Owners have filed 39 complaints
about the 2018 BMW 330I with NHTSA between 2018 and 2026.
The largest single group is the engine & cooling.
Across this model's run it ranks 9 of 11 worst.
The letter says how bad. This says what kind — whether this year drew
an unusual number of complaints, unusually dangerous
ones, or failures that arrived unusually early.
The dashed ring is 50 — the national norm. Further out is worse.
Complaint volume — 20
Against the median year of the BMW 330I. 50 means typical for this
model; 100 means roughly double.
Severity — 66
12.8% of these complaints
involved a crash, fire, injury or death, against a national rate of
9.7%.
Early failure — 76
44% of failures with a mileage on record happened under
36,000 miles, against a national rate of
29%.
Odometer readings owners gave when they filed. About half of all
complaints include one.
Under 1,000 miles
222.2%
1,000 – 9,999 miles
111.1%
10,000 – 24,999 miles
111.1%
25,000 – 49,999 miles
222.2%
50,000 – 74,999 miles
222.2%
75,000 – 99,999 miles
111.1%
When owners complained
A spike years after the car went on sale usually means a part wearing
out on schedule across the whole fleet — the kind of pattern no single
owner can see from inside their own car.
Jul 2018peak 3Mar 2026
NHTSA investigations into the 2018 BMW 330I
An investigation is the step before a recall: the agency has seen enough
complaints to look into a pattern itself. An open one means it thinks
something may be wrong and nothing has been fixed yet.
From 2000 through 2017, Takata produced millions of air bag inflators using two types of phase-stabilized ammonium nitrate ("PSAN") propellant -- propellant 2004 and propellant 2004L. After prolonged exposure to high temperature cycles and humidity, inflators using propellant 2004 can degrade, causing the propellant to burn too quickly when ignited. The rapid burning can cause the inflator to rupture during deployment, potentially causing serious or even fatal injury to vehicle occupants. See 2016 Blomquist Report at www.nhtsa.gov/sites/nhtsa.gov/files/documents/expert_report-hrblomquist.pdf.C...
Complaints that involved harm
Reports where the owner recorded a crash, a fire, an injury or a death.
Portsmouth, VAFire
ELECTRICAL SYSTEM
While driving on the highway, my vehicle unexpectedly caught fire due to no fault of my own. Upon investigation, it appears the fire originated from a short in the rear window defroster wiring, which led to significant damage in the right rear C-pillar area, headliner, rear window, and rear deck. This event was not only hazardous to my physical safety but also deeply traumatic on a personal level. As someone who suffered severe burns as a child, experiencing a fire while operating a vehicle triggered a powerful emotional response. The trauma of the incident has had a profound impact on my mental health and sense of safety. I have always trusted BMW for its engineering excellence and commitment to safety, which makes this situation even more disheartening because they refuse to fix my vehicle.
NHTSA complaint #11678001 — an unverified report by a vehicle owner.
Chesapeake, VAFire1 injured
ELECTRICAL SYSTEM
I smelt and saw smoke coming from the back of my vehicle. I pulled over on to the left side of [XXX] bound. Then, I jumped out of the car to check the truck. I didn't see anything, then i popped the hood and still did not see anything visible. I then went back to the trunk to check it again, and that is when I saw flames pop out from the back seat area. It was in the area where the back de-frost wires and some other wires are as well. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11667410 — an unverified report by a vehicle owner.
Scotch Plains, NJFire
ENGINE
On January 19, 2022 I was driving and then smoked filled inside my car and the outside engine was smoking and a light came on that said check coolant. BMW service took me in that day and they said my coolant broke. They removed it and replaced it. They did not understand how the coolant broke but I paid for the service and parts and moved forward. On November 25, 2022 I went into the same BMW service center to get a routine car service and they stated there was a recall and they would replace my coolant for free. (After I told them I paid for it ($699.63) . They insisted I replace it for free again and reach out to BMW corporate for a reimbursement of previous service. I received a call yesterday stating they would not replace it and reach out and file a report with NHTA.
NHTSA complaint #11497221 — an unverified report by a vehicle owner.
Scotch Plains, NJFire
FUEL/PROPULSION SYSTEM
On January 19, 2022 I was driving and then smoked filled inside my car and the outside engine was smoking and a light came on that said check coolant. BMW service took me in that day and they said my coolant broke. They removed it and replaced it. They did not understand how the coolant broke but I paid for the service and parts and moved forward. On November 25, 2022 I went into the same BMW service center to get a routine car service and they stated there was a recall and they would replace my coolant for free. (After I told them I paid for it ($699.63) . They insisted I replace it for free again and reach out to BMW corporate for a reimbursement of previous service. I received a call yesterday stating they would not replace it and reach out and file a report with NHTA.
NHTSA complaint #11497221 — an unverified report by a vehicle owner.
The most recent complaints
In the owners' own words, exactly as filed with NHTSA.
at 40,000 milesDumont, NJ
ENGINE AND ENGINE COOLING
The contact owns a 2018 BMW 330I. The contact stated that while driving at an undisclosed speed, unknown warning lights were suddenly illuminated, indicating that the engine was overheating. The message instructed the driver to shut off the vehicle immediately. The contact pulled over and turned off the vehicle, and it was discovered that the coolant reservoir was empty. The vehicle was towed to a local dealer, where it was determined that there was a plastic part from the oil cooler housing that needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 40,000.
NHTSA complaint #11728250 — an unverified report by a vehicle owner.
Alexandria, KY
ENGINE
The engine overheated and suddenly lost power/ acceleration while driving in rush hour traffic at highway speed. I had to move across 3 lanes of traffic to get on to shoulder of highway safely while car and engine sputtered and slowed to a stop with no power or acceleration. After having vehicle towed I was told by certified technicians that the oil filter housing was made of plastic with coolant lines inside and failed causing rapid coolant loss with no low coolant warning and ultimately loss of engine and power.
NHTSA complaint #11728378 — an unverified report by a vehicle owner.
Walkertown, NC
UNKNOWN OR OTHER
The coolant system and oil housing filters. The entire coolant system components fails in this vehicle after 60,000 mile due to the parts not being all aluminum. This fix alone is about 8k from the BMW Dealership. This isn’t fair to the customer! This needs to be a recall! The parts needs to be more stronger and never replaced with the same manufacturer part! This fails the entire engine system! The car will have multiple issues just because of this constant failing area of the vehicle!
NHTSA complaint #11715764 — an unverified report by a vehicle owner.
Walkertown, NC
ENGINE
The coolant system and oil housing filters. The entire coolant system components fails in this vehicle after 60,000 mile due to the parts not being all aluminum. This fix alone is about 8k from the BMW Dealership. This isn’t fair to the customer! This needs to be a recall! The parts needs to be more stronger and never replaced with the same manufacturer part! This fails the entire engine system! The car will have multiple issues just because of this constant failing area of the vehicle!
NHTSA complaint #11715764 — an unverified report by a vehicle owner.
at 80,000 milesJonesboro, GA
ENGINE AND ENGINE COOLING
The contact owns a 2018 BMW 330I. The contact stated that while driving 35-40 MPH, the vehicle shut off unintendedly. The contact stated that there was an oil intake leak and a coolant leak. There were several warning lights illuminated after the failure. The vehicle was towed to an independent mechanic, who determined that there was an engine malfunction with the vehicle. The local dealer was contacted and confirmed there was no recall or warranty coverage on the VIN for the failure. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 80,000.
NHTSA complaint #11688157 — an unverified report by a vehicle owner.
Brooklyn, NY
ENGINE
Car keeps overheating. Water pump, water hose and expansion tank have been replaced several times and the car still overheats.
NHTSA complaint #11680483 — an unverified report by a vehicle owner.
Portsmouth, VAFire
ELECTRICAL SYSTEM
While driving on the highway, my vehicle unexpectedly caught fire due to no fault of my own. Upon investigation, it appears the fire originated from a short in the rear window defroster wiring, which led to significant damage in the right rear C-pillar area, headliner, rear window, and rear deck. This event was not only hazardous to my physical safety but also deeply traumatic on a personal level. As someone who suffered severe burns as a child, experiencing a fire while operating a vehicle triggered a powerful emotional response. The trauma of the incident has had a profound impact on my mental health and sense of safety. I have always trusted BMW for its engineering excellence and commitment to safety, which makes this situation even more disheartening because they refuse to fix my vehicle.
NHTSA complaint #11678001 — an unverified report by a vehicle owner.
Chesapeake, VAFire1 injured
ELECTRICAL SYSTEM
I smelt and saw smoke coming from the back of my vehicle. I pulled over on to the left side of [XXX] bound. Then, I jumped out of the car to check the truck. I didn't see anything, then i popped the hood and still did not see anything visible. I then went back to the trunk to check it again, and that is when I saw flames pop out from the back seat area. It was in the area where the back de-frost wires and some other wires are as well. Thank you, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
NHTSA complaint #11667410 — an unverified report by a vehicle owner.
Brea, CA
UNKNOWN OR OTHER
My 330i 2018 bmw has a cracked in the oil housing unit. This is due to bmw putting plastic parts instead of aluminum. After researching this I found thousand of people complaining about the sane thing. The car overheats and sometimes the oil gets mixed into the coolsnt system b causes more damage. This seems to happen on cars with mileage between 60-70 on engines B46, B48 n B58z
NHTSA complaint #11655822 — an unverified report by a vehicle owner.
Brea, CA
ENGINE
My 330i 2018 bmw has a cracked in the oil housing unit. This is due to bmw putting plastic parts instead of aluminum. After researching this I found thousand of people complaining about the sane thing. The car overheats and sometimes the oil gets mixed into the coolsnt system b causes more damage. This seems to happen on cars with mileage between 60-70 on engines B46, B48 n B58z
NHTSA complaint #11655822 — an unverified report by a vehicle owner.
Carmel, NY
ENGINE
Oil Filter Housing failed and coolant gushes all out which makes the car undrivable and risk of engine overheating and failure.
NHTSA complaint #11646108 — an unverified report by a vehicle owner.
at 60,150 milesAldan, PA
FUEL SYSTEM, DIESEL
The contact owns a 2018 BMW 330I. The contact stated that while driving at various speeds, the engine overheating message was displayed on the instrument panel with the temperature gauge rising to hot(H). The vehicle was taken to an independent mechanic where the coolant reservoir was topped off however, the failure persisted. The contact then received notification of NHTSA Campaign Number: 21V907000 (Fuel System, Diesel) which was linked to the failure. The vehicle was taken to the dealer where the recall repair was performed. The contact stated that recently the vehicle began to leak coolant. The vehicle was taken back to the dealer and the contact was informed that the manifold needed to be taken off to perform a diagnostic test. The contact was informed that the oil filter housing unit and the water pump both needed to be replaced. The manufacturer was notified of the failure and transferred the contact to the NHTSA Hotline to report the failure. The vehicle remained in the possession of the dealer unrepaired. The failure mileage was approximately 60,150.
NHTSA complaint #11641715 — an unverified report by a vehicle owner.
Niskayuna, NY
ENGINE
The vehicle gave a warning that the engine coolant was low and to power down before it overheated. Upon taking it to the dealer, it was discovered that the oil housing unit was defective. After doing online research, this is a very common issue with this part. I had a previous vehicle with a similar issue that caused the vehicle to shut down in traffic from overheating.
NHTSA complaint #11636332 — an unverified report by a vehicle owner.
North Ridgeville, OH
ENGINE
On 12/03/2024, while traveling at approximately 35mph, the "top off coolant" light came on. After traveling for approximately 10 more minutes, in route to get coolant, a warning message came on the screen advising to drive cautiously to prevent engine scorching. The vehicle then began to slightly lose power while traveling on a busy road. The vehicle was then shut down and towed to BMW dealership. During the tow, it was discovered that coolant was leaking from the center area of the engine block. The manufacturers dealership service rep advised that the technicians discovered that the oil filter housing needed to be replaced. They also found that the coolant pump also needed to be replaced. The rep advised that the coolant seal on the oil filter housing had worn down and caused the coolant leak. He also advised that the coolant pump needed to be replaced, as it was also leaking. It was later discovered because the valve that the pressure propelled, hot coolant flows through in the oil filter housing is made of plastic, it often wears down and coolant leaks out heavily. The water pump is also effected by the part manufacturing issue. In addition to receiving a $4,270.42 invoice for repairs today, we just recently purchased the $199.00 BMW Vehicle Check Service from the dealership on 9/23/2024. At that time, we were advised there were no issues with the vehicle. We have sense learned that there have been multiple recalls on various BMW models for this exact same issue. However, the VIN on my vehicle has not yet been identified for recall. Had this issue gone on for mere moments more, the engine could have caught fire, and or, a catastrophic crash could have ensued, effecting any driver on the road.
NHTSA complaint #11628725 — an unverified report by a vehicle owner.
Brooklyn, NY
FUEL/PROPULSION SYSTEM
Coolant fluid exits from the expansion tank into the overflow leaving no fluid in the expansion tank. Then it causes and overflow/steam to burst out of the overflow tank. Then the coolant is low notification comes on which warrants to replace the coolant fluid. Took it to a few BMW dealers. They've did a flush, replace expansion tank, and water pump, also tested the pressure several times at 2 different BMW dealerships. I leave the dealership broker and with the same problem starting again within that week. This has been a constant issue which never seems to be fixed by any BMW dealer.
NHTSA complaint #11626777 — an unverified report by a vehicle owner.
Baldwin, NY
UNKNOWN OR OTHER
Car coolant is leaking due to a bad plastic coolant vent line. I had this issue in January 2023 where it was covered under a recall. I tried contacting the bmw dealership who fixed this recall and they stated there was no current recall. Although is the same issue again.
NHTSA complaint #11608828 — an unverified report by a vehicle owner.
Atlanta, GA
FUEL/PROPULSION SYSTEM
My 2018 BMW 330i has the same problem that the recall for the fuel sensor level on 2018 BMW M5! I broke down on the side of the interstate and had it towed to BMW and they said it was the fuel sensor reading more than it should and wanted to charge almost 3,000 to fix it. There are similarities to the other recalls and my vehicle should also be included in that recall. I had to pay 300.00 just for them looking at it. I found it odd the sensor would do that and my investigation has brought me here. There was no warning and I was stranded on the interstate
NHTSA complaint #11587129 — an unverified report by a vehicle owner.
Orlando, FL
POWER TRAIN
Multiple codes came on right after I had gotten my thermostat and my water pump fixed. However it ended up being that there was more leaks throughout the rest of the car. The car has currently cost me $3400 to fix and it’s still not fixed because nobody can figure out where the actual leak is coming from. The coolant is leaking and nobody can figure out where, it’s been having jerking issues since it started leaking and I read on other Bmw’s that the coolant leaks into the head gasket, causing the engine to blow
NHTSA complaint #11569599 — an unverified report by a vehicle owner.
Orlando, FL
UNKNOWN OR OTHER
Multiple codes came on right after I had gotten my thermostat and my water pump fixed. However it ended up being that there was more leaks throughout the rest of the car. The car has currently cost me $3400 to fix and it’s still not fixed because nobody can figure out where the actual leak is coming from. The coolant is leaking and nobody can figure out where, it’s been having jerking issues since it started leaking and I read on other Bmw’s that the coolant leaks into the head gasket, causing the engine to blow
NHTSA complaint #11569599 — an unverified report by a vehicle owner.
Orlando, FL
ENGINE
Multiple codes came on right after I had gotten my thermostat and my water pump fixed. However it ended up being that there was more leaks throughout the rest of the car. The car has currently cost me $3400 to fix and it’s still not fixed because nobody can figure out where the actual leak is coming from. The coolant is leaking and nobody can figure out where, it’s been having jerking issues since it started leaking and I read on other Bmw’s that the coolant leaks into the head gasket, causing the engine to blow
NHTSA complaint #11569599 — an unverified report by a vehicle owner.
Trumbull, CT
ENGINE
At around 65k miles multiple plastic engine coolant connectors and hoses crack and fail. 5 locations at the same time! Coolant pump leaks. I went to an independent repair shop for a second opinion and repairs for $2,400 so far. Cheaper than the BMW service department. There was a recall done 2 years ago for 1 hose I believe. The entire cooling system should be recalled. We could be stranded somewhere in a bad situation and the engine could be destroyed if overheated. Awful and bad design.
NHTSA complaint #11565602 — an unverified report by a vehicle owner.
The contact owned a 2018 BMW 330I. The vehicle was taken to a local dealer for a Manufacturers Recall: 0017150200 related to the Coolant Leak to be completed. The contact stated that after driving 7 miles to her home at 35 MPH, there was smoke coming from the engine compartment. All the warning lights illuminated. The vehicle was powered off and the smoke extinguished on its own. A fire report was not filed. There were no visible flames. The local dealer was called and the vehicle was towed back to the dealer where it was confirmed that the pressure test was not completed and there was no coolant in the vehicle. The dealer informed the caller that the struts needed to be replaced however the coolant failure was repaired. The vehicle was repaired for the coolant failure however the contact mentioned that the vehicle was not performing as designed. The manufacturer was not notified of the failure. The failure mileage was 51,086.
NHTSA complaint #11563082 — an unverified report by a vehicle owner.
Saratoga Springs, UT
ENGINE
My oil filter housing failed at about 53,000 miles. While driving to work I got a low coolant warning and pulled over to see coolant dumping out of my car. The low coolant warning only comes on when the expansion tank is almost completely empty which can lead to oil and coolant mixing and overheating which will lead to premature engine damage without any early warning signs. I’ve read through forums and everyone on there has their oil filter housing fail at the same time, (around 50-60k miles). This is a huge issue in the community and BMW wants to charge almost 3,500 to replace it with their “revised part”. The housing has been revised 3 times now and so the manufacturer should replace these failed designs with the new revised ones. There’s already been a recall on the B48 engine for the plastic cooling line that leads into the head of the engine and it looks like the oil filter housing is the next biggest common failure. I tried to upload a screenshot from the service center at BMW with the quote and failure but it’s not working on my mobile.
NHTSA complaint #11562328 — an unverified report by a vehicle owner.
Lake Oswego, OR
SEAT BELTS
CUSTOMER REAR PASSENGER SETBELT DOESNT LATCH
NHTSA complaint #11504837 — an unverified report by a vehicle owner.
Topeka, KS
VEHICLE SPEED CONTROL
The car's cruise control's rocker switch got stuck causing the vehicle's speed to increase continually. The rocker switch allows driver to increase or decrease speed when the cruise control is activated. The rocker switch permits speed increase in increments of 1 mph or 5 mph. If pressed up until a resistance point, the speed increases by 1 mph; if pressed beyond the resistance point, it increases by 5 mph. In my instance, I was on cruise control at 61 mph (in a 55 zone, where traffic was also moving in the 60's). I wanted to increase speed by 3-4 mph using the rocker switch to safely complete an overtake. However, the rocker switch got stuck and caused the car's peed to increase past 80mph. I almost missed hitting the car ahead of me.
NHTSA complaint #11502140 — an unverified report by a vehicle owner.