Diagnosis help

[Babw]

Picked up my roadster after 4 months of sitting at a Porsche dealership and all is not well.

Car seems to pull hard, no knocking or any funny noises however when hot and driving for over 15 miles the ECU seems to be pulling power.

No problems at all starting from cold but hot starting is a no go. It's only thrown a code once, P130A and P0A00 which is a common misfire code and coolant temperature sensor.

Battery is fully charged (the lack of cold start issue makes me think it's not a dying battery or alternator.)

I'm thinking cam position sensor and/or the engine coolant temperature sensor. Car is on 45000 miles and plugs replaced within the past 5k miles, I've checked all the coils and they seem to be ok.

Help appreciated

 

[clarker63]

Picked up my roadster after 4 months of sitting at a Porsche dealership and all is not well.

Car seems to pull hard, no knocking or any funny noises however when hot and driving for over 15 miles the ECU seems to be pulling power.

No problems at all starting from cold but hot starting is a no go. It's only thrown a code once, P130A and P0A00 which is a common misfire code and coolant temperature sensor.

Battery is fully charged (the lack of cold start issue makes me think it's not a dying battery or alternator.)

I'm thinking cam position sensor and/or the engine coolant temperature sensor. Car is on 45000 miles and plugs replaced within the past 5k miles, I've checked all the coils and they seem to be ok.

Help appreciated

someone will have more insight on this, but surely you can go back if you have just bought it and there are problems... especially from a premium dealer?

 

[RedUn]

Obvious question but is the fuel in it new? If its 4 months old it'll be pulling timing.

 

[Babw]

Clarke63 - I've owned the car for a number of years, it was just at the dealership as I had to travel to pick up my Cayman after service then lockdown hit.

New Vpower as soon as I picked it up and good idling when cold, engine sounds perfectly normal. Cold start is after a couple of cranks, no smoke or spluttering.

When hot the engine cranks and it wants to go but ECU not providing spark as the engine wont fire into life. Very strange.

 

[Rockhopper]

This would be a typical crank shaft position sensor fault on most cars but it should throw up a code. Cam shaft position sensor errors don't usually prevent it starting.

 

[Babw]

Would you not think it’s a engine temperature/coolant temperature fault?

As if the sensor is faulty and the car thinks it’s much hotter than it actually is then it’s preventing a start. That’s my theory anyway.

 

[Rockhopper]

Sorry I assumed by your post saying its a common error that you'd eliminated it?

 

[ph001]

When you try to start it hot, do all the normal lights come on the dash when ignition is at position 2? There is a well documented problem with ignition switch that does just as you describe... the tell tale sign is that the normal lights don't come on at pos 2, so you are essentially trying to start the car from the ACC position. It will crank but not fire.

 

[Babw]

Sorry I assumed by your post saying its a common error that you'd eliminated it?

I’m not sure I know what you mean but I cleared the misfire code and it hasn’t returned.

What I mean about the ECT is that if it’s faulty then at higher temps it’s throwing the fault causing the car to misbehave.

I’ll check the ignition switch and light sequence tonight. Only now I realise these cars are getting Jon a bit as in the past few months I’ve replaced all the xenon ballasts, ignitors, bulbs and levelling sensors.

 

[RedUn]

Would you not think it’s a engine temperature/coolant temperature fault?

As if the sensor is faulty and the car thinks it’s much hotter than it actually is then it’s preventing a start. That’s my theory anyway.

Do you have a obd dongle? Plenty of apps out there, you could read the coolant temp live to see if it is temp related?

 

[Babw]

Exhaust cam position sensor and engine coolant sensor replaced. Problems all gone and running better than ever. Love a happy ending.

 

[RedUn]

do you know which one it was? Or just assume both?

 

[Bing]

Sorry I assumed by your post saying its a common error that you'd eliminated it?

I’m not sure I know what you mean but I cleared the misfire code and it hasn’t returned.

What I mean about the ECT is that if it’s faulty then at higher temps it’s throwing the fault causing the car to misbehave.

I’ll check the ignition switch and light sequence tonight. Only now I realise these cars are getting Jon a bit as in the past few months I’ve replaced all the xenon ballasts, ignitors, bulbs and levelling sensors.

Glad you got it fixed

Out of interest, what made you swap out all the light bits - did they just stop working ?

 

[Babw]

Glad you got it fixed

Out of interest, what made you swap out all the light bits - did they just stop working ?

I had some water ingress in one of the lights and had a funny flickering issue, assumed it to be the bulb but new bulbs got rid of the orange hue however the flickering didn't resolve until I replaced ignitor + ballast. I did both sides as other side is also over 13 years old and I get to keep the old parts as emergency backup if necessary.

While it was at Porsche I got them to fully steam clean the underside, waxoyl, change the brake hard lines and replace some of the corroded brackets which included the light levelling sensors.

Hope your misfire issues doesn't pop up again

do you know which one it was? Or just assume both?

Honestly I didn't have time to get the issue isolated so it was just a belt and braces approach which has worked.