quickster2

Occasionally getting a Temperature Display Defective message as the car warms up while driving. Sometimes it also throws the following DTC: P3081 Eng. Coolant Temp. Implausible. When I get the display message I just restart the vehicle even while driving and the temp climbs normally thereafter. The temp seems to be stuck going back and forth at 150 degrees as I speculate the thermostat is opening and closing. I have to reset the DTC with my iCarscan when this occurs.

Any ideas or suggestions? Thx

deilenberger

I think monitoring the output of the engine temperature sensor(s) when this is happening might give a clue. You should be able to do that with the iCarScan. If the sensor value is fluctuating - I'd think a bad sensor or bad wiring. If the actual cooling system temperature is stuck at 150F - it points to a defective thermostat. That's a bit of a project (and probably a good time to replace or fix the thermostat housing with the glued-in pipes.. and probably do a water pump while in the area.)

quickster2

For further clarification once the car is restarted when this occurs the temp seems to climb as one would expect. I am leaning toward a bad sensor or an algorithm within the DME that expects the temp to be climbing and times out. It happens more frequently in cold weather and rarely all through last summer. The thermostat does not seem to stick as I can see it functioning on the display in the EVIC as this is one of the modes I have selected to display along with voltage and oil temp. At operating temp there is a mostly constant 201 degrees displayed.

I don't know how to monitor the sensor with the iCarscan will have to educate myself on that.

Thx for the reply.

deilenberger

The thermostat on the S V8 has some DME control besides the normal wax pellet - the computer will purposely run the engine hotter in order to increase efficiency. Wonder if somethings going on with that? You probably can also read that with the iCarScan - look under data-streams..

quickster2

Update looks like the t-stat is opening too soon and not modulating properly. Luckily it is misbehaving in the open position and not closed. Will most likely go for new t-stat, housing , and water pump. Get it all done whilst in the area. Thx for the replies.

quickster2

At the dealer diagnosed with faulty thermostat confirming suspicions. New T-stat, updated housing, water pump, and serpentine belt out the door for a little north of $2K. Hopefully this is the last item I have to address on this PiG for a while. Thanks for the replies on this thread.

Again, I have a nice new Macan S loaner. Great little machine. Just too small for road trips and baggage.

2011_Cayenne_S

Hey guys...

I have exact same issue it happened once today ...

I'm ordering new thermostat and pump ... not replacing housing ( I pinned the pipes while I was doing the back coolant distributor )

how many KM on the car.

does anyone know if Geba is OE pump ?
thx

quickster2

78,000 miles on my PiG. I am getting new housing as much for the new coolant pipe attachment scheme but my dealer said that the thermostat rides up and down in the housing and wears. Their normal procedure is to replace the housing when replacing the T-stat FYI. So.....new T-stat with updated housing/coolant pipes as well as water pump and serpentine belt.

2011_Cayenne_S

I will see condition of it once I open it... and decide if necessary, hopefully I can avoid it as I had just intake removed to fix the coolant pipe at the back.

thank you for the info

2011_Cayenne_S

I wonder if they will replace temp sensor as well...

I'm not 100% sure that it is thermostat in my case.

did your problem go away when you restarted car?, how often it occured.

thank you

quickster2

Yes my problem went away when I restarted the car even while driving which became the norm at the end. Occasionally, it also threw a CEL with DTC P3081. All good now after the service picked the PiG up yesterday. They did not replace the sensor. They were able to determine a bad T-stat. Water pump and serpentine belt were preventive maintenance as I plan to keep the truck for many years. Double checked and coolant pipes are clearly bolted in now with new housing.

Elberoth

Do you need to remove the front of the car to replace the T-stat housing and a water pump ?

ndx

No ... drain coolant
drop belt
remove plastic wheel
and pump and then thermostat ...

but I spoke with our EXPERT PTEC and he said that failures are not common on 958.

I'm having same code but most likely due to air bubble after doing the fix to leak at the distributor

13GTSNY

So I just got a 13 GTS and I noticed my temp levels staying below the 150 range and the car takes a good 20 minutes or so to even reach that in 40 degree weather. Today I got a check engine light and a warning that my coolent is low. But I’m topped off and I heard my radiators kick in. Turning the car off does do a bit of a reset but the check engine stays on. I scanned the car through the OBD and got the p3018 code. Has anyone else come across this issue?

quickster2

See post #11 same code.