Coolant Temperature Sensor/Sender replacement....

'07 2.7 Cayman w/ 41k. My temperature gauge is jumpy and flashing "temp gauge failure". When the engine is up to temp, it is OK. I have ordered a sender, clip and o-ring. I was under the car doing an oil change and could not see the sender. Not much info on this from a search. Is this sender accessed from under with the most rear plastic panel removed or is it from inside behind the seat? Also, can I change it out (cold) without draining the coolant? I hope a careful pull it out, stick finger in hole and replace with new sender approach will work. I've read how difficult coolant draining/filling is... Thanks, C.

Searching the articles section in this forum, the Cayman Registry, and RennTech.org for "how to" may be useful in doing this. If no one has written an article on doing it for this site, then if you do tackle this, consider photos and then documenting your efforts for an article. Good luck . P.S. Folks have done just about everything on the 987, so if you have the right tools and decent instructions, most jobs are pretty doable.

I did this job and it was quite easy but I may have screwed up. Doing the swap, I did loose a little bit of coolant; I would say 2 ounces. The level in back did not change and in fact looked like it rose slightly. I suspect a bubble but I thought it was worth running the car to see if it worked out. The coolant level has never really dropped. It's not high anymore but I expected to have to add some coolant. Looking back, I should have loosened or removed the cap (s) so coolant ran out freely during the swap, then I wouldn't have drawn air in through the sender hole (the sad part is I thought of this and forgot to do it). What would be the best place to remove a line up high to check for air or add coolant? Gauge is working properly now. Any help would be appreciated but please don't tell me to take it to the dealer. C.

What makes you think you sucked in air? If you only lost 2 oz of fluid, I wouldn't worry about it. Just check the level after you've driven it a while.

Because the level never dropped?? It's been a few days now and it's still at FULL. Whether or not this was the proper approach, it was fast, easy, the gauge works and the starting problems are gone. I did take some pictures and some notes about the sender disconnection and removal. I'll try to get something for the board this weekend. Thanks, C.

Here is a description of the sensor replacement and a couple pics: The Coolant Temperature Sensor is accessed from the panel behind the seats. I unlatched the hanger to free the wire and even unscrewed the hanger just to get it out of the way. The sensor is a smooth type fitted with an o-ring and a retainer clip. The release “button” on the connector was facing down so I just turned the sensor to face it up. You push the little button toward the wire leads and it pops right off. I put the new o-ring on the new sensor and put it where I could reach it when working. I also placed a curled pic with it in case the o-ring didn’t come out with the sensor. I removed the clip and pulled out the sensor. The o-ring stayed in the hole so I hooked it with the pic and removed it. I grabbed the new sensor with o-ring and stuck it in. Push in the clip and reconnect the pigtail. Replace the hanger, put the wire back in and close the bail. Done. I lost some coolant and it took several days for the level to fall when looked at from the filler in the rear. I’m not sure if that is OK and maybe the cap should be removed before the swap so coolant drains in a more controlled fashion and can be refilled from the fill cap . I lost only about 2-3 ounces.

It's not something that I would lose sleep over. The system holds about 6 gallons of fluid. 2-3 ounces is minimal loss, and after having driven it for a while any air pocket probably wound up in the rear by the filling cap . Just top it off, and you should be fine. On a long drive just be sure to monitor the temp gauge for in case something's off.

Two items I'd like to add to replacing the sensor and one issue I'm having. Let me begin by saying the pictures, instructions and other advice were very helpful, however let me add some suggestions. First, have a mechanics style magnet handy (the telescoping type that can reach 18 inches) you'll need when you drop the retaining clip. Second, be prepared to bend your hand like a contortionist or have a small pair a hands standing by to replace the clip. Now for my issue, after replacing the sensor and checking the fluid level, I started the engine and as it warmed up the temperature fault returned. Unless anyone has another suggestion, I'm thinking it's time to take it to the dealership.

clconroy: If you have a durametric then clear the CELs. It may take some miles for the ECU to cycle through the checks before the CEL disappears by itself.

I took your advice and after a few miles the temp gauge came to life but the CEL remained on. After stopping by Advanced Auto they were able to check the codes and found a P3081 (temperature fault code). They cleared the codes and I'm now error free. Thanks for you help.

i too, just changed my sensor. i lost about a quart of coolant ( i didn't expect it to shoot out so fast) i also dropped the retaining clip as well as the old sensor, but luckily it was easily accessed from under the car. i noticed the old sensor didn't have the old o-ring on it so i am not sure if it is still in there or it fell out somewhere. the new o-ring was on the sensor and it seemed to go in without too much effort. technically it wasn't too hard, but can be tricky to swap.

Crispy, great job thanks for sharing. In my opinion it's 50/50 leave filler cap on vs remove filler cap . Leave it on and you have a partial vacuum effect with minimal loss. Remove it and you have flow which doesn't necessarily prevent an air pocket in the circuit. I think I'd be inclined to do it with the cap on and after each each heat/ cool cycle open the filler and add if required until satisfied it's back at the correct level.

My sensor malfunctions intemittently. Wouldn't it be easier to access the sensor from beneath the car than removing the panel behind the seats and risking dirtying the interior or is the access from there too difficult? Also, I lost quite a bit of coolant (didn't have cap clicked right and caused a huge pressure that put about 1.5 gallons out through the overflow). I topped off with distilled H2O. Is this enough loss to bother to do a full flush or should I leave it alone? One concern I have is that I store it in an unheated garage in the winter and it's gotten down to close to -30F here historically, so extradilution is probably bad for preventing freezing and possibly for corrosion prevention as well. I anticipate a pretty unanimous reply to flush, but was wondering if maybe it will be ok.

Drain off a gallon of mixed coolant, and replace it with a gallon of new Porsche anti-freeze, and you'll be OK.

Thank you for the guidance, Crispy! I just finished the job, all is well. I'll just need to top off the coolant. OEM coolant in hand. :thanks:

Just swapped my sensor this morning. Great information here. I didn't lose too much coolant either. I placed a rag underneath the sensor to catch the spring clip and absorb the coolant. Worked well like that. My o-ring was also stuck in the housing, just grabbed it with my fingers. I used an Audi / VW sensor PN 06A919501A. Since it was $10 and available from my parts supplier (and they said it was compatible) A few websites also verify cross vehicle compatibility. On the sensor it says 140 degree max. Which I don't understand the reasoning behind that. All is functioning as normal. We'll see. Various google on the part numbers. CAMBIARE Part # VE375005 {#0135427817, 06A919501, 06A919501A, 1100736, 135427817, 1459209, 6M2110884AA, 95510612500, 95510612501, 99760641000, MN980152, MN980264, XM2110884BA} Switch, temperature radiator fan; Black top, yellow dot, 2 pin oval push-in conn., Radius: 20mm 997 606 410 00 | 99760641000 | 06A 919 501A / 06A919501A | Porsche Cayman Boxster Water Temperature Sender OEM Elth 99760641000 | New-Part.com

Where do I see the photos?

This is an old thread, but here is a link to a YouTube video. I did mine recently and it’s not too difficult, just tight quarters working on it. Like someone suggested previously, place a rag under the area you are working to catch the clip when you drop it. I should know. I dropped mine and spent another hour searching for it and fishing it out. Even though I had replaced it with the new one, I just didn’t feel comfortable knowing there was an errant piece of metal floating around under the engine.