2006 Cayman S - "engine temp too high" warning?
 

New Cayman S owner.. and just had this happen to me:

While driving home, mostly all freeway and then some stop and go traffic (my commute is about 16 miles) I suddenly got the dash beep and warning with the temp gauge all the way to the right to 250 degrees. I stopped, let it cool off then drove home with the gauge showing about 180-190. It did jump to 200 then suddenly back to 180, a very uncharacteristic movement/jump.

Things I checked at home:
Checked coolant level - it was good
Checked oil level - it was good
2 radiator fans are working
1 passenger side vent is working
No leaks below or around engine area
Checked coolant sensor, snug and wires look ok (didn't check current)

I started it up the following day, idles perfect, warms up in normal time. I then drove a good 30-40 mins at speeds up to 50 and the temp gauge went up again to about 225 and would then go down to 175. It did the strange jump around another time, but then mostly stayed around 200. If it's just sitting and idling a bit it seems to increase temp but it never went back up and trigger the warning.

My thoughts are sensor? t-stat? and then water pump? Any advice??

It has 61k and recently had the 60k service tune up at the dealer. Thanks!

Without specific knowledge of that car, a quick and cheap diagnostic check to rule out a sensor is to get an infrared thermometer for less than $20 (Home Depot or Amazon).

Check the temp of the hose leaving the engine. If it tends to jive with what your gauge is telling you, it’s likely not the sensor.


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Hello and welcome to the forum! wilnj gave you some great advice to help eliminate the possible issue. From your description, it sounds like the thermostat is faulty. There could also be an air pocket from when the coolant was serviced, which could cause those temp. fluctuations. If you have a scan tool, you can plug it in and see live readings of the temp. In case it is the thermostat, take a look at the link below to a DIY tech article from our site on the replacement procedure. Hope this helps you a bit and best of luck!

https://www.pelicanparts.com/techarticles/Porsche-987-Cayman/09-WATER-Replacing_Your_Thermostat/09-WATER-Replacing_Your_Thermostat.htm

Thank you for the reply and link.. I have looked at it before to study the procedure.. very helpful indeed.. Thank you Pelican Parts!

wilnj, thanks for the reply.. and info.. much appreciated! Shop just called me to say the t-stat is the culprit.. all other parts seem to working perfectly..

Update & result:

It was indeed the t-stat that had gone faulty. I also had the shop put in a new coolant temp sensor as well.

A good 2 hr shakedown drive through the mountains didn't move the temp needle off the 175 mark. All good.. whew!

Not sure of the year or what else was changed but a water pump replacement would’ve been wise while doing the thermo.