2014 Boxster S Misfiring
01-16-2022, 02:33 PM
#1
2014 Boxster S Misfiring
Hi!
I have a 2014 Boxster S (UK spec, manual, PASM/PSE/Sport Chrono/PTV) 34k miles which has started experiencing misfiring. I've owned the car since April 2018 and until now it's been faultless.
The first sign of trouble occurred when I was accelerating up to 70mph to join a motorway on the 19th December, when the car suddenly lost power and started running very roughly, and I got some messages logged on the information display: "Fault - engine control - possible to drive on", "PSM loss - possible to drive on carefully" and "Start/stop operation deactivated". I stopped the engine while the car was rolling and restarted, and everything came back properly and the engine ran normally. And then the issue happened again some seconds later. I repeated the restart procedure, and the fault messages cleared and the problem was gone. I continued my journey, and the problem didn't occur again. Because of Christmas/New Year stuff going on, I didn't have the opportunity to drive the car, instead using my daily which is a 1992 BMW 730i.
My next opportunity to drive the car was in the new year, and the problem occurred again within seconds of starting the engine. This time, the check engine (MIL) light came on, so I decided to dig out my generic Bluetooth code reader which I've had for at least 10 years. Using the Android OBD Fusion app, I saw that there were misfires recorded on several cylinders, but with most of them on cylinder 4:
As the car warmed up, the problem disappeared, but a day or two later, there were more codes and this time the problem seems to be cylinder 5!
Now it seems that there are a few misfires on all of the cylinders, but the vast majority are on cylinder 5. And the problems disappear once the car warms up to somewhere near normal operating temperature.
I was considering swapping the coil packs on cylinders 5 and 6 (I think those are the rearmost on the passenger (left hand) side of the (RHD) car and seeing if the problem moves. The final stage for the blower on my old BMW has failed, and so I've been using the Porsche more, avoiding engine loads when it does misfire. But the more I use the Porsche, the less the problem happens. In fact the last time I took the car out, the fault didn't occur at all. I'm tempted to clear the codes now and see what happens.
The car was last serviced in Summer 2021 by Brooklands Service Centre where the accessory belt was replaced and it's only ever been touched for service work by OPCs. I can't remember if they changed the spark plugs too but I have a feeling they might have. But two things have happened since then. I stopped driving the Boxster Daily and used it only when I had the prospect of an interesting non-motorway drive (i.e. no supermarket shopping trips or general errands) and E10 fuel was introduced in the UK. But parts obviously do fail, and from watching Rainman Ray's excellent YouTube channel, I see that misfires are nearly always caused by faulty coil packs. I don't use super unleaded (97/98 RON and 0-5% ethanol in the UK generally) as until now I've seen no reason to.
My level of mechanical competence is that I am happy to change my own brake pads and rotors. On my BMWs I am happy to replace engine ancillaries (I've done my thermostat, power steering pump, alternator, fuel pump and I'm about to replace my dampers on my 730i as it appears to have no damping whatsoever. Also my 210k mile 2001 330Ci which I've owned from new has a failed head gasket and possibly more damage due to a cracked expansion tank, and I'm gathering tools and knowledge to attempt an engine rebuild. Never done any work on my Porsches, of which this Boxster S is my second.
Some hopefully pertinent questions then:
1. Are these cars particularly sensitive to either octane or ethanol when it comes to fuel?
2. Are premature coil pack failures common?
3. Would you do what I have planned to do, which is swap coil packs between two cylinders and see if things change?
4. Or since the problem has more or less disappeared by itself since I am using the car more often, clear the codes and either drive the car more in the winter, or only drive it in summer?
5. Have I missed anything? I don't have a Porsche specific scanner. One might be a good investment, but since I have several cars, I'd prefer one that's not Porsche specific.
Apologies for the huge screenshots. I can't find a way to shrink them on the site easily. I'm attaching two html reports from OBD Fusion which provide far more detail including freeze frame data.
Many thanks for any insight!
Alex
I have a 2014 Boxster S (UK spec, manual, PASM/PSE/Sport Chrono/PTV) 34k miles which has started experiencing misfiring. I've owned the car since April 2018 and until now it's been faultless.
The first sign of trouble occurred when I was accelerating up to 70mph to join a motorway on the 19th December, when the car suddenly lost power and started running very roughly, and I got some messages logged on the information display: "Fault - engine control - possible to drive on", "PSM loss - possible to drive on carefully" and "Start/stop operation deactivated". I stopped the engine while the car was rolling and restarted, and everything came back properly and the engine ran normally. And then the issue happened again some seconds later. I repeated the restart procedure, and the fault messages cleared and the problem was gone. I continued my journey, and the problem didn't occur again. Because of Christmas/New Year stuff going on, I didn't have the opportunity to drive the car, instead using my daily which is a 1992 BMW 730i.
My next opportunity to drive the car was in the new year, and the problem occurred again within seconds of starting the engine. This time, the check engine (MIL) light came on, so I decided to dig out my generic Bluetooth code reader which I've had for at least 10 years. Using the Android OBD Fusion app, I saw that there were misfires recorded on several cylinders, but with most of them on cylinder 4:
As the car warmed up, the problem disappeared, but a day or two later, there were more codes and this time the problem seems to be cylinder 5!
Now it seems that there are a few misfires on all of the cylinders, but the vast majority are on cylinder 5. And the problems disappear once the car warms up to somewhere near normal operating temperature.
I was considering swapping the coil packs on cylinders 5 and 6 (I think those are the rearmost on the passenger (left hand) side of the (RHD) car and seeing if the problem moves. The final stage for the blower on my old BMW has failed, and so I've been using the Porsche more, avoiding engine loads when it does misfire. But the more I use the Porsche, the less the problem happens. In fact the last time I took the car out, the fault didn't occur at all. I'm tempted to clear the codes now and see what happens.
The car was last serviced in Summer 2021 by Brooklands Service Centre where the accessory belt was replaced and it's only ever been touched for service work by OPCs. I can't remember if they changed the spark plugs too but I have a feeling they might have. But two things have happened since then. I stopped driving the Boxster Daily and used it only when I had the prospect of an interesting non-motorway drive (i.e. no supermarket shopping trips or general errands) and E10 fuel was introduced in the UK. But parts obviously do fail, and from watching Rainman Ray's excellent YouTube channel, I see that misfires are nearly always caused by faulty coil packs. I don't use super unleaded (97/98 RON and 0-5% ethanol in the UK generally) as until now I've seen no reason to.
My level of mechanical competence is that I am happy to change my own brake pads and rotors. On my BMWs I am happy to replace engine ancillaries (I've done my thermostat, power steering pump, alternator, fuel pump and I'm about to replace my dampers on my 730i as it appears to have no damping whatsoever. Also my 210k mile 2001 330Ci which I've owned from new has a failed head gasket and possibly more damage due to a cracked expansion tank, and I'm gathering tools and knowledge to attempt an engine rebuild. Never done any work on my Porsches, of which this Boxster S is my second.
Some hopefully pertinent questions then:
1. Are these cars particularly sensitive to either octane or ethanol when it comes to fuel?
2. Are premature coil pack failures common?
3. Would you do what I have planned to do, which is swap coil packs between two cylinders and see if things change?
4. Or since the problem has more or less disappeared by itself since I am using the car more often, clear the codes and either drive the car more in the winter, or only drive it in summer?
5. Have I missed anything? I don't have a Porsche specific scanner. One might be a good investment, but since I have several cars, I'd prefer one that's not Porsche specific.
Apologies for the huge screenshots. I can't find a way to shrink them on the site easily. I'm attaching two html reports from OBD Fusion which provide far more detail including freeze frame data.
Many thanks for any insight!
Alex
