When I was changing the brakes on the Fab last weekend I took the intercooler pipework elbow off that sits over the brake fluid reservoir to allow for easier access and happened to look into the throttle body (or whatever it is, it had what looked like a throttle butterfly in it) only to discover that the butterfly was covered in what looked like grit. Is this normal? I cleaned as much off it as possible and the car seems to be running fine but it's concerned me a bit! Is this caused by exhaust gas recirculating and it's just a build up of soot and oil deposits or something more serious?

Edited 1 April, 200917 yr by Schern

That's the EGR assembly, it does get a lot of cr*p in it, and yeah, unfortunately what you're describing is pretty normal.

You can turn down EGR in VAGCOM (VCDS) which will help a little

That's a relief! I thought that I'd got a hole in some of the inlet pipework and it had been sucking in dirt and road salt and all sorts! I wondered if it was the EGR but I changed the gasket to eliminate the stutter and it wasn't really anywhere near that bit! Thanks for putting my mind at rest

The amount of crud that collects in the EGR is quite amazing. Hopefully someone more knowledgeable will be able to explain it better, but my basic understanding is that the crank case vented gasses and some oil and so forth mix to form that sticky crud.

EGR in itself is used under light load to try to minimize NOx emissions from what I recall.

The amount of crud that collects in the EGR is quite amazing. Hopefully someone more knowledgeable will be able to explain it better, but my basic understanding is that the crank case vented gasses and some oil and so forth mix to form that sticky crud.

EGR in itself is used under light load to try to minimize NOx emissions from what I recall.

Spot on. Can be reduced by fitting elephant hose mod to vent PCV to a catch can, or atmosphere.