I also put this in the TT section -

I will gladly paypal $100 to the first person who can diagnose my problem. I have no dealer in my side of South Dakota and am desperate. I am good for it, it would be the best $100 I could spend. VW dealer won’t even look at it which makes me mad.

My car, 2001 1.8t Audi TT 225hp, 130k mile, runs rough. Perfect idle, doesn’t waver, but it is just rough. Revs up rough. Very predictable. I can set the cruise at 80mph and it seems to be perfect. Fuel economy seems normal, plugs look good, 300 miles of this and no CEL. Problems came on all it once, not subtle over time. All stock, not a mod car.

Is running on all 4 cylinders

This is very embarrassing, but I will go through what I have done. Try not to laugh too loud.

New front two motor mounts. Made the problem less noticeable but the underlying cause it still there.
New plugs
New ignition coil packs
New MAF
Replaced timing belt
Took cylinder head off, had it rebuilt. Needed valve guides, all 20 were out of spec
As long as I was in there, had turbo city look at the turbo.
All new intake and exhaust gaskets
New cam sensor
Checked vacuum lines. Replaced one on fuel pressure regulator.

Seems to run rougher when cold. When the “warm” circuit kicks in it runs better.

May not be as powerful as it once was, but it has been so long I may have forgot.

Please PM me or email if you have any thoughts or want me to check anything to help you diagnose.

Thanks! I am a desperate man.

Peter S

 

Try doing the SeaFoam treatment.
Good luck.

 

buddy owns Salisburymotorcar.... well respected small dealer here in hickville..... what gaps and brand plugs are you running? He says thus far it;s electrical sounding in nature ....

 

I thought it was electrical as well and looked for a bad ground or loose wire somewhere. I have spent days bent over the hood, can't find a thing.

I almost think there may be a internal vacume leak. Some sort of cold start air valve or something.

still praying for the CEL to come on!

I'll sea foam the throttle body. may get lucky. will feel really stupid if that is the problem, but I already feel pretty stupid!

PS

Peter S

 

pcv tubes/hoses... they get clogged up with **** all the time on the 1.8t's

.... take the engine cover off and take a few hoses/tubes(pcv) apart and feel inside with your finger...

 

I'll try it tonight - PS

 

check your gaps man if the plugs are new they may not be gapped right (just a long shot but what's it hurt)

 

Agreed with Jet, Jet and I worked on an a4 where the oil pickup tube was clogged there are pictures in a different post could be the problem also check all your vacum hoses we found on the same a4 that only had pin sized holes but it did affect how it drove. Just some ideas.

 

By the way a good way to tell is to take the valve cover off and look at the cams if they look dry or whiteish, Then you are defintly not getting enough oil. I am suprised the engine light hasn't tripped. Have you run a vag com on it. i have picked up codes on cars without the engine light being on. it might at least help get you going in the right direction.

 

Throttle body sticking due to hardened oil? Cleaned mine with citrus degreaser. Worked a treat! Good luck!