718 S pdk - engine stalls

[Tony_Smith]

Hi fellow Porsche fans!.
I have a strange problem with my 2017 718 S which I'm wondering if any other 718 Owners have experienced.

An irritating problem has recently developed with my engine. When i accelerate (gently!) from a junction, before the oil temp is 70C plus, the engine stutters and sometimes stalls. Immediately, I put my foot on the brake (it has the PDK box) it re-starts and i can move forward. As you can imagine this can be dangerous (and slightly embarrassing) when I'm trying to enter a junction such as a roundabout. I've tried to avoid the problem by driving in a combination of manual and drive modes in both normal and sport - but the problem still exists

When the oil temp has reached 70C plus it does not happen and I know I can confidently pull away. The car is running well with no engine management lights showing and both oil pressure and oil and coolant temp levels seem to be within normal ranges.

The car is currently with (the excellent) Nine Excellence in Crawley. They have changed the MAP Sensor but this has not rectified the fault. Looking at various 718 Forums i understand the pdk box has internal sensors which could be the problem.

Hopefully, its not a replacement pdk box required

Any help or advice would be much appreciated.

Thanks
Tony Smith

 

[Motorhead]

Hi Tony,

Very sorry to hear about your problem, especially since there’s a potential safety issue involved!

I believe that you’re in safe hands with Nine Excellence, so I assume that they’ve run their Porsche-specific diagnostics and haven’t identified any appropriate error messages which might give a clue as to the potential cause of your problem such as plugs/coil-packs?

If there’s a PDK issue I would have thought - hoped? - that a diagnostic check would have flagged-up an error. Obviously the individual engine and transmission control units talk to each other, so you’d have to wonder if the problem lies there? Unfortunately - and as no doubt you’re aware - if there’s an internal problem with the PDK transmission, officially the only course of action is to fit a replacement … at great expense!

Just as a left-field suggestion, have you tried turning off the stop-start?

Jeff

 

[malarcy]

I have heard of a similar problem but with a 981. That was crank position sensor occasionally giving erroneous readings. No fault code logged.

 

[Motorhead]

That’s a really odd one Paul, but certainly could explain the engine hiccup. The oil temperature factor is a bit odd though [not sure about the brake pedal … stop-start related?], but who knows with the interconnection of different CAN bus modules?

I wonder if a live readout on the diagnostics during a drive could throw some light on the issue?

Jeff

 

[malarcy]

That’s a good point.

Disabling stop / start would be a good idea (and the 718 has “sailing” mode - don’t know what the parameters are for that to activate.)

The diags will give information on stop start events - not sure of the details but it should tell you what the parameters were at last stop start activation (or decision not to stop start). I have only seen them in simulation, no 1st hand but imagine nine excellence would be all over that.

 

[Tony_Smith]

Hi All,
Many many thanks for your responses.
I now have the car back from 9E but they have not been able to diagnose the fault - still no error codes. They changed the MAP Sensor (someone on a 718 Forum had the same problem and a new MAP Sensor did the trick) but I still have the error. Still runs fine after oil temp is above 70C. 9E drained the gearbox oil which Adam said looked ok for its age.
Adam said he's at the stage now where all he can do is "throw parts at it the problem" - which he doesn't want to do and has suggested I take it to a Main "Stealer" to have it diagnosed as a Main Dealer will have access to the mainframe in Germany and can submit a "Technical Ticket" to find out if any other 718 S Owners have experienced this problem.
Btw - I always have to stop/start function off - interesting comment about the "sailing mode" though.
Thanks again - I'll keep you posted.
Regards
Tony Smith