Boxster Coolant Mystery: Expert Porsche Help Needed

Hey there, I had a similar issue with my 2015 Porsche Cayman last summer. The symptoms you're describing match what I experienced, engine temp rising and coolant mysteriously disappearing. Initially thought it was just a leak, but turned out to be more complex. The wiring harness to the coolant temperature sensor was corroded, causing inaccurate readings and improper cooling system function. The dealer found several issues during diagnosis: corroded connections affecting the sensor readings, damaged insulation on the wiring, and some water damage in the connector housing. They had to replace the entire harness assembly and recalibrate the system. It was a serious issue that needed immediate attention to prevent potential engine damage. For Porsche-specific issues like this, I'd strongly recommend going to a certified Porsche specialist. These cooling system problems can be tricky to diagnose correctly, and a wrong diagnosis could lead to bigger problems down the line. Hope this helps with your decision.

Thanks for sharing your experience! That really sounds similar to what I'm dealing with. The corroded wiring harness issue is definitely something I'll have checked out. Do you remember roughly how much you ended up paying for the whole repair? Also, just curious, has everything been running smoothly since the fix, or have you noticed any other cooling-related issues?

Hey again! Yeah, glad I could help! I actually just had everything fixed up last month, the whole repair came to 155 Euro, which honestly wasn't as bad as I was expecting for a Porsche repair. The main issue was indeed that corroded wiring harness to the sensor that was causing all the trouble. Since getting it sorted, my Cayman's been running like a dream! The radiator shutter is working perfectly now, no more temperature fluctuations or coolant issues. It's such a relief not seeing that temperature gauge creeping up anymore. Honestly, it's like having a different car, everything's working exactly as it should. Just make sure you get it checked out soon, these things can get worse if you leave them too long. Let me know how you get on with yours! Always happy to share experiences with fellow Porsche owners.

Just wanted to update you all! Took your advice and got it sorted at a certified Porsche specialist. what a difference! Turned out my issue was pretty similar, faulty wiring was the culprit. Cost me a bit more, around 200 Euro, but totally worth it. Had to wait a couple of days for the parts, but the mechanic (guy named Mike) was super helpful and kept me updated throughout. He even showed me exactly what was wrong with the old wiring, completely shot from years of heat exposure. Been driving it for about a week now, and it's running perfectly. Temperature's stable, no more coolant issues, and the engine's purring like it should. Guess I was lucky to catch it before any serious damage happened! Thanks again for pointing me in the right direction. Nothing beats getting advice from people who've been through the same thing. Really appreciate all the help!