Operating Temperature

[jimmy3530]

Hi Everyone:

Just finished replacing the coolant tank because of a leak. What a job! Tons of information on the site to guide one through the process. Couldn't have done it without all of you!

New question? What is the correct operating temperature for a 2000 996 C4? The temperature gauge yesterday (after the tank fix) sits on the "0" of the 180. Kinda tough to say what the number is...I would say 200-205 or so. The needle is almost at the tick mark between 180 and 250. It just seems high to me. It was hot out yesterday though - high 80's over here in Washington DC.

Any guidance on this matter. I read that many people install a third radiator and I'm wondering if this is something I should do. Seems odd though that this would be something that Porsche would underestimate....

Thanks in advance everyone!

[Loren]

That sounds about right.

Still remember to clean to the front radiators of debris - that is most common cause of increased temperatures.

IMHO the only way to really clean the front radiators is to remove the front bumper (15 minute job) and clean both the radiators and the AC condensers in front of them. Covered many times here so do a search for some tips.

[bmohr]

i'm in the washington area too jimmy and have a 99 c4. Car always runs to the right side of the "0" in hot weather/stop and go traffic. Once up to speed it moves from that. Go ahead and get your readings if you like by using the coolant temp hack if you are interested. Otherwise clean the rads like Loren suggested and keep an eye on your front high and low speed fans to make sure they are operating correctly.

[jimmy3530]

Thanks for the information. I took a peak in the front intake areas and there are definitely some leaves in there. I've also pulled the coolant temp hack info and will play with that tomorrow. I'm looking forward to pulling the bumper off and sees whats in behind there.

[1schoir]

Thanks for the information. I took a peak in the front intake areas and there are definitely some leaves in there. I've also pulled the coolant temp hack info and will play with that tomorrow. I'm looking forward to pulling the bumper off and sees whats in behind there.

Do you have the link for the coolant temp hack?

Regards, Maurice.

[jimmy3530]

I just did a search for "operating temperature". You'll see it. I've copied the text below.

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. Same as 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.

I have yet to verify all these, this info was copied from wonderful people on PPBB!

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 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?

[1schoir]

Jimmy:

Thanks!

Regards, Maurice.