2.5 tdi Whine at low revs

**Chriseybaby** · 01-03-2013,11:12 PM

My a6 has an annoying whine from almost tick over up to 1500rpm. I suspected the turbo since it makes a siron sound if you up and down the revs however over 1500 rpm it doesn't make it any more.

any ideas what could cause this?

**adamss24** · 01-03-2013,11:22 PM

Could be a dry bearing, the v6 has a few of them rollers...

**Chriseybaby** · 04-03-2013,09:04 PM

Ive take a video to see if it helps, what do you mean by roller?

**Peter D** · 05-03-2013,12:07 PM

I would say it is one of the belt tensioners Either A/C Power steering of the Aux belt itself, possibly the alternator, you will need to listen around with a stethoscope. It could be the Toothed belt tensioner. Regards Peter

**Chriseybaby** · 05-03-2013,12:44 PM

Thanks, it did have a new power steering belt and tensioner last year because a tensioner bolt snapped. I'll get someone to gently rev it and have a listen to the belts.

Cheers

**ametlib** · 05-03-2013,07:44 PM

For my old eares it sounds like this whine keep up its rpm long after the engine is back to idle. The only two things that does that is the alternator ( (freewheeling) and ofcourse the turbo.....

**bagpipingandy** · 05-03-2013,08:42 PM

I had a whine similar which changed with engine revs, ended up it was an idler roller for the serpentine belt, when ever I removed the belt cover the noise was trebled, In my case i think it wasnt helped due the the tensioner pivot bearing being worn which causes it to not pull the belt square on the roller. your going to have to try and trace the noise location somehow, takes peter D's advice on thestethescope, or a hose on the end of your ear to help stick it where you cannot reach.

regards

Andy

**adamss24** · 05-03-2013,09:34 PM

No freewheel/clutch pulley on the aternator on v6 tdi...

**ametlib** · 06-03-2013,01:00 AM

Wasn't paying attention to the engine type, just listening to the lovely sound of a alternator/ freewheel bearing or a turbo with a leak or a short time to live....

**Chriseybaby** · 06-03-2013,08:41 AM

Well I tried to get my wife to sit in the car and rev it a little, but she wasn't much help. I'm fairly sure it wasn't coming from the turbo, but will get my dad to give me in hand when I next see him. It does need a new cambelt soonish (would these bearings be replaced at the same time?) and I have seen I can get a refurbished turbo for just under £300 or I could cut my loses and buy a different car with different problems.