Seat Leon Mk 1 TDI - Puff of white smoke on cold start-up

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Tue 9 Apr 2013 12:35
Seat Leon Mk 1 TDI - Puff of white smoke on cold start-up - BenG

My car is used infrequently and often sits for a week to 10 days between driving. I've noticed I often get white smoke (as far as I can tell from the driving seat) from the exhaust for a few seconds after a cold start, and the engine seems to struggle to run smoothly for a couple of seconds while smoking. Other times it starts immediately from cold without these symptoms.

The car drives normally with no loss of power or other issues and has been correctly maintained. Starting when warm there is never any smoke.

The car has the VW 1.9 TDI 150hp engine with a conservative remap to 175hp. I do not thrash it from cold or drive hard most of the time.

A friend who previously owned a VW Golf Mk4 TDI (150hp) reported the same symptoms with his car.

I did wonder if perhaps the glow plugs were suspect but the car starts pretty much immediately even at subzero temperatures. Could it be a leaking injector or another issue?

I've used BG244 fuel system cleaner and Millers Diesel Power Plus in the car previously but I guess it did nothing for the smoking issue.

Has anyone else here had experience of this issue with the VW 1.9 TDI engine?

Cheers,

Ben

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Tue 9 Apr 2013 13:28
Seat Leon Mk 1 TDI - Puff of white smoke on cold start-up - Peter.N.

Direct injection engines don't normally need glowplugs to start, unless you live in Siberia, what they do though is improve combustion when the engine is cold, so its quite possible that is the problem, or, could be there is no voltage reaching them.

Connect a meter from any glow plug to earth, when you switch to the glow plug position you should have about 10-11 volts for about 20 seconds, no volts and the relay is possiblly faulty more than 11 volts and you probably have a faulty plug/s.

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Tue 9 Apr 2013 18:00
Seat Leon Mk 1 TDI - Puff of white smoke on cold start-up - BenG

OK thanks. Will have to try each plug I guess. Not sure how to access them as they have a black rubber/plastic cap in the wiring on each plug, but I can maybe disconnect the loom.

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