Premature failures are being caused by a fault on a BMW model, triggered by its power-assisted steering (PAS) pump pulley or auxiliary belt coming into contact with the sub frame when being driven over speed humps, Autoelectro has warned technicians.

The contact between the components, on the BMW 3.0 petrol E90,92 and 93 Series 335i (2008-onwards), can cause the auxiliary drive belt to stretch, break or even snap.

Consequently, the damage can result in the premature failure of the alternator pulley and its bearings, as well as the PAS pump pulley.

When tasked with working on the vehicle, technicians should inspect and replace all the components mentioned, as well as the LH engine mounting, if necessary, before fitting a replacement alternator.

Failure to do so will mean the fault is likely to reoccur and the alternator will stop working.

The alternator will not be covered under Autoelectro’s warranty due to misdiagnosis and incorrect fitting procedures.

*Original article can be found in Garage Wire Magazine and on their website at: