2020 BMW M340i Problems

Complaints Reported

Complaints by Component

ENGINE

13 complaints

I cruised on a city street at the speed limit. The light turned red and I came to a full stop. The start/stop system was activated and the engine “stopped” to conserve power while my foot was on the brake. The light turned green and I took my foot off the brake, the engine failed to start and did not start with countless attempts. Digital cluster and CarPlay proceeded to work, exterior lights work. Called a tow to the nearest BMW dealership for assistance.

Apr 18, 2025

Car will not measure oil past 20%. Seems like lots of 2020 models have a faulty production oil pump. Car is now out of warranty and dealer charged $5000 to fix the issue but do not know 100% if oil pump replacement will fix it. BMW changed the oil pump in the later models but did not mention anything about any recalls or replacements. Unacceptable.

Apr 03, 2025

I am unable to read the oil level in my 2020 M340i. Upon checking the oil pressure, the oil pressure goes above 45psi which is the cutoff for the measurement check. Under heavy acceleration, the oil pressure will go over 90psi. My car needs the oil pump to be replaced. The plastic ring surrounding the oil pump for variable oil pressure will crack and lead to a high oil pressure scenario, eventually leading to catastrophic engine damage. BMW has refused to acknowledge this even though they installed an updated all-metal oil pump in 2021 and newer M340i.

Mar 17, 2025

Oil pump manufacturing fault. One of the internal components on the oil pump for these B58 engines contains a ring that is made of plastic. Due to its the nature of this type of material, when it is heated and cooled, over time it becomes brittle and cracks. Damage to this internal component is leading to oil pump failure, and eventually engine failure. There is no recall on this yet, which is highly concerning. Basically my oil pump is a ticking time bomb waiting to fail, and BMW refuses to address the issue. Attached are photos of different oil pumps from the exact same engine as mine, containing the plastic ring which is visibly damaged from repeated exposure to hot and cold temperature fluctuations. Once this ring goes bad, engine damage may be catastrophic.

Mar 04, 2025

Oil level won’t read. Can cause engine issues. Car has no dipstick to check for oil

Sep 26, 2024

+ 8 more complaints for this component

UNKNOWN OR OTHER,ENGINE

3 complaints

Oil pump common issue of made out plastic cause miss interpretation of oil pressure. Developing engine issues under 50k miles

Sep 29, 2025

Hi. I’d like to point out I have not had an incident YET thankfully. However, I want to highlight that the early M340i production releases (2019 and 2020) are HIGHLY likely to experience catastrophic engine failure due to an oil pump being made of plastic on some models. Of the 20 or so complaints listed under this vehicle on NHTSA, I’ve already seen PLENTY of complaints regarding this issue and people actually experiencing this issue. I believe if a car has a fair chance of causing catastrophic damage to its engine on its own, it poses as a safety risk for anyone in or around the car. The fix is to spend $6000-$7000 to have the oil pump replaced with the new 2021 oil pump, but most normal people cannot afford that easily and are driving around with plastic pumps still hoping for the best. I don’t understand how so many complaints of the same safety issue on this website for this vehicle (and other vehicles, which have the same B58 engine) have not resulted in a recall. Hopefully this can change because a car destroying itself shouldn’t be taken lightly and I’d like to second what everyone else on here is saying about the oil pump issue.

Sep 23, 2025

Oil pump failure, causing inability to read oil level. Also flickering oil light on and off. After some research noticed it was happening to a lot of others as well due to oil pump being made with plastic internals. BMW has since updated to a new pump with metal internal the next year however never recalled old pumps.

Jul 25, 2024

UNKNOWN OR OTHER

3 complaints

Oil pump on 2020 models is a constant issue. They fail after about 15k miles and BMW refuses to recognize this as a recall issue.

Apr 21, 2023

THE FRONT COLLISION SYSTEM DOES NOT WORK. EARLY WARNING RARELY COMES ON, AND IN A RECENT NEAR CRASH ON THE DALLAS NORTH TOLLWAY, IT NEVER CAME ON. EVERY NOW AND THEN, THE EARLY WARNING FRONT COLLISION WARNING WILL COME ON FOR A SECOND, BUT THERE IS NO REASON FOR IT. I TOOK IT TO THE LOCAL DEALERSHIP (CLASSIC BMW) AND THEY SAID IT IS OPERATING AS NORMAL ,ALTHOUGH TO PROVE IT THEY HAD TO TAILGATE CARS AT 75 MPH TO SIMPLY GET THE EARLY WARNING LIGHT TO ILLUMINATE A FEW TIMES. THEY NEVER GOT THE IMMINATE CRASH WARNING TO COME ON. THIS SYSTEM IS UNSAFE AND DOES NOT PROVIDE THE PROTECTION IT ADVERTISES. I'VE DRIVEN SEVERAL OTHER MAKES THAT HAD THIS SYSTEM, AND THE EARLY WARNING COMES ON VERY EARLY, WHEN YOU ARE BARELY NEAR THE CAR IN FRONT OF YOU.

Sep 13, 2020

I WAS DRIVING ON THE HIGHWAY AT APPROXIMATELY 70 MPH, THE POSTED LIMIT, WHEN ALL OF A SUDDEN THE SUNROOF EXPLODED. IT SOUNDED LIKE A GUNSHOT AND I ALMOST LOST CONTROL OF THE VEHICLE. LUCKILY THE HEADLINER WAS CLOSED SO THE GLASS DID NOT ENTER THE CABIN. THERE WERE NO VEHICLES IN FRONT OF US FOR AT LEAST 1 MILE AND NO OVERPASSES OR ROCKS THAT I SAW OR HEARD HITTING THE VEHICLE. IT IS A STOCK VEHICLE WITH 5200 MILES ON IT.

Jul 16, 2020

FUEL/PROPULSION SYSTEM

2 complaints

My vehicle doesn’t read the oil level since the fuel pump that BMW used to manufacture the car is made out of plastic material. There has been hundred of complaints about the same issue with the oil pump not working properly due to the fact that BMW used plastic instead of metal etc. I would like for the NHTSA to take a look at this issue and please consider making it a recall for the users that are having this “Oil Pump” issue please thank you.

May 05, 2025

Oil pump appears to have failed. Told plastic components inside pump. BMW issued a new part number and changed pump to all metal internals. This is standard on later production dates now. Pump failure causes engine failure and oil gauge failure to read out. Head gasket replacement which may or may not be related.

Apr 19, 2023

ELECTRICAL SYSTEM

2 complaints

Engine starter was faulty resulting in repeated attempts to start the engine using excessively long starting attempts and warnings from my car of overheating. At a traffic light, my car went into auto-off and then shut down and I was unable to restart the car leaving me stuck at a busy intersection. I received police support and a tow to the BMW Buena Park dealership. The dealership informed me the issue could be related to an open recall (B120524) which relates to the starter. The dealership replaced the starter but claims the issue is not related to the recall. I have sought for over a month information from the dealership to explain how they determined the faulty starter and recall are not related and have not received anything.

Dec 06, 2024

Starter went bad which lead to shortage within the lithium ion battery and regular battery. Car came to a stop and did not move in an intersection, blocking both lanes of traffic. Furthermore, car could not be put into neutral as it could not be started. There was smoke emanating from the engine on further restart attempts. Car had to be towed where it was determine this was the problem. Warning message during re-start "engine overheated" though temperate guage suggested it was still cold.

Aug 26, 2024

TIRES

2 complaints

I have owned my 2020 BMW m340iX for 2 years. During that time I have had 5 tires blow out, including 3 in the past 3 months alone. The tires are "run flat" and need to be completely replaced if they develop any issues. The dealer I use for service, who is owned by the manufacturer, says it is simply wear and tear - but this pattern is concerning and a potential safety issue for the car and tires.

Dec 10, 2021

TL* THE CONTACT OWNS A 2020 BMW M340I, EQUIPPED WITH PIRELLI TIRES, TIRE LINE: P7 CINTURATO, TIRE SIZE 225/40/R19, DOT NUMBER: NOT AVAILABLE. THE CONTACT STATED THAT WHILE THE VEHICLE WAS AT AN INDEPENDENT MECHANIC FOR SUSPENSION INSPECTION, THE MECHANIC BECAME AWARE OF BUBBLES IN THE DRIVER'S AND PASSENGER'S SIDE FRONT TIRES. THE PASSENGER FRONT TIRE ALSO EXHIBITED A SPLIT. THE TIRES WERE NOT REPLACED. THE MANUFACTURER WAS CONTACTED AND INFORMED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 15,000.

Apr 28, 2020

POWER TRAIN,ENGINE

1 complaint

My oil pump went out causing Low pressure codes and resulting in me paying over 2 grand to get it repaired, They super seeded the oil pump they used to use with a new one and theirs many other reports online etc of the 2020 bmw m340 oil pump going out due to plastic internals which can lead to engine failure .

Nov 03, 2025

ENGINE AND ENGINE COOLING

1 complaint

The contact owns a 2020 BMW M340I. The contact stated that while merging onto the highway and accelerating, there was an abnormally loud banging sound coming from the vehicle before the vehicle stalled. The contact was able to coast forward. There were no warning lights illuminated. The contact removed the panels, and there was metal falling out. The contact stated that there was a sizable hole in the engine, and metal was showing from the cam plate and oil pump. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted regarding recalls and warranty coverage but it was recommended that the contact call the NHTSA Hotline for assistance. The approximate failure mileage was 59,015.

Sep 12, 2025

SERVICE BRAKES

1 complaint

Electronic parking brake malfunction, disengage ineffective. Ongoing 2020 BMW mechanical issue, multiple dealer submissions, BMW refuses to open active recall. BMW requires $3,000 center panel replacement, out-of-pocket.

Sep 03, 2025

ENGINE AND ENGINE COOLING,ELECTRICAL SYSTEM

1 complaint

The contact owns a 2020 BMW M340I. The contact stated that the vehicle was repaired under NHTSA Campaign Number: 24V576000 (Electrical System, Engine and Engine Cooling); however, the repair failed to prevent the failure from occurring. The contact stated that shortly after the recall repair was completed, the vehicle hesitated to start. The contact stated that several employees at the local dealer attempted to start the vehicle. The vehicle started; however, several months later, the failure reoccurred. An appointment with the dealer was scheduled to inspect the vehicle. The vehicle was not repaired and needed to be towed. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 28,162.

May 08, 2025

ELECTRICAL SYSTEM,ENGINE

1 complaint

The starter malfunctioned causing electrical damage to the motor and related components. Although there is literature that exists that this is a potential problem for this vehichle, BMW refuses to fix the problem and is asking me to pay. My warranty is expired by 4 months, but I have only 37,800 miles. The fact that there are 105K vehicles with this potential problem is evidence that this problem exists. They should be paying for what is an obvious manufacturer defect.

Dec 16, 2024

ELECTRICAL SYSTEM,UNKNOWN OR OTHER,ENGINE

1 complaint

Brought my car in for a starter recall picked it up next day and drove home then came out to turn my vehicle on again and it wouldn’t start. Burning smell from engine bay as well. Returned the car they inspected it and told me a faulty starter. When I brought the car in it was in perfect working condition I only brought it for the recall. I was then held accountable for 25% of repair costs.

Aug 21, 2024

UNKNOWN OR OTHER,ENGINE,FUEL/PROPULSION SYSTEM

1 complaint

Unable to read oil level, high or unusually alarming oil pressure. High oil pressure codes

Apr 21, 2023

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4.9/5.0

68 reviews

Frequently Asked Questions

How many problems does the 2020 BMW M340i have?

The 2020 BMW M340i currently has 32 owner-reported complaints according to NHTSA database. These complaints are organized by component to help identify common issues.

What are the most common problems with 2020 BMW M340i?

The most common problems reported for the 2020 BMW M340i are organized by component above. Each component section shows owner-reported issues, crash reports, and fire incidents to help identify patterns and problem areas.

Where does this 2020 BMW M340i problem data come from?

All problem and complaint data for the 2020 BMW M340i comes directly from the National Highway Traffic Safety Administration (NHTSA) database. These are real complaints submitted by actual vehicle owners.