Chris(MA)

That still seems hot, there are a couple of ways your engine could be running too warm. (assuming your water pump doesn't have impeller damage)

One is the thermostat is not opening correctly allowing cooler liquid to be exchanged in the circulating engine path.

Two is the cooling system is not dumping enough energy out to air to allow the thermostat access to cool enough liquid to pass through the thermostat.

It might be useful if you could take a temp reading of the coolant lines going to/from the engine to the radiators, maybe with one of those IR temp gun things, they are cheap at Harbor Freight, that would tell you if you coolant system is dumping enough heat out of the radiator path.

Pulling the thermostat and testing it in hot water is more hassle and at that point might as well put a new water pump and thermostat on while you have it apart.

JohnCA58

I would look for about 10 to 12 degree's F drop between the inlet and outlet of the radiator with fans on, and normal load on the dyno.

ejdoherty911

I think your car is running hot at 104 C - 220 F. My temperature gauge does not go that far to the right even when hot on a hot day.

Volkert

And what was the outside temperature?
What does it mean "the fans were working"? With AC on the fans should both run at low speed (that still is a lot of air blown away!!) all the time. If the temperature goes to 107C they should go to highspeed and cool down to 104C.
With the normal thermostat it will only be fully open at 99C. So 100-102C is not strange IMHO when driving spiritly..

dedens

And what was the outside temperature?
What does it mean "the fans were working"? With AC on the fans should both run at low speed (that still is a lot of air blown away!!) all the time. If the temperature goes to 107C they should go to highspeed and cool down to 104C.
With the normal thermostat it will only be fully open at 99C. So 100-102C is not strange IMHO when driving spiritly..

Bash Hat

I still don't think you have a problem. During regular driving the car runs around 180 but gets a little hotter with spirited driving uphill in warm weather. Mine does the same thing and I have a new water pump and low temp stat. I think it's a function of these cars and possibly the amount of distance the coolant has to travel to do full loop of the cooling system it takes a while for the temp to cool down.

dedens

How warm does your car get? Have you used the console 'Hack' (Recirculating & Air up buttons for 5 seconds) to see the actual temp?

Bash Hat

Haven to done the hack but I will now that I know about it. At freeway speeds the needle is right at 12 o'clock. Stuck in traffic or going uphill in the canyons spiritedly it slowly gets to the "0" mark. A couple weeks back it was 115 degrees in the "valley" of LA. I was stuck behind a minivan going 15 mph uphill for approx 20 mins. Gauge went just past the last white line. Was about to shut it down but then crested to top of the hill, picked up speed toward Malibu where the temp dropped to 75 degrees. Car came back down to 180 pretty quickly. Here in LA there can be 40 degree differences in temps within a 20 minute drive. The pics were taken 36 miles apart!

Volkert

The suggested LTT is fine and I found general consensus that it makes sense to get it installed.
Difficult to judge of course from a distance but my observation would be that your car is still running relatively hot. Although the LTT will help in offering more cooling volume more quickly once fully open (so >180F) it will not make a difference anymore.
Another general consensus is to replace the waterpump at a certain interval. On my car it was 19 years old so I opted to get it replaced even if it still worked fine.

With LTT, new waterpump, rads cleaned, coolant flushed and fans running as they should your next option would be to replace the rads themselves and/or place a 3rd radiator to add cooling capacity.

dedens

Once again,. Thank you for the input. After looking at the cost of parts....New fans, water pump, and thermostat I have decided to sell the car....

Just kidding...

Actually I broke down and ordered the Durmeteric enthusist version. Figure it will come in handy and really isn't all that expensive compared to buying parts I may or may NOT need.
I will post updates in the coming weeks.

dedens

Durametric cable arrived today. Plan to download and configure the software this week. I will post results this weekend.

Volkert

So just a thought, we are all hung up on the coolant temperature, since it serves as a proxy for oil temperature. So is there a temp sensor for oil in the engine?

porschedog

^+1 what he said

(the temp hack is cool and new to me - I'll try it tonight on the drive home. Thanks for posting it!)

Volkert

I copied this from HRG / Pistonheads post.So 1c is oil temperature? I read somewhere else this is measured from the oil level sensor?

The AC Climatronic unit is actually manufactured by Audi. There is some sort of serial data stream (not CAN) that allows the AC unit to display engine parameters. This works on 1997-2000 boxsters/996

To switch from F to C:
Hold down the recirculating button then push both the temperature + - buttons.

To access diagnostics:

Hold down the Recirculating & Air up buttons for 5 seconds. The + - buttons go up and down through the list of "c" codes. The center vent button switches the left display between the "c" code and its actual value. Press the Auto button to exit.
Here is a list of what can be seen:

0c - ERL
1c - Oil Temp?
2c - Inside temp. Sensor mounted in the aspirator assembly at the side of the dash.
3c - Outside temp. Sensor located inside the air inlet of the A/C unit.
4c - Outside temp. Sensor located in front grill of the radiator. The data is fed to the Climatronic from the instrument cluster. When not moving, the instrument cluster OBC temp display retains it's last setting until moving. This is to prevent heat emanating from the radiator affecting the temperature sensor. The A/C unit uses the lower of the two outside air temp values in determining fresh-air temp.
5c - Outside temp. (matches with OBC outside temp display)
6c - Coolant temp.
7c - Footwell discharge temp.
8c - Sun sensor (dash top)
9c - Sun sensor.
10c - Passenger compartment fan speed.
11c - Passenger compartment fan voltage.
12c - Temperature mix Flap command 1=COLD, 100=HOT
13c - Temperature mix Flap position
14c - Central Flap command
15c - Central Flap position
16c - Footwell/Defrost Flap command
17c - Footwell/Defrost Flap position
18c - Recirculation Valve command 1=OFF, 100=RECIRC
19c - Recirculation Valve position (feedback)
20c - Vehicle speed in kph, updating only once per second. (real speed, not speed+safety margin as in the speedometer)
21c - Engine RPM in hundreds. This too only updates once per second.
22c - ?
23c - ?
24c - Sun sensor, exterior lights switch & panel lights control (term. 58 & 58d voltage) - used for A/C panel display illum.
25c - ?
26c - ?
27c - ?
28c - Fan speed?
29c - ?
30c - Engine run time in seconds (255 max.)(=0xff)
31c - Timing counter
32c - Displays test
33c - Software version? Mine states 3.4
34c - ?
35c - Outside temp. from inlet sensor (filtered?)
36c - temp?

AnthonyGS

After seeing this thread, I've been watching my temp closely here in hot DFW. My car doesn't get nearly as hot on the factory gauge. Now factory gauges aren't all that for perfect measurement but I'm getting up to about 190-195 max which is what most modern thermostats are set at.

Ive been daily driving mine in all sorts of traffic and heat since my wife's SUV was stolen recently. The 996 should go back to fun only duty soon.