Recently i've been getting a clicking noise from the engine when the engine is cold and at idle, the noise completely goes when warmed up. The car runs well, returns good MPG (for a quattro) which has improved with a recent turbo change. On start from cold the engine gives a puff of blue smoke that smells like unburnt deisel, doesn't require excessive cranking to start though, I scanned with VCDS a few months back and it flagged glowplug errors which I guess might account for some of the blue smoke. I ignored them at the time as it was summer and they don't really do a great deal unless it's really cold. I'm going to have to have a look at the values of the injectors in VCDS to see whats going on but is it plausable that there is an injector fault when cold that corrects itself as the car gets up to temperature? Any ideas on what an Injector costs, fitting should be fairly straightforward looking at the diagrams.