Anyone got any experience of bother with the VAG 3cyl 1.4 TDI with ~75bhp?
Father has one fitted to his A2. Sometimes under load (going up a big motorway hill for instance), it appears to stop producing boost. It's quite all-or-nothing in the power delivery stakes when its working properly and its a bit worrying to drive when it's unhappy.
After stopping and starting the engine it seems to clear and could be fine for the rest of the journey. No pretty lights appear on the dash to warn of anything untoward. It doesn't produce lots of black smoke. I think, but I could be wrong that it sounds a little bit different at idle when it's not running right.
Has anyone any suggestions of where to start looking for problems?