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EnginePart report

2018 BMW 330I Engine Problems

Complaints
12about this part
Share
38%of 32 total for the year
Median mileage
36,500miles
Trend
Not enough dataFewer than 15 complaints, too few for a reliable trend.

NHTSA recorded 12 complaints about the engine of the 2018 BMW 330I, 38% of the 32 complaints for this model year. Where a mileage was given, the median is 36,500 miles. 1 a fire, according to the filers.

Fewer than 15 complaints name this part, so treat the figures as a rough indication only.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“On the way home from purchasing this vehicle as a cpo at the Bmw dealer, a loud engine knock developed. Made an appointment at the Bmw dealer to check it, and on the way there, it lost power & engine malfunction warning lights illuminated. Had to pull off highway, fearing car would stop running altogether. Diagnosis was failed rod bearings, with lots of metal shavings in the oil filter. Mileage was 36,500 miles.”

NHTSA complaint #11408387, filed 2021-04, 36,500 miles

“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, filed 2025-04

“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, filed 2026-03

“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, filed 2024-01

“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, filed 2024-02

Related service bulletins

Engine: other model years

YearComplaintsShare of year
2025117%
2021828%
20201936%
2019922%
20181238%
20172048%
2006167%
200514%
200212%
200122%

Other parts of the 2018 BMW 330I

Other or unknown
6 complaints
Fuel system
5 complaints
Electrical system
4 complaints
Engine cooling
2 complaints
Vehicle speed control
2 complaints
Brakes
1 complaints
Forward collision avoidance
1 complaints
Seat belts
1 complaints
Steering
1 complaints
Body and structure
1 complaints
Tires
1 complaints
Transmission and drivetrain
1 complaints

← All problems reported for the 2018 BMW 330I

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 27, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology