Hi 

I have a 2007 Q7 3.0TDi

I bought the car a month ago and it runs absolutely fine once started, but here is the problem.

Starting history.
Car just cranks for 8secs ,Esp msg comes on, car fires 3sec later.  I can turn the car off, then turn on again and it starts fine. (But not all the time)

With jump start seems (impression) to fire up quickly. Car also  known to just crank for 3 seconds and just stops. Did this once after being started and left for 1hr. Tried jump start, no difference. Left for 10 mins, cranked and started. Seems like a power issue, battery, continuity of connections, starter solenoid. Occasionally seems like battery is about to die on starting, but then on retry it seems to crank fine. 

It had a Bosch S5 015 battery fitted about 16 months ago, but I can't be sure it was "coded" to the car, could this be the cause?

 

Thanks in advance

Edited June 30, 20196 yr by Scuttya1
More detail

Hello Andy, 

I think you are tending to suspect this is linked to battery/ supply problems despite the battery being relatively new. 

Bosch and the S5 ( 5 year warranty) should be a near top of the range reliable power source, so it would be understandable to assume all would be well there. Please don’t quote me, but check for yourself, but I think!  I read that there might have been a greater than average problem period with some of these - but I could be wrong. 

Type 015? Numbering might well have changed, but I thought 015 was a near match for the old 038 which was a small output battery, and would be totally inadequate for your car. Have you double checked what the correct battery should be for your car, and confirmed the one currently fitted is indeed correct? Let’s assume it is.....

If so, if this were mine, I would be starting by getting the battery efficiency checked. Make sure it’s fully charged before having it tested. Halfords test these. Whether you buy from them if a new one is needed is a personal choice. 

It would also be well worth checking all associated main earth connections, but I would go at this one step at a time - first step would be to eliminate - or otherwise - the battery being at fault.

Perhaps you could let us know how you get on. 

Kind regards, 

Gareth. 

 

Many thanks for the response.

I have double checked the battery which is currently fitted

S5 015 Bosch Car Battery 12V 920A/110Ah 

Type 020 S5015.

This is the correct battery for the vehicle. I will need to get a charger for this battery to ensure it has been fully charged prior to a garage checking. Can you advise of a suitable charger (output etc). I guess I can charge to the under bonnet connectors?

 

Kind regards

Resolved.

Battery was fine, just needed longer runs to charge. Starting issue was resolved with a change of crankshaft sensor.

 

Andy