Low Rev Rattle From an 8L S3 When Hot

[supreme]

Hi

I have a 2000 8L S3 with a pretty standard APY lump having covered 94K.

A month or so ago it started rattling between 1200 and 2000rpm only when warmed up and gets louder when the car was nice and hot, the rattle seems to come from the left of the head but doesnt do it all of the time when its hot.

So far I have had the rocker and cam covers off and nothing seems to show any signs of wear. I was suprised at how good the internals of the head were, the cam chain is under tension and the guide only has a small groove, so I think that can be ruled out.

I have changed the oil pump and pick up and replaced the oil with Synta for piece of mind, as I thought it could be down to low oil pressure but this hasn't solved it.

The serpentine belt and cam belt are both under tension and seated correctly and do not seem worn in any way that would indicate that they were the problem. Changing these and the water pump will be my next job

Anyone have anything else I can check, the rattle totally vanishes under 1200rpm and above 2000rpm, I'm stumped as is my friend who is a mechanic.

Thanks in advance

Alex

 

[wibble111]

My money's on the cam chain tensioner. IIRC its a main dealer part and make sure you are pre-lubed if and when you buy one. Mine has the cam chain rattle, has done since i got it, 3 years & 25K later it still doing it and hasnt made a blind bit of diffrence to the car.

 

[supreme]

Cheers for the response, I hope I can find a method of curing it as the car draws peoples attention but for the wrong reasons!

 

[<tuffty/>]

If its an APY engine code then it will be non VVT and a lot cheaper... VVT tensioners are well expensive... AMK/BAM are VVT...

Sounds like a tensioner rattle from what you describe..

<tuffty/>

 

[supreme]

Again, thanks for the response. I'm a firm beliver of upgrading rather than replacing. Therefore I think I may put up with it for now and put the money into building up a worked AEB head.

 

[jc_1989]

I have this exact same problem, its doing my head in!! Does yours hav a 'dry chain' type-rattle on start up as well?

 

[supreme]

No, its a little tappetty on tick over but thats it, no other noises just this one at those revs.

Really annoying as I have car looking fairly respectable but it sounds awful unless you boot it!

 

[Robbo1144]

sounds like the bottom end bearings to me.
had to change them on a TT 225 the other week, it had the same symptoms. if you take off your sump and use a large flat head screwdriver, give the rods a push around, there should be no up and down movement. also check the oil for stuff that looks like bits of gold leaf

Robbo