BMW Repair: 1997 bmw m3, bmw m3, oil service

Question
Hi, I am original owner of 1997 m3 sedan. car has 120,000 & always had mobil 1 change @ 5,000 mi, how common is vanos unit replacement & how do you know its bad ,thanks john

Answer
It is very common for vanos unit to go bad, especially on that year M3.  I would recommend using a can of seafoam in your oil 100 miles before your next oil service.  This should take care of the noise your hearing from your vanos unit.  If not, you will need to replace your unit.