Cranking issues…

[stagmark]

I am really enjoying my 997 C4S.

I have, however, noticed that the cranking of the engine is becoming quite laboured - I was out in the car a couple of days ago, and stopped for petrol - when I went to start it after filling up, it seemed to really struggle to turn the engine over (worse than when cold - though it doesn’t feel like it turns over particularly freely then either) - though did manage it and it fired straight up.

I have noticed similar before (probably not to that extent), I have had the car on a CTEK maintainer…which it came off just as I took it out yesterday, so there shouldn’t be an issue with the battery.

Given it the cranking seems to get more laboured when hot, it seems to point to the issue associated to the starter power cable…which I came across when searching various forums.

I have found various articles / forum posts saying this is typical of this cable failing. I have also found articles explaining how to diy replace this cable - though looks quite involved (I have seen reference to 5 hours…).

I wondered if anyone has had the same issue / ways of diagnosing properly / anyone has replaced themselves, I would be very interested to hear comments and feedback.

Many thanks
Mark

 

[Robin]

Hi Mark, I had the same problem 2 years ago with starting our 1964 356C, I diagnosed the starter motor and went for a High Torque starter which worked for a while and after the manufacturer rebuilt it, it broke down again. It is now dumped in the back of my garage. I took the original Bosch starter to have it rebuilt by Guy Auto Electrics who did a great job and replaced the brushes and the solenoid contact part, (which was very burnt from the arcing) Replacing it in the car which now starts on the button. That is what you need to do dont go for after market units get your original started rebuilt. Porsche always knows whats best. see www.guyautoelectrics.co.uk. Good luck.

 

[ianthow]

I am really enjoying my 997 C4S.

I have, however, noticed that the cranking of the engine is becoming quite laboured - I was out in the car a couple of days ago, and stopped for petrol - when I went to start it after filling up, it seemed to really struggle to turn the engine over (worse than when cold - though it doesn’t feel like it turns over particularly freely then either) - though did manage it and it fired straight up.

I have noticed similar before (probably not to that extent), I have had the car on a CTEK maintainer…which it came off just as I took it out yesterday, so there shouldn’t be an issue with the battery.

Given it the cranking seems to get more laboured when hot, it seems to point to the issue associated to the starter power cable…which I came across when searching various forums.

I have found various articles / forum posts saying this is typical of this cable failing. I have also found articles explaining how to diy replace this cable - though looks quite involved (I have seen reference to 5 hours…).

I wondered if anyone has had the same issue / ways of diagnosing properly / anyone has replaced themselves, I would be very interested to hear comments and feedback.

Many thanks
Mark

Mark,

I had a similar problem, I had been on holiday for 2 weeks, car was on Ctek. On return, all green lights on the Ctek, car started OK, drove 3 miles and parked for about 5 mins. On trying to re-start, the starter engaged but would not turn the engine. Called out my friendly local garage with a battery booster, started OK. They checked the alternator was charging (14.8v I think). Took the car for a good run and all was well, but I put the car back on the Ctek and no problems the next time. What I did find was that, if the car was not used for 7 to 10 days, without the Ctek, the battery did not have enough life to start the car. I had checked for a power draw (car kept in the garage, car unlocked) but no measurable draw. Over the next couple of months, the time period before non-starting reduced to a couple of days, at which point I bought a new battery (Bosch). From the labelling, this had almost double the CCA (cold cranking amps) of the 7 year old Porsche (Moll) battery fitted (Moll 380CCA v Bosch 740 CCA). Since then (also 7 years ago!) I have had no problems and the Bosch battery is still going strong, kept alive by the same old alternator. I have only used the Ctek once in that time, when the car was SORN'd during Covid. From this I deduce that, while the Ctek may be able to detect some battery faults, it cannot determine the battery condition in terms of stored electrical capacity. It may do a good job of getting the battery up to voltage, monitoring any loss and topping this up but it cannot tell whether the battery is capable of delivering the cranking amps required for a few starts. Your battery may simply be on its way out. Check how old it is and what the warranted life was from the manufacturer, some are as much as 5 years, but many are less. If it is getting on in years, I would just replace it with one from a reputable brand (check the CCA too). If it is not too old, a competent garage or auto electrician should be able to test the battery condition, including the ability to deliver the current required by the starter.

 

[stagmark]

Thanks for the comments. I was intending to go down the road of replacing the battery anyway - though it was the fact that it became notably harder to start when it was warm / has been for a 20mile rule already…which led me to the cable worry…(which typically looks to be a right PITA to change!).
Maybe I will pull the trigger on a new battery anyway, as that is easy (and don’t believe the battery in there is that new anyway)…and fingers crossed (though not sure I feel that hopeful!)

 

[stagmark]

Bought a battery tester - all looks good with the battery in the car (came back as normal in terms of capacity/health/cranking etc… back to the drawing board!