Hi on cold start up I have noticed quite a fog of blue gray smoke from my exhaust.

Could this be unburned diesel etc or further problems.

Hopefull its just me being paranoid.

Thanks

Hi on cold start up I have noticed quite a fog of blue gray smoke from my exhaust.

Could this be unburned diesel etc or further problems.

Hopefull its just me being paranoid.

Thanks

Mine occasionally kicks out a bit on very cold mornings as well ...probably just incomplete combustion in the very cold cylinder heads. Soon clears and no oil usage, so I figure it's just one of those things.

Does the engine hesitate occassionally with starting? Do you need to crank it for more than 1s-2s before it starts? If yes, continue

Since it is V6 TDI, and engine I know rather intimately , you probably need to do a couple of things:

1. check glow plugs with resistance meter (ohm meter) if any are blown, should be well under 2 ohm. Replace any blown / high resistance glow plugs before anything else.

2. check basic injection timing and adjust it so it is at the advanced end of tolerance range. I set mine to 0.6deg - 1.0deg ATDC. You need a VCDS cable, or a mechanic/stealer with VAG code reader to do this. Adjustment is 3 screws under the timing belt cover, and is very sensitive, it is probably about 1/5th of 1 tooth size on the belt between flawless starts and occassional clouds of fuel vapour we are talking here.

There was a bulletin a good while ago on fixing cold start problem, and it described setting the basic injection timing quite well. From my experience, this was well worth doing as factory injection timing was set to over 2deg ATDC and every 3rd start I'd get a cloud of fuel vapour as you described.

Edited 13 December, 201114 yr by dieselV6

Does the engine hesitate occassionally with starting? Do you need to crank it for more than 1s-2s before it starts? If yes, continue

Since it is V6 TDI, and engine I know rather intimately , you probably need to do a couple of things:

1. check glow plugs with resistance meter (ohm meter) if any are blown, should be well under 2 ohm. Replace any blown / high resistance glow plugs before anything else.

2. check basic injection timing and adjust it so it is at the advanced end of tolerance range. I set mine to 0.6deg - 1.0deg ATDC. You need a VCDS cable, or a mechanic/stealer with VAG code reader to do this. Adjustment is 3 screws under the timing belt cover, and is very sensitive, it is probably about 1/5th of 1 tooth size on the belt between flawless starts and occassional clouds of fuel vapour we are talking here.

There was a bulletin a good while ago on fixing cold start problem, and it described setting the basic injection timing quite well. From my experience, this was well worth doing as factory injection timing was set to over 2deg ATDC and every 3rd start I'd get a cloud of fuel vapour as you described.

Thanks for the reply this is exactly what is wrong with my car I will try all of the above and hope this help.

Thanks again

Make sure basic injection timing is set on a fully warmed up engine, as it tends to walk ~0.5deg even from half-warmed to fully warmed engine. I got mine perfect on 3rd or 4th attempt, we are talking 1mm-2mm shift of the injection pump belt here.

I had the same problem. Turned out 5 out of 6 glow plugs were kaputt!

3 broke off in the RH cylinder head (Bosch mechanic - but I don't think it was really their fault - they have come across this before on the same engine type), so needed a new cylinder head. Expensive job, not so much for the head (£600) but all the rest, cam belt kit £180, water pump £50, glow plugs (Skoda genuine Beru made in Germany) £120, and around £800 in labour!

If you do decide to change the plugs, make sure that there is several days' worth of anti-seize compound soaking before reaching for the tool box. And I mean use stuff stronger than WD40, in ample quantities, and let us know how you get on!

On these engines the glow plugs are thin, fine threaded, and exposed to road salt, grit, and corrosion prone. The thread engagement is also quite short, so in short the risk of stripping a thread or brewing one is quite high! Just google it, lots of Audi forums document this.

Edited 30 December, 201114 yr by oh_superb

glow plugs (Skoda genuine Beru made in Germany)

We may be suffering an EU/IMF bailout but one of the BERU heater plug plants is still in Ireland (at least it was when I passed it yesterday) and I dont think we are part of Germany ......yet.... :)http://www.beru.com/production-in-ireland

BTW some of the locals may be to blame for some of the wiring faults too http://www.kostal.com/english/thecompany/subsidiaries/ireland.html There are some differences in the spec they sent to Skoda compared to VW. Better sealing of Skoda window motors being one.

Edited 31 December, 201114 yr by Hoverurb