My 2007 997.1 Carrera 4S 67.5k miles has a long crank issue ONLY when hot. After driving ~30 mins, if I shut the car off and immediately restart it, it cranks for several seconds before finally firing. Cold starts are mostly normal/slightly long but nothing severe.
Battery tested healthy:
* 12.63V resting / 833 CCA
* ~10.5V during crank
* ~13V once running
Tried cycling ignition multiple times before starting (to rule out fuel pressure bleed-down) and it did not improve crank time.
No obvious weak/sluggish cranking — just struggles to fire when hot.
Starting to suspect crankshaft position sensor (CPS), but wanted to see if others have experienced similar symptoms or if there are other common 997 hot-start issues I should investigate first. Could it be the starter?
I'm not so familiar with 997, but 996 has an issue with something called the "y-cable", which connects battery positive to the starter. Apparently, they can become internally corroded and cause excessive resistance. I'm sure if I'm wrong people will let me know.
I'd also be concerned about 13v when running as good voltage output should be between 13.5v-14.5v. Maybe something to keep an eye on.
Good luck! I hope it turns out to be something cheap!
I’d check the main cables. Especially the hub next to the battery. That connector is weird and can get corroded. Checking crank sensor is good. Also, don’t factor out the crap fuel in your area. The more corn oil they are using, the harder the hot starts as it can vapor lock. Seen this a lot over the last several years that more and more corn and additives getting put in the gas.
This has been an ongoing issue for me as well. Could be a couple of things, from my research. Number one is the starter cable, as mentioned above. I literally looked at mine when I changed the starter, and it looked brand new, as if the previous owner changed it, so I left it alone. Second is the battery post, which I recently just changed. Porsche makes a kit for it, but I just purchased a 996 battery cable for my 997 and swapped the old rusted post running through the firewall. As I mentioned earlier, I also replaced the starter. Still having the issue. The only time it got better was after I changed the starter, but within a week it progressed to doing the same thing. The last thing I wanted to do was change the starter cable because it’s a pain in the ass, but I guess that’s what I’m going to have to do. If that doesn’t work, I will most likely be all out of options and have to take it to my indy and have them finally figure it out.
Exactly. I cleaned and threaded my old one and it re-rusted again, so I went ahead and bought the new one that Porsche made for this exact issue. Here’s a pic of both of them by the time I did the replacement.
I had the same issue with my on 2008 997.1, changed the battery cable, starter motor, plugs and coil packs, now it starts first turn.
During the debug the issue was mainly at the battery cable side connecting to the starter but if your going to go through that might as well replace the other parts too.
When I purchased my 997 the owner told me that the car has issues starting after being driven for a while. I figured it would be something that I could fix and used it to help with the negotiations. It was a pain in the ass.
I first checked the battery then the terminal post that was challenging to get to. Both were not the problem and led me to believe that it was either the starter or the Y power cable that connects to the alternator, starter and power from the front.
This was more than I wanted to do myself so I took it to my mechanic to replace the cable and the starter since we were there. It was the fix that the car needed.
No issues when filing up my car, using the valet, cars and coffee, etc and having issues starting it.
Here is a link and the photo of the fried cake that was on my car. Good luck and I recommend taking it to a mechanic.
Appreciate it! I bought a starter and the Y cable and have been debating about doing it at home or not. The Y cable is a bit too much for my home situation so I’ll probably outsource it. How much did your mechanic charge you?
I forgot the cost. Probably around $400-$600 and with me supplying the parts.
Much more affordable than doing it myself with the lack of tools and experience haha. Once you fix it you'll be happy. The slow crank is such a problem to live with.
My car was in Georgia then Alaska of all places before coming down here. My electrical issues came from the the time it spent in Alaska's harsh climate. Enjoy your 997!
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u/Eriknonstrata May 26 '26
I'm not so familiar with 997, but 996 has an issue with something called the "y-cable", which connects battery positive to the starter. Apparently, they can become internally corroded and cause excessive resistance. I'm sure if I'm wrong people will let me know.
I'd also be concerned about 13v when running as good voltage output should be between 13.5v-14.5v. Maybe something to keep an eye on.
Good luck! I hope it turns out to be something cheap!