Hi. I'm new to the forum and would appreciate any suggestions as to how to fix a strange problem with our 97,000 mile 03 A6 Avant Sport 2.5Tdi.
If start from cold then do a short journey (say less than 5 minutes), when I come to start it again, it will not rev beyond ~1200 rpm – doesn't respond to the throttle at all. Lots of black smoke/neat diesel on the road out of the exhausts. If I leave it running it will slowly sort itself out as it gets warm. Completely reproducible.
Cold start or hot starts are absolutely fine and it runs perfectly. Problem is much reduced when the weather's hot.
This has been going on for at least a year, with the annoying workaround being to never do really short journeys,.
The local Audi indie is stumped/disinterested, having replaced the EGR to no effect.
I'd be very grateful for any ideas about what it might be.
Thanks in advance.