Audi A6 2.0 TDi starting problems

[blueskies1974]

Hi there. May I ask if anybody has an opinion on what may be wrong with my car? It is a 2012 A6 2.0 TDi. It's had this intermittent starting problem for a while, but it has become worse. Sometimes when i push the start button, the engine turns over for a fraction of a second, stops and then the glow plug light flashes. This also happens when the stop / start function switched the engine off at a red traffic light. Pushing the button to switch the ignition off and then on again used to work fine, but lately all that works is holding the button in. The engine then turns for several seconds before it starts. This doesn't happen when the engine is cold, but only at normal temperature. It also sometimes give me a message that the stop / start function is malfunctioning. Any ideas on what the problem might be? I had a diagnostic done on it, but no fault codes were stored. Many thanks in advance!

Peet

[panic-mechanic]

Stop / start systems is a great way to go through starters and batteries. Disable the damn thing everytime you get in the car and half your problems will diappear.
These are one of those that you will actively hunt down by driving with vagcom plugged in and open so you can see what cycle the start is interrupted at.

[blueskies1974]

Hi many thanks for the reply. Someone suggested that it might be the crank sensor?

[panic-mechanic]

If it is it will be easy to see that in vcds. Display rpm and if there is 0 while the engine is turning over you have found the problem. But it 'could' be a boatload of things and without actually trying to do diagnosis it is simply a guess. And you can play the guessing game a long time when younstart guessing on stuff like that.