 2018 BMW M240i has 10 documented issues. The most frequently reported are: F2x Cylinder-Head Coolant Vent-Line Service Action, Crankshaft Position Sensor Firmware Error Causing Engine Stall - Recall 18V-465, B58 Polycarbonate Oil Filter Housing Embrittlement Leaking Coolant and Oil. Of these, 4 are rated critical and should be addressed promptly.

Is the BMW M240i reliable?

The 2018 BMW M240i has 10 known issues documented across 925+ owner reports. 4 issues are rated critical: F2x Cylinder-Head Coolant Vent-Line Service Action and Crankshaft Position Sensor Firmware Error Causing Engine Stall - Recall 18V-465 and B58 Polycarbonate Oil Filter Housing Embrittlement Leaking Coolant and Oil and Electric Coolant Pump and Integrated Thermostat Housing Failure. 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 M240i problems?

Repair costs for known BMW M240i issues range from $0 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 2017-2020 BMW M240i F2x Cylinder-Head Coolant Vent-Line Service Action?

BMW SIB 17 01 21 covers affected F22 and F23 vehicles produced from April 24, 2015 through September 24, 2019. The quick-disconnect coupling on the cylinder-head coolant vent line can break at the cylinder head because the line may not withstand high temperatures over its service… Severity: high.

What is the 2018-2019 BMW M240i Crankshaft Position Sensor Firmware Error Causing Engine Stall - Recall 18V-465?

An updated firmware level loaded into the crankshaft sensor's semiconductor contained an error that could cause the sensor to fail to process the input from the crankshaft reluctor ring. The result is a sudden engine stall while driving. The campaign was opened in August 2018 cov… Repairs typically run $0-$0. Severity: high.

What is the 2017-2023 BMW M240i B58 Polycarbonate Oil Filter Housing Embrittlement Leaking Coolant and Oil?

The B58's engine oil filter housing doubles as an oil-to-coolant heat exchanger and is molded from polycarbonate rather than cast aluminum. Heat cycling and vibration embrittle the plastic, and the housing cracks or its gaskets harden so that coolant weeps past the internal coola… Repairs typically run $1,800-$3,500. Severity: high.

What is the 2017-2024 BMW M240i Electric Coolant Pump and Integrated Thermostat Housing Failure?

The B58 uses a fully electric, DME-controlled coolant pump integrated with the thermostat housing. The pump's plastic impeller and its housing seals degrade under the heat cycling of a turbocharged inline six, and the unit either seeps coolant from the housing seam or loses comma… Repairs typically run $700-$1,400. Severity: high.

What is the 2017-2024 BMW M240i Plastic Charge Pipe Failure Under Boost?

The B58 engine uses a plastic charge pipe to route compressed air from the turbocharger to the throttle body. Under sustained high boost conditions, the factory plastic charge pipe can crack, split, or blow off, resulting in an immediate and total loss of boost pressure. This fai… Repairs typically run $200-$600. Severity: medium.

What is the 2017-2024 BMW M240i Valve Cover Gasket Oil Leak?

The B58 engine's valve cover gasket is prone to degradation and oil leaks, typically developing around 60,000-100,000 miles. The rubber gasket material shrinks and dries out through repeated heat cycles, allowing oil to seep and eventually drip down the sides of the engine. In mo… Repairs typically run $500-$900. Severity: medium.

What is the 2017-2024 BMW M240i VANOS Solenoid O-Ring Failure?

The B58 engine's VANOS solenoid o-rings degrade due to wear and high temperatures, causing oil leaks and variable valve timing faults. When the o-rings fail, oil pressure to the VANOS system is compromised, leading to rough idle, reduced power, and check engine lights. This is a… Repairs typically run $150-$500. Severity: medium.

What is the 2017-2024 BMW M240i B58 Direct Injector Seal Failure Causing Misfire and Fuel Dilution?

The B58's solenoid direct injectors sit in the head behind Teflon sealing rings. As the seal hardens and the injector's internals wear, the injector either leaks down into the cylinder after shutdown or delivers an off-spec spray pattern. Owners report cylinder-specific misfires,… Repairs typically run $250-$1,200. Severity: medium.

What is the 2018 BMW M240i Instrument Cluster Display Fails to Illuminate Warning Symbols - Recall 17V-719?

BMW opened a voluntary non-compliance recall effective November 10, 2017 covering 2018 2 Series Coupe, 2 Series Convertible, M2 and X3 models, M240i included. A software error in the instrument cluster meant the display could fail to illuminate properly - either not coming up at… Repairs typically run $0-$0. Severity: medium.

What is the 2017-2024 BMW M240i B58 High-Pressure Fuel Pump Cannot Hold Rail Pressure Under Load?

The M240i runs a two-pump fuel system - an in-tank low-pressure pump feeding a cam-driven high-pressure pump on the B58's head. As the HPFP's internal valve and cam follower wear, the pump can still idle and cruise normally but cannot maintain commanded rail pressure during hard… Repairs typically run $700-$1,400. Severity: medium.

All 10 Known Issues

2017-2020 BMW M240i: F2x Cylinder-Head Coolant Vent-Line Service Action#

2017-2023 BMW M240i: B58 Polycarbonate Oil Filter Housing Embrittlement Leaking Coolant and Oil#

2017-2024 BMW M240i: Electric Coolant Pump and Integrated Thermostat Housing Failure#

2018-2019 BMW M240i: Crankshaft Position Sensor Firmware Error Causing Engine Stall - Recall 18V-465#

2017-2024 BMW M240i: Plastic Charge Pipe Failure Under Boost#

2017-2024 BMW M240i: Valve Cover Gasket Oil Leak#

2017-2024 BMW M240i: VANOS Solenoid O-Ring Failure#

2017-2024 BMW M240i: B58 Direct Injector Seal Failure Causing Misfire and Fuel Dilution#

2018 BMW M240i: Instrument Cluster Display Fails to Illuminate Warning Symbols - Recall 17V-719#

2017-2024 BMW M240i: B58 High-Pressure Fuel Pump Cannot Hold Rail Pressure Under Load#

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