Common issues & diagnosis
Alternators are an issue in most BMWs. The main problem with them is the bearings—which wear out and make a loud grinding or whining noise whilst revving or idling.
Additionally, the voltage regulators are prone to failure—which will usually result in overcharging/undercharging of the battery.
What is the part's function?
The alternator is responsible for charging the battery and powering the vehicle’s electrical systems while the engine runs. It converts mechanical energy from the engine into electrical energy, ensuring that the battery remains charged—and that systems like lighting, infotainment, and climate control have a consistent power supply.
How to determine fitment compatibility
There are always multiple, non-exchangeable types of alternators within any given model generation—this is to account for different engines.
The best way to confirm fitment compatibility of an alternator is to match the BMW part numbers from the catalogue. This can be done by decoding your vehicle’s VIN in a BMW EPC (electronic part catalogue.)
If you don’t have access to an EPC, provide our team with your vehicle’s 17-digit VIN—and we’ll check our stock for a compatible match.
It also possible to determine fitment by matching the part numbers physically on alternators. Either the BMW or manufacturer number can be used—but these number will likely be superseded and you won’t catch other exchangeable versions.
Interchangeability between models
Alternators are highly-interchangeable, particularly between vehicles with alike/similar engines.
