New Boxster (and Porsche) owner here, about a month with my 987.1 BS.

I have been surprised how cool it runs. I have gotten used to modern cars running at 200+ °F (for "efficiency"). So to see the temp gauge at 175 or so is quite a shock.

I would not be in the least bit worried with any engine running at 180-200. For an everyday vehicle. run "normally" or even "spiritedly", unless you're seeing well over 200°F under "typical" (under 100° ambient and "just driving") conditions, I wouldn't bee the slightest bit concerned.

OTOH, if you have had the car for 10 years, are very well aware of the historical "behavior" of the engine, and are seeing statistically different readings, that's a whole 'nother story.

Coolant temp sensor is located right where the fluid returns from radiators, so it is basically the coolest point and coolant would be a lot hotter at head or oil cooler... This is why people pays special attention to be safe.

I've done this too. My car sits on the rightmost edge of the 0 in 180 in hot weather in heavy traffic, but will go down if I turn on the AC.

The low temp thermostat is a good idea IMO (haven't done it yet myself), but I suspect it won't help lower your coolant temps - just delay the system's reaching max temperature. I actually noticed my temperatures go down a bit after cleaning my radiators. 3rd radiator is probably the best permanent fix, if you think it's a problem to begin with.

Geez, dont know why it hadn’t dawned on me early. Just turn on the AC. And as many pointed out here, the low temp thermostat doesn’t really add to the cooling capacity. Just begins the process a little earlier. Am thinking now that the S oil cooler is the first order of business. That should add cooling and not as expensive as the 3rd radiator.

Slightly different issue with my 2002 S. The mechanic during an inspection told me the engine fan ran when he put power to it, but that it didn't come on on its own. The gauge reads just a little right of 180. Anyone have any ideas why it doesn't engage on its own?

Thank you.
Bill...

By putting power to it does that mean jumping relay?
Turning AC on will telll you if low speed operation is working

resistor for fan under front bumper

whoops, you mean engine compartment fan. I agree sensor may be shot as mentioned below

Engine fan in the engine compartment? Then the temp sensor on the intake manifold may be shot or not wired right? If you meant radiator fans, then likely those registers as mentioned earlier.

I drove it today before reading about the idea to turn on the air. When i drove it, the temperature never got past the 8. However, when it was idling on a warm day a couple weeks ago it did spike up a bit higher. I'll reach out to my mechanic and share your feedback below. He has been working on these Porsches for years and hasn't seen this issue where it didn't come on. Just trying to understand how these cars typically run as this is my first one. Haven't had any issues since it only has 16K miles. Just got it, everything else checked out perfectly after a 4 hour inspection. 16 years old and its like going into a time machine. Even still smells new. Really appreciate all the feedback. Thank you !!

quote: Engine fan in the engine compartment? Then the temp sensor on the intake manifold may be shot or not wired right?