There are 1 owner-reported engine complaints for the 2018 BMW M5in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
The coolant tank on my 2018 M5 failed causing a coolant leak. This is a highly documented problem on the forums and mine needed replacement at 22k miles. The bigger issue is the location of the tank because the coolant leaks on the ignition coils and fuel injectors causing failures later. My coils and spark plugs needed replacement along with the tank. This is unacceptable and BMW needs to address this issue.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 26, 2026