Dodgy running on startup

[bantam1]

As per title for the last week on startup the car (2000 S3) is fine for a few secs and then bouncing idle (up down, up down almost as if it might cut out - only way to describe it) until I give it some revs and then it's OK. Fine in general driving and idling in traffic and won't do it again if engine switched on and off, only after it cools for a while.

Any ideas?

Cheers in advance.

 

[Crashlanding]

hi my A3 was the same, i changed the spark pugs and its so much smoother now. try it!

 

[AndyMac]

Temp sender usually the main culprit

 

[themanthatcan]

MAF, Spark Plugs, Fuel Pump Relay and CTS are the possible causes I have listed for this problem.

 

[MikeA3]

Do you have access to vag.com? - It would really be best to get the car scanned so you know exactly what's causing the problem and probably save you cash as well

If you don't have vag.com, I've put together a list of other owners who are willing to help people out, have a look here and try to find someone local to you.

http://www.audi-sport.net/vb/showthread.php?t=57293

Mike

 

[Wingnut Express]

I've got a similar problem, where it takes about three minutes before I drive the car without it hesitating & sounding like it's running on three cylinders. I've done the usual Plugs, Temp Sensor & Coilpacks, but sadly it is the Cam Chain Tensioner. If you can get it on a Vag Com that should help to narrow down the possibilties thou I do believe the plugs and Coilpacks come under the same fault code, thou I maybe wrong. Good luck and I hope it's not to pricey.

 

[bantam1]

I've got a similar problem, where it takes about three minutes before I drive the car without it hesitating & sounding like it's running on three cylinders. I've done the usual Plugs, Temp Sensor & Coilpacks, but sadly it is the Cam Chain Tensioner. If you can get it on a Vag Com that should help to narrow down the possibilties thou I do believe the plugs and Coilpacks come under the same fault code, thou I maybe wrong. Good luck and I hope it's not to pricey.

Would a problem with the cam chain tensioner be audible? I only say this as I thought I was being paranoid about a new noise from the engine over the last couple of months - very hard to describe but like a ticking (i.e. mechanical noise) after I let off the revs mainly at between 25-40 MPH. Could these be related?

Car is nearly due second Cambelt service (over 124K) - is cam chain tensioner included in this (sorry mechanically naive!).

Thanks for the responses guys.

Oh P.S. temp sender recently replaced and spark plugs not that old.

 

[themanthatcan]

Yeah the cam chain tensioner can make a ticking noise. The car sounds very much like a diesel. Have a listen on the right-hand side of the engine block for a ticking sound.

The cam chain tensioner isn't part of a service schedule unfortunately, it's on the opposite side of the engine to the cam belt.. If it is playing up then you're looking at at least £500 to replace it as the part is really expensive. I had mine done recently and luckily it was covered under warranty.

I'd recommend getting your car plugged into VAG-Com as you'll usually get a 16395 or a 16396 error if the tensioner is playing up. I also got a CEL on the dashboard after a while.

 

[voorhees]

seems to be a common problem I had the same on cold start up but also had loss of boost,paid about five hundred quid for plugs,coilpacks,maf replaced and throttle body cleaned and re-adapted,inlet manifold removed and pipes replaced...boost problem solved but still has a misfire on start up every now and again
Vag-com showed jack and the stealers wanted to replace my ECU

 

[bantam1]

Thanks gang - will let you know how this goes.

 

[Aky]

I've also changed the main culprits. I haven't cleaned the TB and haven't really looked for any split pipes. I think me and voorhees had the same symptons. I haven't bothered sorting mine out as it only does it when really cold and to be honest I'd forgotten about it. especially as it should be going soon.

 

[bantam1]

OK - so might be something common and can't hear unusual noise from right side of engine block so hopefully not cam chain tensioner.

P.S. how often do people change their MAFs. Mines been on for about 3 years now (noticed improvement in running and throttle response then) so is it time to change? Car has felt a bit 'dull' at times and average MPG on DIS has gone up .2 recently after not moving for yonkers. Might this indicate underperforming MAF with other symptoms?

Will get this checked out but thought I'd exclude most obvious first.

 

[Ibzzzzz]

Cam Tensioner is pretty easy to replace. Had to do mine when the valves went, but getting to it was the problem.

 

[Ibzzzzz]

But if im honest the 20v engine is crap should of had DOHC and VVT instead of the belt cam to chain to exhaust cam.

 

[Wicked666]

I've developed a similar problem - when idling, car sometimes feels like it's going to stall. When I pull away, there's no power until it revs over 2k and then it's ok.

Been using vag com a few times and it shows nothing - does that mean the spark plugs and coil packs are ok?

Would a dodgy cam belt tensioner show up on vag com? I had it replaced 40k miles ago. Would this cause the problem described? I'm sure all the pipes are ok.