rutthenut

Hi there,

I've read a lot of threads and useful info about starter problems on the Cayenne V8, but not quite found what I would like to know from those.

I've got a 2013 GTS with the 4.8 V8, which won't start. Actually, it won't crank at all.

When opening door and putting in the key, all the usual clicks and whirs as pumps start up, etc.
Turning the key, nothing. Do not hear the starter solenoid click at all, so not a slow/weak start problem.
Using a jump pack on the posts makes no difference at all.

Battery was around 12.2v which is a bit lower than desired. The car often gets started and used for very short journeys, so that would contribute to that as it doesn't run long enough to fully charge it each time. However, enough medium/longer runs do top it up, enough for stop/start to kick in. In the winter, we did find that voltage would drop lower as more power needed to start and lights/heaters get used then.

The no-start problem did occur for the first time a couple of months ago - explanation below - but then seemed 100% fine so thinking (hoping) it was then resolved.

As the fault has now reocurred, and fault-finding showed me nothing new, I put in a new battery. The old one was the original, so had never been changed. Much as expected, that made zero difference. All ancillaries work fine but turning key does not turn the engine.


To go back to first instance of the problem, around Easter time, car had started, been driven a mile up the road to take dog for a walk, then parked. On return to the car, it would not crank and hence not start.
At that time, I tried a couple of different jump packs, checked the relevant fuses in both sides of the dash, found nothing wrong in there.
Trying to start without foot on brake put up warning, so believe that sensor is working ok. Also, trying to start in Neutral put up a warning too, so looks like both of those safety checks are operating as they should.

Called out RAC recovery to investigate. When engineer arrived, went through the same initial checks, tried to jump it, checked fuses, used code reader and found nothing reported (though not convinced his kit could talk to all the Porker systems). Next up was to disconnect the battery for five minutes to see if a reset cleared any issues. Still no joy. He then called back to base for help on tracing the wiring, finding the starter relay and fuses that live under the bonnet. The 40 Amp fuse was ok, not blown. Could tell that relay clicked when trying to start, which should also rule out safety checks preventing start. Then worked through with test leads to check power continuity, whilst turning the key. When leads were put across the fuse contacts, with fuse out, I then heard the starter solenoid click. Seems that pointed to the problem. Put in a replacement 40 Amp fuse and car then started just fine. Didn't turn over slowly at all. Worked repeatedly if switching off, removing key, then starting it again.

Looked like the fuse had gone duff, though resistance looked fine and it was definitely not an open circuit.

Since then, the car had been starting normally, voltage fine and stop/start turning engine off in traffic and at junctions, so seemed it was just the dodgy fuse. Did seem a lot to hope for, but no other problems apparent once that had been replaced.


Until I needed to move the car out at half six last Sunday morning to get another car out from the garage. Started Porker, parked it outside house, got other car out, parked that out the way, went to Porker and lo and behold, no response to the key. Did the same checks on voltage, tried another fuse, relay clicking ok but solenoid not responding. Tried jump pack again, just in case. Silence. Had to push the Pig back onto the drive - yeah, like that is fun at seven in the morning with no power steering, a gravel drive, and already meant to be on the road to somewhere else.

Back to where I am now.
Car is on the drive, has a new battery, still does not make the solenoid do anything.

My assumption is that the starter/solenoid has failed and this time will not recover whilst faffing with fuses and wiring.

However, as it's a fair bit of work (quoted at 5 hours or so) to change the starter, I would like to know if there is anything further I can check before committing to get that done. Local specialists are all booked up for weeks, so can't get them to verify anything (or change the starter) any time soon.


If I use a test lead to connect from the 40 amp fuse to the 'out' pin of where the relay sits in the under-dash fuse box, should that cause the starter relay to click into operation? Or is there some other section of wiring I can get to between relay and solenoid?

Any recommendations on what else I could check, with basic digital voltmeter, to further analyse the problem?

My hesitance to directly blame the starter motor is because of how it started working again after recovery engineer was testing connections in the relay/fuse box area. If it is something else up there, I'm gonna be pretty miffed to pay to have the starter changed if that is not the problem.

I know older cars had problems with coolant pipes leaking, that cause the starter to die. Not had any coolant issues and I believe the pipes should be the later ones on this car already, so don't feel that is likely to be the cause in this case.

Could well be that the starter/solenoid has just now had enough and wants replacing.
Thought that of the battery too, of course, but that was a couple of hundred quid and a little bit of my time so worth trying first.

Any thoughts from the clever bods on here?