Starting problem - FIXED

[Bigdave1230]

Had a fault on my 2008 Q7 where the car cranks over for 2-3 seconds then stops cranking. Starter turns over fast when it does crank. Leave the car for 20 mins and it will crank and fire up no problem. Seems to happen when the car was warm but I can’t say it never did it when cold as I can’t remember if it did. Vcds shows no fault and when it’s running it doesn’t miss a beat. Very intermittent and very very very 🤬ing annoying............................... Replacing the crank shaft sensor seems to have cured it. Hope this helps anybody with a similar problem. 👍🏻

[Trevor]

Thanks for the update information Dave....I have altered the topic title to show the issue has been resolved

[AndrewC91]

Exact same happening mine, its 2008 aswell and seems to be when warm and when you leave it for 15-20minutes it fires up, was the camshaft sensor a big job to change? Only started happening the last 2 weeks and has happened 3 times in that space.

[Bigdave1230]

It’s not a hard job but it is fiddly. I’d recommend doing it on a ramp as you need to take the wheel off and the engine under tray to get access. It’s only held in with one allen key bolt. The sensor was about £60 I think. Mines a 3.0 v6 but I think the 4.2 v8 has 2 and might be in a different place so would be worth checking beforehand  if yours is a V8.

[Bigdave1230]

Sorry just seen your wording! I changed the crankshaft sensor not the camshaft sensor