Engine misfire

[johnheadland]

Hi
had the dreaded engine light come on yesterday. 2015 981 Boxster.
Plugged it into my Durametric and got 5 dtc’s come up on engine module.

P0100 - Maf Sensor
P0200 - Fuel Injector
P0300 - Multiple cylinder missfire
P0000 - No Dtc’s detected ?
The engine misfires at very low revs only, such as pulling off forward or reversing.
I performed an actual engine module test and observed the values for each cylinder. Cylinder 1 values were different to 5-6 which were all the same.
My thought was possible coil pack playing up but does anyone else have any ideas please?
Many thanks.

 

[elstonc]

You obviously know more than me, John, but I had a similar fault a couple of times on my 2013 918. The warning message is that the stability control has been turned off and to proceed with caution. The cause was a misfire, sometimes too brief to notice. In each case it needed a new coil pack for the offending cylinder.

Best,

Chris

 

[Motorhead]

For a single cylinder misfire I would have thought that a spark plug/coil pack fault should be your first port of call John. For multiple cylinder misfires you may want to consider replacing the VarioCam solenoid if you can identify the offending bank.

Jeff

 

[johnheadland]

Thanks Chris,

I suspect it’s a similar problem to yours was. Just wish the Durametric results were more specific.

Regards John

 

[Motorhead]

Clearly Durametric has its limitations John, as you would expect from a basic diagnostic tool. Unfortunately you’re going to need PIWIS or its equivalent to gain more detailed information.

Jeff

 

[CLIFFWILKINS]

As been said already I would check coil pack or plug first.

Hope you get it sorted.

 

[malarcy]

did those codes all come back after you cleared them ? You could be looking at historic codes.

if you have a difference between cyl 1 and the others that is reproducible then suggest swapping Coil packs betweeb 1 and another cylinder. if the fault moves it’s coilpack.

also

a failing coil pack may not throw a code - the car knows it told the coil pack to spark and it knows if it was successful but it doesn’t know if that spark went through the plug or out the side to the head - if it does it a lot then perhaps the car works out something isn’t quite right but i have similar on other (non Porsche) cars.

 

[Ryan9729]

Inspecting the actual spark plug will tell you all you need to know. If it's not a nice tan brown colour then you'll need to work back from there. A coil pack is a service item (they have a finite life), but it's not always the issue for misfiring.

 

[johnheadland]

Thanks everyone for your assistance.

I succumbed to taking the car to the garage for a proper diagnosis.

The misfire appears to be on cylinders 1 2 and 3 which apparently points to a vario cam solenoid stuck open causing misfire at low speed. If was stuck closed the misfire would be at high speed. So the drive home was very exhilarating !!!