A new noise...

Pinkythelabrat

A2OC Donor
Hi all.

I hate funny noises in mechanical things! They wind me up because they are very hard for me to quantify and that sucks!

Most of my visits to various Audi 'specialist' garages during my first few years of A2 ownership were to try and sort out the various funny noises. Actually, none of these visits helped and it was a combination of reading topics on here and some of the members (Mr Broons, Murdo and Tom - thanks ) who put me on the right track to sorting out most of these noises. (The Webasto noise almost had me replacing the whole Aircon system until James pointed out the cause!)

A long winded way of saying 'I hate odd noises' and 'Viva la A2OC!'

Anyway, to the point. I just had my cam belt, tensioner and water pump replaced and since then I have an irritating noise whenever my revs drop below 1000. It goes as soon as I press the accelerator and returns if I dip for the briefest instant below 1000 - even changing gear. It MAY only appear once the engine is warm but it's too early to say as it's been pretty warm recently here so this is just a 'possible' for now.

I can't describe noises well (hence my hatred of them) mostly because of my tin ear so I'm hoping someone might be able to give me some ideas of what it might be so I can start narrowing it down. 'Annoying' isn't very diagnostic. Higher pitched than normal idle noise is about the best I've got. I also haven't been able to localise the source yet.

My alternator is only 6 months old so I didn't think it could be this but I'm willing to hear any suggestions to the contrary.

Thanks all.

Alex.
 
Oh, and my idle never seems to go below 900 and my temp never goes above 70. If that helps at all.

It's a 2002 TDi75 since I forgot to mention that as well.


Sent from my iPad using Tapatalk
 
I have similar noise but only under load, even a light one when revs are 1000-1300. high pitched noise, either something rotating touching somewhere or more likely IMO, the exhaust gasket leak.

Boris
 
The alternator belt and pulley are always candidates for this sort of noise. On most there is a clutch pulley which can act up before failing.
Normally characterised by a screaching that can come and go as the revs vary. The clutch can fail by either seizing so it acts like a sold pulley (the alternator does not like this) or it fails by slipping when under load. Noise from the pulley or belt is the best diagnosis as a hand check on the pulley clutch action can appear to show no problem when there is one.
Have a listen with the bonnet off and see if the noise is coming from the area of the auxiluary belt.

Geoff
 
Last edited:
Without any knowledge of the tdi engines, it could be a slightly tight cambelt - but only really possible if the tensioner is manual - seeing as your cambelt, tensioner and waterpump have just been changed!

Nick
 
Thanks all. I'll try to put my head in the engine bay to narrow it down by location a bit more.

I was kind of hoping someone would just know an obvious cause. I got lucky last time!


Sent from my iPad using Tapatalk
 
I put my head in the engine bay today... not depressed, just trying to track down this noise.

It definitely seems to be from the side of the engine, most noticeable with my ear above the alternator and all the belts. Not really a surprise. I can't get more specific because it's pretty noisy in there!

I don't recall my engine and the pipes vibrating quite that much in the past either.

Anyway, the noise is a bit like a trapped hamster wheel/guinea pig choir/asthmatic cyborg kind of noise...

Anything I can try to be a bit more diagnostic before I front up at the garage that replaced the cam belt and imperiously stamp my foot while pointing at the car?


Sent from my iPad using Tapatalk
 
Back
Top