tag1_uk

Hi all,

After having spent a small fortune on some repairs at the main dealer on my new 2nd hand Furby, I'm still not quite satisfied that it is running correctly. I've just had the equivalent of the full 40,000 mile service and a new cambelt/auxilary belt (the car is only at 33,000 miles but it is nearly 6 years old so I got the cambelt done to be prudent). Anyway, I'm still not satisfied with the tickover - it often struggles to maintain an even idle speed, seemingly hunting around +/- several 100 rpm. This is made worse when you switch things on and off in the electrical circuit e.g. power steering, aircon, heated rear window. The ECU naturally increases the idle speed to account for the increased current draw, but the idle speed doesn't seem very able to settle down - the same thing happens when you turn something off - the idle dips a little but doesn't necessarily settle down. It doesn't do this all the time, but enough to be worrying. Even if you dab the accelerator when it is doing this behaviour, it still doesn't idle smoothly when the revs return back to idle speed. These symptoms seem to be worse since the service although the engine is otherwise running better (more power (although none below 2000 rpm), quieter etc.).

Am I right in thinking that it is likely to be just a throttle body clean and alignment check? Could the EGR/lambda sensor be at fault? (I did report this to the main dealer but since there was no problems reported on the computer they weren't too inclined to do anything). As long as they've got a vagcom system, should I have any reservations about getting this kind of thing checked out at a non VAG garage?

Cheers in advance.

ExAudiSi

Could be a faulty temperature sender. Another of the VAG common failures unfortunately.
I believe that this can cause the idle speed to wander up and down and may also cause issues with starting, particularly when the car is warm.
I don't think that the temperature send shows up as a fault unless anyone actually looks at the values that it is giving using vagcom or diagnostic computer.

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My other car is a Porsche....

fordfan

A throttle body clean (with it removed) and at the same time a clean out of the EGR system is usually beneficial to the running of the engine. These items are not part of a service schedule and shouldn't take no longer than an hour to do.

Take it to a garage that has VW knowledge as it sounds as though the dealer isn't too interested in trying to find a cause if the computer says that everything is OK.