Hatzenbach

I posted last year, that during a track session my oil temp went to 265 F before I called it a day
The feedback was to:

• enlarge the hole in the bottom of the underbody so that the air from the 3rd radiator can escape better (done)
• remove grills in front of the radiator (done)

Yesterday I was in stop and go traffic at 70 degrees outside temp and my oil temp went up to 215 and water temp to 210
As soon as I started moving at normal highway speeds again, the temps dropped to 192 (oil) and 184 (water)
I pulled over to verify that the front fans and the engine fan were running (they were)
The temps were measured directly from signals from the CAN bus, the readings on the instruments in the cluster were actually higher.

OK, now I'm out of ideas.

• water pump?
• what else?

rtl5009

it’s normal to spike oil and water when not moving. No real way to cool it.

Do you have a 3rd radiator and a low temperature thermostat?

when’s the last time you changed your coolant?

what ratio coolant:distilled water do you run?

have you cleaned between the condensers and the radiators?

have you sprayed out the radiators to remove all debris?

Bruce In Philly

2009 C2S 190K miles

Yea, Rob may be on to something with cleaning between the condenser and radiator. I did and it made a definite difference here in Atlanta. I was actually surprised. So much so, that I ditched my plans to add the third radiator. I cleaned the same on my 2000 Boxster S after about 194K miles and it made no discernible difference even though it had way more caked in debris than my current 911.

Here is my cleaning instructions: https://rennlist.com/forums/997-foru...l#post18221607

Peace
Bruce in Philly (now Atlanta)

My 2009 C2S at 180K miles and removing this did make a difference.





My 2000 Boxster S at 194K... that stuff was caked in there like cement... made no difference.

Hatzenbach

Thanks for the suggestions

• Yes I have a 3rd radiator
• No I don't have the low temp thermostat, but I don't see what good it would do here
• Yes I cleaned the radiators front and in-between, but there wasn't much dirt there to begin with
• ratio coolant / water: 50/50

Kitc2246

265 is normal for my 2013 Boxster S with third radiator. That said 981s, especially PDKs run hot. Once I hit 265 in the summer I start paddle shifting early. Was told by a tech who works for a race shop that does 981/718s not to worry about 280. Apparently 280 is normal for GT4s. Clubs Sport see 300. He said to change fluids, engine, PDK and diff more often. Unless the PDK goes into limp mode not to worry about the oil temps or additional PDK cooling. The water temp sits at 194. Oil temp drops like a rock during cool down, so for the 981 PDKs the heat exchanger is the weak link. You can install the larger heat exchanger from a 911 Turbo. (?) Earlier car was a 987.2. It didn't overheat but temps start to be higher. The radiators were full of fine dust and sand from the track. Cleaning them solved the problem.

rtl5009

I would do a LTT, the stock one does open fully until 210 degrees. Try it in almost boiling water for yourself!

Change your coolant too- you can also bring that coolant to water ratio down. Water cools best. test in own freezer. 3:10

Mike Murphy

This part is normal.

ADias

Note that the OP's ambient temp was a mere 70F... something else is going on; I would have a dealer look it over.

Hatzenbach

Thanks, yes that's my concern

roadie13

The suspicious thing to me is that you got any increase in the instrument reading for the water temperature. As far as I understood, that gauge does not move regardless of water temperature unless it really overheats; at least on my 997.1 that gauge never moves from the center position, regardless of oil temp, even on the track.

And since I got the third radiator the car never gets hot just standing in traffic.

Mike Murphy

Please keep in mind, an engine can overheat in -40F ambient temps. An engine only cools when there’s airflow across the radiators, and in stop and go traffic, there is essentially no airflow unless the fans are running. Many engines don’t turn on the fans until they are needed. With a 996, the first turn-on temp is 97C, well above 200F. I don’t know that much about the 997 and temp set points, but generally speaking, 100C or 212F should not be worrisome on just about any vehicle.