Sorry if I'm going the wrong way about this, but I'm trying to revive an old thread - it pretty well covers my problem, but doesn't reveal a solution... Any help or advice would be appreciated.

Many thanks... John.  See:-

Cheers.

Have you checked the obvious like changing the spark plugs and making sure they are gapped correctly?

 

These engines are prone for vacuum leaks also, especially from the CCV system under the inlet manifold, I recommend a smoke test or if your cheap like me and you have a compressor with a regulated air supply and some fittings you can use a baked bean tin in the intake and some leak detector spray.

 

Throttle body has been mentioned in that thread which can benefit from a clean and then a throttle body reset may help.

 

Upgrading the engine earth was also a common cure on the 1.8T back when I used to frequent the TT forum

 

Coil pack wiring looms are also prone to degrading on these engines, all the insulation comes off with the heat.

Thanks SuperbTWM - could you let me know a bit more about the smoke test please? I'll check the coil pack looms tomorrow when it's light (weather permitting), the dealer VAG software didn't indicate any coil pack or misfire reports. I'll also check out cleaning the throttle body.

Cheers - John.

Garages have a smoke machine that they hook up to the intake and it makes it pretty easy to see any leaks you may have.

 

These engines are getting on a bit now and with all the oil that gets passed through the crank case vent system it either blocks up completely or the rubber parts perish and you end up with holes everywhere that suck in un-metered air and can effect the running of the engine.

 

Have you had a good look round to see if you can see anything obvious?

 

 

Thanks for the info. I don't have the necessary stuff to easily make a smoke machine, so I'll start with the observations and throttle body. I'll have a good look around this morning in the daylight, and have a go at the throttle body at the weekend. I'll let you know what I find.

Thanks again for all your help - John.

I've had a good look at the hoses etc, and saw something I have never noticed before - behind the washer reservoir, the is a rubber pipe protruding, apparently going nowhere. If it is meant to go somewhere, it isn't obvious to me... I'll attach a couple of photos. If that is not the cause of the problem, I guess I'll have to wait until I can clean the throttle body. Any thoughts or information on this pipe would be most welcome .

Cheers - John.