BMW Alternator Replacement needed if the Battery light comes on?

You could imagine that at a BMW repair shop here in Naperville like Fluid MotorUnion would see vehicle problems ranging from the mundane to the really wild, as well as everything in between. With the wide range of vehicles we service and diagnosis, you can say on a typical day it would take a lot to surprise us. This BMW E39 528i isn’t exactly known for its robust alternators. 100k miles is really the upper end of service life on them. What’s unusual about today’s blog feature is just how long it lasted before this BMW Alternator Replacement was necessary.

1998 E39 528i BMW Alternator Replacement dead battery light not charging dies out air duct cooling m52 m52tu m54 6 cylinder

The BMW Alternator Replacement job on a E39 528i is straightforward for the most part. Here is what it looks like when removed. If there are a large number of miles on the vehicle then this job could be a bit tricky.

This customer came in with a 1998 E39 528i with the M52 single Vanos engine. His complaint was that the battery light was on, and he had to jump it to get it to the shop. A test of the charging system showed 12.6 volts, not close enough to the 14 volts needed to supply the vehicle. It was obvious after we performed a load test that the system was dead, and a BMW Alternator Replacement was needed. While an alternator failure is not uncommon on the E39 chassis 5 series, this one gave us a bit of a shock when we finally got it removed. The duct used to supply air to keep the alternator cool had become completely packed with leaves, dirt, and rocks. While it is within the realm of possibility that this tube could become clogged, the crazy part was how long the alternator lasted like this. The tube didn’t become clogged like this overnight, no this was a result of years of driving. And with over 238000 miles on the clock, it was inconceivable that this was the original alternator for the vehicle!

1998 E39 528i BMW Alternator Replacement failure dead battery light not charging dies out new and old alternator leaves clogged rear cover off air duct

This BMW Alternator Replacement was necessitated by the build-up fo debris in the cooling duct. Lack of airflow from a clogged passageway is usually a recipe for fast failure.

1998 E39 528i BMW alternator replacement failure dead battery light not charging dies out new and old alternator leaves clogged dirt mud rocks

Needless to say, this customer got his money’s worth out of his original before it needed a BMW alternator replacement!

1998 BMW E39 528i alternator failure dead battery light not charging dies out comparison of new and old alternator leaves clogged

The need for this BMW Alternator Replacement is pretty obvious when you compare the new and old parts! Is your battery light on? Having a hard time starting your vehicle? You may need to have your charging system checked and it might be time for a BMW Alternator Replacement. So don’t wait and get stranded, call us at 630-305-3054, or contact us through email at We’re conveniently located just minutes off of the I-88 exit in Naperville, in the Chicago Metropolitan suburbs.