2006 q7 3.0tdi starting problem cold or hot

[Siheaney]

Hi all,

I own a 2006 q7 3.0tdi. I have been having starting problems, it cranks over fine but can take up to 10seconds then starts and there is white smoke. I have read on a few forums people with this problem but none have posted whether they found the solution. I have had battery issues in the past but car has a new battery, been fully charged by a garage and still seems to do it so do not think it is a battery issue. If anyone has had this issue and resolved it help would be very much appreciated! Thanks

[Trevor]

Hi Simon,

Is the starting fault when the engine is hot or cold?

If only when cold, I would suggest the glow plugs may be faulty.

The white smoke suggest unburnt or partially burnt fuel so either glow plugs or compression could cause this....is the engine oil due for replacement?

[Siheaney]

Thanks for responding, it can happen either hot or cold it's very random. It has just had a service so yes has new oil. What do you mean by compression? Engine compression? I have very limited knowledge about cars so have to bare with me, just spent £900 on it on other faults so hoping to avoid another massive bill! 

[Trevor]

sorry, by compression I meant engine compression which can be affected by engine oil quality.

Other possible faults could be fuel pressure dropping slightly, probably best to run a scan on the engine to determine pressures, voltages, etc.

For the cost of a scan by a reputable garage/specialist it would eliminate any guesswork and money ill spent.

Good luck and let us know how you get on with it.

[singh4406]

hey guys im also having the same problem its the TDI engine  2007 model , had battery replace and glow plugs my oil is good , any other options