Struggling to start when warm??

heliumwaste · 3 Mar 2025

Hi all, a couple of times now on my new-to-me 997 C2S, I've had the car struggle to start when warm. One was after about 15-20 minutes of regular driving, and one was after a spirited drive. Both times I've had the lights on at the time, which have sort of pulsed on and off as the car struggled, and rather than the engine cranking like normal, it's almost stop and start. It goes on just long enough to be unnerving!

The car had a new battery about 6 months ago and a new starter motor and Y-cable in Feb 2023.

Bigbaddog997 · 3 Mar 2025

There is a few threads on this, and indeed is a common problem.
New battery and starter motor are important causes to eliminate, my car had these without cure before my ownership.
I would probably try the bolt repair kit in the power distributor as the next step part 99761091600, aka the works most expensive bolt, as the next step.

sjgreen · 3 Mar 2025

Is it only when warm?

Could be Clutch Pedal Switch.

Gizmob73 · 3 Mar 2025

Have you had the starter cable replaced at all? If not this is a common problem with them and may well be your issue, see the link below:

https://www.pressreader.com/uk/911-porsche-world/20210701/281608128358760

Might be worth getting a proper diagnosis as it isn't a small job to do.

heliumwaste · 3 Mar 2025

Bigbaddog997 said:
There is a few threads on this, and indeed is a common problem.
New battery and starter motor are important causes to eliminate, my car had these without cure before my ownership.
I would probably try the bolt repair kit in the power distributor as the next step part 99761091600, aka the works most expensive bolt, as the next step.

Thanks for the hint

sjgreen said:
Is it only when warm?

Could be Clutch Pedal Switch.

As far as I can tell. The car cranks (I don't even know if that's the right word, so please correct me) more than my old car (2017) when cold, but I kind of expected that.

Gizmob73 said:
Have you had the starter cable replaced at all? If not this is a common problem with them and may well be your issue, see the link below:

https://www.pressreader.com/uk/911-porsche-world/20210701/281608128358760

Might be worth getting a proper diagnosis as it isn't a small job to do.

Wouldn't that be the same "Y-cable" that is quoted on the receipt as part of the "starter motor and Y-cable package" that I have from the previous seller? That was in Feb 2023, and it's barely done 2500 miles since then. That can't need doing again?!

sjgreen · 3 Mar 2025

heliumwaste said:
As far as I can tell. The car cranks (I don't even know if that's the right word, so please correct me) more than my old car (2017) when cold, but I kind of expected that.

If it cranks it won’t be the clutch switch.

heliumwaste · 3 Mar 2025

sjgreen said:
If it cranks it won’t be the clutch switch.

It would also say something along the lines of "please press clutch", wouldn't it?

Gizmob73 · 3 Mar 2025

heliumwaste said:
Wouldn't that be the same "Y-cable" that is quoted on the receipt as part of the "starter motor and Y-cable package" that I have from the previous seller? That was in Feb 2023, and it's barely done 2500 miles since then. That can't need doing again?!

Yes, sounds like you are probably safe there. If you had no record of it ever being changed then it could have been the issue but sounds unlikely now.

heliumwaste · 3 Mar 2025

I've just stumbled across this thread. My car has a Scorpion tracker fitted. Could this be related?

A

Thread '997.1 not cranking and not starting, running out of options'

23 Feb 2025

Please help if you can, I've spent many hours today trying to figure this out, reading some helpful posts here, then checking and testing, and no luck.

Porsche 997.1 2007 manual cab, with low mileage. It was working fine until the night before last. I went to start it, and it would not crank.

1. I turn on the ignition, and the dashboard lights up as expected; I turn the key further to crank, and it doesn't. The dashboard remains lit up and does not dim or change.

2. Turning the key to the crank position, the air con fan goes silent - suggesting the ignition key works.

3. releasing...

jl-c · 3 Mar 2025

He says his does not crank because the starter solenoid feed is disabled. Yours does. Sounds to me to be the dreaded bolt issue.

heliumwaste · 3 Mar 2025

jl-c said:
He says his does not crank because the starter solenoid feed is disabled. Yours does. Sounds to me to be the dreaded bolt issue.

Fair. I was wondering if the tracker could be draining the battery - but then it should have been charged while driving, shouldn't it. So probably not that. I will check the battery in case and then investigate this bolt issue.

jl-c · 3 Mar 2025

As in this possibly?

heliumwaste · 3 Mar 2025

Obviously I have no idea if this is the issue or not... but why does this lead to warm start issues, specifically? Surely if the connection is bad, it's bad all the time?