TeutonicB6

My local german repair shop could not work out this noise... it is not the accessory belt or tensioner as I just replaced both with OEM parts. The noise seems to be coming from the back of the engine and starts once the engine is warmed up. When the engine is revved, it seems to go away. I have seen other videos and posts about this 1.8t squeal, but they either have no answer or people say that it is something in the accessory belt area. The car is a 2004 1.8t quattro 6 speed. The clutch being in or out during idle has no effect on the noise.

Please help, any suggestions are appreciated.

Here is a video of my engine:

TeutonicB6

check out these other videos, the one user who posted the video of the Audi 1.8t responded to a comment I left on their video and they also have not been able to sort out the noise, they said it has been happening for over a year but has not disrupted the engine or thrown any codes, but has become more constant, which is the same case for me, only it has not been going on for 1 year...

TeutonicB6

Well, I'm home from school for the holiday and I visited a friend who owns a German repair shop... his guess was that it is a PCV/emissions problem...

TeutonicB6

I thought I would give this a bump since I have replaced the PCV along with some other cracked tubes that are part of the emissions system... and the noise is still there... I spoke with another 1.8t A4 owner who has the same issue, he said he had most of his emissions system replace at the dealer, but the noise remained... there must be someone out there who knows the cause of this problem... please help!

lyleswk

Just thinking out loud...

1) It could be a PCV leak, but if you have checked all the hoses and valves and found nothing obvious, probably not that. And, it does sound like rotating machinery...

2) Which leads to the next thought; 2 of the rotating bits back there are the bearings that the cams rides on. Never heard of these bearing being noisy, but...

3) And finally, the cam tensioner could be the culprit. It usually just "clatters", but maybe you have one that is noisy before the clatter.

Just throwing some ideas out.

a44me2

Any loss of coolant or power steering fluid? Sponginess in the brakes?

TeutonicB6

No...but the engine does need to warm up before the noise starts, so....

TeutonicB6

I appreciate your response...

the emissions system is fairly large... so i suppose that there could be a faulty piece that remains, but since one guy that told me the dealer replaced his entire system and it didn't stop the noise, I'm thinking that its probably not the emissions system

The cam tensioner was mentioned as a possible culprit by my mechanic (along with several other things), but he couldn't say for sure, although the cam tensioner was at the top of the list... and I can't really afford to start getting into internal stuff right now (I'm about to graduate and move to Colorado for a job), especially since it's not a sure fix... the guy who had the emission work done at the dealer said that his 1.8 has been making that noise for about 3 years, so I feel like if it were something internal, it would have failed within that amount of time, but I suppose you never know...