I've not tried this yet, but can Tdi's be bump-started? I have found it an invaluable method of starting a car if the battery is flat (especially if the interior light was left on at a mountain pass and I went walking all day . . . ) with my previous cars, which were all petrols.

I suspect there may be issues if the cylinders aren't warm enough to combust the diesel, but that aside from that, are there any other issues?

Just wondering . . .

Unlike a petrol engine it is very hard to bump start a diesel.

The high compression makes turning the engine over very difficult/impossible without a tow from another vehicle. If you are pushing it, dropping thre clutch usually causes an abrupt stop. Plus the tow needs to be long enough to allow the cylinders to heat up before ignition occurs. Also if the battery is completely flat there may not be enough voltage to run the electronics that controls these modern engines (not a problem on old totally mechnical diesels). What does your manual say?

Forget it. No hope although modern diesels are damned reliable (touchwood) so shouldn't get to that stage hopefully. i see the problem being getting a sufficient pre-heat in the cylinders as already stated.

I did have a flat battery once on my 1.9 sdi and was able to bump start it, but it was no easy feat. Three guys pushing pretty hard to get as much speed as possible so that you stand a chance of getting the engine turning over to fire before the high compression brings you to a rapid stop.

I guess it's the same for TDIs. Brute force and ignorance I say

I have bumped started my pd100 with out any difficulty, it was parked on a slope aprrox 1:10, rolled it about 3 metres and used 3rd gear. Just drop the clutch back down as soon as it fires.

Don't know what damage it might do though.

No problem. I stalled mine in traffic the other day. I dipped the clutch let it roll , let the clutch out and it started no problem. Dont do it too often !!

In the winter from stone cold with no battery voltage, no chance IMO.

You at least need enough voltage to heat the glow plugs and run the car's electrics.

J.