Colly

2008 Cayenne S, 70k miles, had a problem a while back where the car sometimes would not start. It would just chug once, maybe twice and stop. Usually I try again and it's fine, occasionally takes a 3rd try to start. So the garage replaced the starter motor, battery was less than a year old so I got it tested and they said it's fine.

Seems to be happening again now many months later. I notice it mostly happens when the car is warm. I come back to the car after parking and it fails to start. Rarely happens first thing in the morning.

Any ideas what this might be?

thesteve

Is it like this?
I had a similar problem. The only clue was a one-time code thrown for crank position sensor, even though the tachometer moves while trying to start.
I replaced the sensor, and quickly decided it was all a lie because the same thing happened soon thereafter once.
Strangely though, it only happened that one other time and has not returned in many months, whereas it used to be every day like clockwork, after parking for an errand and restarting when hot like you say.
My advice is buy the sensor and wave it around under the hood. Maybe hang it from the rear-view as a charm.

user 7972979723

I would say it’s likely time for a new starter..... but see you already replaced. If under your shop’s warranty, I would have them try a replacement anyhow if no charge to you.

Petza914

Sounds to me like voltage drop under the load of the starter like from a bad ground connection. I'd check the grounding points on the battery itself, where the grounds strap attached to the chassis right in front of the driver seat, and at the starter.

Could also be a weak battery or one without a high enough CCA rating.

To test the battery, with the car not running, open and close the power tailgate 3 times in a row. If the hatch stalls part of the way up on any of these attempts, the battery voltage is low from either a discharged or bad battery (weak or dead cell).