D3 Intermittent Start Fault

[woodpoleman]

No not yet fixed.

Car gave up the ghost completely and was transported to local Audi. Didn't show anything on diagnostics, which was sent to Germany but still no joy. For no apparent reason car then started after a couple of weeks. Audi then cleaned earthing points and checked all fuses, relays and the starter motor.

Had the car back a couple of days when the fault reoccurred. It happened again last Friday. On both occasions it wouldn't start from a jump off a standing battery but started easily from a jump with the other vehicle engine running. Again on every occasion could hear the starter solenoid clicking but would only crank when the other vehicle engine was running. Don't know if this suggests the starter is breaking down and needs some extra oomph. Interestingly always starts from cold even this weather and starts from hot i.e. after a run stop and start again immediately but not when warm or the weather is hot.

Audi uninterested to offer any solution. Car is now with my other garage and told them if need be replace the starter motor.

Any thoughts out there will be most welcome. Can't believe this is the only A8 ever to do this!

[North2007]

An earth strap (starter) attaches to the outter side of the drivers chassis leg. It’s accessed by removing the inner guard in the wheel arch. The stud corrodes, and clamping washer needs to cleaned. I note audi say they have checked this, worth checking again.

[woodpoleman]

Thanks I've fed this to my garage hope this is the answer. Much appreciated.

[woodpoleman]

Absolutely unbelievable!!! Car is now fixed.

It has taken 3 different garages (Audi main dealer 3 visits) plus 2 auto electricians 20 months to do what 30 years ago a car mechanic would have done in 20 minutes.

It was the starter motor and instead of a lag before cranking it's now trying to throw the engine out of the car.

Except for the final breakdown visit it always started when the breakdown truck used jump leads. I carried a spare fully charged battery but it would never start from a standing battery. The eureka moment was when I twice took a jump off a running running engine suggested it needed more voltage to kick into life.

Went back to garage No 3 and told them to check the earthing strap and if OK change the starter motor. It did the trick.

[North2007]

Excellent, more helpful posts for us 8ers! Gave you back on the road.

[woodpoleman]

Thank you and everybody else who has offered suggestions and help. I hope the other guys with a similar fault get theirs fixed also.

[H-M3]

Glad to hear it’s sorted buddy! Just out of interest, did the scan not pick up the starter motor?