Hello all, I recently acquired a great S8 from an Audi guru near Atlanta. After a complete timing belt and water pump service and new cam chain tensioners, the car is a fantastic driver, but I keep hearing front end accessory noise that i can't seem to find. It appears to be coming from the passenger side front of the engine compartment. I have run it by some experts, one with a stethoscope! and he guessed it was the fan bearing. So I replaced that and the noise persisted. Second guess was the drive belt tensioner pulley, so I replaced that to no effect. So I ask if there is a known issue or where the sound may be coming from. To me, it sounds like a groaning power steering pump, but that is not making noise or extra noise when turning. So any advice would be welcome. Thank you.

 

I have a similar noise. I think it's the alternator. I thought it may be the accessory belt idler pulleys but I injected grease into the sealed bearings when I had it apart for chain tensioner replacements back in July. Noise still persists.

 

Thanks again for responding! Yes, new alternator fixed the noise!!!