Hi all. I have a 2006 Q7 3.0 TDI SE, 60k miles. I had the original battery changed around 18 months ago to try and resolve slow starting (5+ seconds of cranking and eventually white smoke, both in summer and winter). This cranking caused the EPS/ ABS warnings on the dash, as the long cranking caused the battery voltage to drop. Fuel additives, injector cleaners and a new fuel filter were all done yet still the car would be slow to start on the initial start after standing for 10 hours or so, and occasionally would not even start due to the flattened battery.
On my Q7s only visit to an Audi dealer they kept the car overnight during investigations and diagnosed a weak battery, potentially caused by the short trips. Weekend trickle charging and a battery jump pack in the boot were kept for reassurance, but this was far from acceptable. I didn't believe the dealer diagnosis of needing another new battery.
Eventually I found on a forum that a Q7 in Sydney described the same symptoms as mine, and this problem was solved by replacing the starter motor. Last week I replaced the starter motor on my car and am very pleased to share that the starting is now much stronger and almost immediate, cranking with more urgency regardless of the -4 degree mornings we had recently had in the UK.
On reflection I wonder if the failing battery from 18 months ago damaged the starter motor in some way, since my starting issues coincide to around that time.
