I have a 2001 996 C2 that is running a little hot. In traffic, 85 degrees ambient temperature, I will run 103 C or higher at times. I have been using the HVAC head unit to monitor the temp. I recently bought an OBC reader (ELM327 WiFi) and installed ODB Fusion on my iphone 5. The OBC reader is reading about 3 to 4 C less that the HVAC display. Why would they be different and which one is the accurate reading? Am I reading two different sensors? Thanks for your help.

 

I don't know about NC, But in Colorado we use F as a temp. What is that in U.S. measurement? You might be perfectly fine. Start, if you haven't by cleaning out your fan intakes.

 

according to your manual, you have nothing to worry about until the light is red. mine runs north and south of that 3rd line your looking at. depending on ambient temp, load and ac. I had an air cooled too and these cars can run hot. this isnt your passenger car.

 

The way I understand it, when a 996 is running right, the needle should be between the 8 and the 0 on the "180" on the guage. If your guage is marked in Centigrade this means you are running north of 212 (boiling) on the Farenheit scale. This does not sound like a normal running temp to me. I live in Florida and with a/c running, the needle sometimes moves to the outer right edge of the 0 on the 180 mark. I just had some extensive work on mine to eliminate coolant leaks and I've been running in that zone ever since.

 

Everyone's gauge reads different. They are imperfect and not right on. These cars do not love the heat and it is important to keep them as cool as you can. I mentioned in a previous post, in temps like NC and Florida with little chance of a deep freeze, I would run 70% distilled water to 30% Porsche coolant. Since we have such a large quantity of fill required, I also recommend TWO (2) bottles of Red Line Water Wetter. I did this after pulling my bumper, and PULLING APART the radiators to clean in between and with a brush to make sure all fins can cool There was so much stuck in there I could not believe it. Cig butts, embedded dirt, etc.....that you cannot get out by surface spraying no matter how hard you try. It is a big job, but worth it. I normally run in the center of the 0 on 180, but when hot or in slow traffic it will go near the 3/4 hash and the fans will kick on. This car needs the air flowing over the radiators to stay properly cool. When I pull a hill it kicks up near the 3/4 hash, and to the left of the 0 on they way down the other side. In traffic, I've read to turn on your A/C if your car is getting hot. This kicks the fans on high in advance of getting too hot...regardless of temp. I've also got an LN Engineering 160 T stat, but this is of no help when it is wide open on a hot day....just keeps it cooler longer. Good luck and keep us posted.

 

Let me chime in a little I'm in Fla, mine stays right on the 8 in the 180 mark unless I run her hard then she goes to between the 8 and 0, as mentioned everyone's guage is different so you're fine even just above the 0. But I would clean the raidators, check to ensure the coolant is up to snuff, in fact a dealed can flush and change coolant for about $100 bucks.
If you temp goes too high you could have a pressure leak, bad sensor, bad coolant, or a bad radiator.

 

Mine goes past the "0" mark when I punch it sometimes but when I lay off the gas and cruise for a bit it goes back down again

 

Las Vegas 110+ F, between the 8 and 0. Normal stop and go traffic with A/C moves on to the 0.