My Cayman hates traffic

I monitor temps in my 2008 2.7 Cayman with the Torque app and generally it runs around 183 to 186 range for most driving. The thermostat and water pump were replaced with the coolant caps and a third radiator added within the last 10k miles. Occasionally, and now much more frequently when sitting in traffic it will start to get too hot. Up into the high 190 too hot. When I checked the coolant level it was down a few ounces but not anything significant, the pump shows no visible leaks, grinding or end play. So here is the interesting part with my Durametric I can activate the radiator fans but they will only spool up for a few seconds and then shut down. Does this indicate an issue with the fan control module? Is there anyway to trouble shoot these? I can run the engine compartment fan and smog pump through the Durametric until I turn it off. Anyone have experience to share? The other weird thing is my parking lights do the same thing?!?

Your parking lights get way too hot? Or just come on for a bit? I'm confused. As far as 190F - that's hot but not excessively hot. It's only 4F different from your normal running temps - that's not enough to get excited about. I'd be chasing it IF it exceeded 200F or so. BTW - where are you located? Obviously ambient temperature will change the efficiency of the cooling system.

By high 190 I mean almost 200. Luckily traffic started to clear and temps recovered before things really got out of hand. When I test the parking lights with the Durametric they will only flash for a second and not stay on. Located in the northeast and ambient temps have not been enough yet that this should be a problem.

OK. When the thermo and water pump were replaced did you use factory parts? And who/why was the center radiator installed? Was overheating an issue before? Small Edit: On thinking about it - Porsche and many other manufacturers control the engine coolant temperature to maximize efficiency. It's certainly not uncommon for my Cayenne to run very close to 200F (with the oil at around 210F.) I wonder where the overheat light is turned on with a 987.1 .. anyone know? As far as the parking lights - do they work normally when turned on normally? If so I think that might be a Durametric problem, not a car problem. Your 987.1 does still use a electro/mechanical relay circuit for the front fans, and I'm not sure which controller turns that relay on. Starting on the 987.2 Porsche went to a solid-state variable speed front fan controller. Yours I believe just has high/low speed. And the center radiator isn't going to do much cooling at urban traffic speeds, not enough air passing through it. EDIT2: When is the last time the front bumper was removed and the AC condenser and radiators cleaned of debris? It's amazing how much can be trapped there, obviously degrading the cooling performance.

190F isn't even CLOSE to hot. You've got a 50-50 coolant mix and a 20 psi cap: it's not going to boil until like 230F or more and the light doesn't come on until like 225F. Modern cars run hotter to increase efficiency, and I'm honestly surprised it's even that cool. You really do not have an issue.

I question this because I haven't seen the car get above 194 in traffic which is supposed to be the point which the fans turn on.

NY are you running a front plate as per NY law? I'm asking because it could be relevant depending on whether it changes the normal airflow.

I'm confused. You're questioning what? That the fans don't run although the car hasn't gotten to the temperature where the fans will turn on? Or that Durametric only turns the fans on for a few seconds?

I think you are OK . Should be similar to the 987.2 , 183-190 ° while casual highway cruising @ 75 ° ambient. Temps after heat soak in stop and go traffic will easily walk between 200-210 °. Fans seem to kick on at about 200-205°. If you start seeing temps over 220 ° , you should have concern. But as @gubi stated above, 190 is relatively chill for a modern car, and they are designed to operate in the full range.

I have a curious nature, I question lots of things. Appreciate the reassurances that I am not at risk yet and it would be very helpful if that factory gauge wasn't such a liar. Trying to keep the car running as cool as possible to avoid thermal stress and maintain oil pressure and integrity. For the last few years I never saw temps above 194 in traffic. Always assumed the fans came on to stabilize the temp traffic cleared and I went on my merry way. Yes, also questioning why the fans won't keep running in the Durametric test module. Everything else from the headlights to the horns stays on until you turn it off. With the exception of the Parking lights but that might be understandable since they are an LED experiment. Rethinking all of this I did swap to a 5w50 last year and that is when I started noticing the higher temps. The real shame is the USPS lost my used oil sample before it could get to Blackstone to be analyzed.

Thicker oil will run hotter, yes, so if you saw a step change that could be the reason. Could also be you've got some buildup in the radiators between the condenser and the rad, though that requires removing the front bumper to fix. I've cleaned that a few times and never really found much in there myself. But, yeah, nothing's going to get hurt at the temperatures you're reporting.

My 2016 Cayman 2.7L 6MT runs at 194 deg all the time independent of outside temps. It is run in the summer in CO where temps range from 40-100+. Oil temps run 210-230 depending on the type of driving, but water temps don't vary even one degree. You are worrying about a non-issue.

I haven't monitored my 2008 CS in a while, but remember seeing 186 as normal and easily seeing mid 190s when stopped at traffic light. I seem to remember that with the A/C on the temperatures actually rose less. Maybe the computer is programmed to give the car more headroom to heat when the A/C is on. On hot days, particularly after parking for a while and then running the car, the engine compartment fan will come on.

I'm not sure about the 987.1 series - but the 987.2 series has a different set of fans and controllers. On the 987.2 above a certain temperature, if the AC is on, the starboard side fan runs on slow speed (until higher speed is needed) continuously.

Its doesnt vary because that is a fake, buffered number, All 981 models stop and hold at 194F despite the fact that the actual water temp if read from the OBD port is higher than that.I guess Porsche got tired of people worrying about the temps and bothering them about it, so they dumbed down the gauge for the masses. Only after the actual water temp goes above 230F/110C will you see the value change as a notice that things are getting too hot. That tells me that they consider anything under 230F water temp normal operation on a 981 model.