924Board.org

Smittyrock · Joined: 17 Mar 2004 Posts: 1 Location: AZ

I have replaced my thermostat, the radiator is working, so is the water pump, but my porsche still runs hot, my fan wonm't come on till the temp guage is pegged, and it's not too too bad driving bad at an idle it runs straight hot. I have flushed the radiator, and taken out any possible air bubbles, it circulates the anti-freeze, but still gets hot as hell, what is the deal? What can I do? Please can someone help me?

Justin Smith

D Hook · Joined: 02 Nov 2002 Posts: 3158 Location: Omaha, NE

Thermofan switch located in upper driver's side corner of the radiator. Large screw-in-looking thing with two wires going to it. This controls when the fans kick in. You can buy a new one that will have a lower temp so the fans kick in sooner.

When the fans finally come on, does it bring the temp back down? How far before the fans cut off again?

Also check the grounds under the dash and the plug into the back of your temp gauge on the dash cluster. Sometimes a bad connection will give a higher/lower reading. Is the radiator boiling over into the expansion tank when it gets that hot?

Got the thermostat in the right direction?

Did you follow the bleeding procedure in the Haynes?

Last thing to try is to pull the radiator and have it cleaned/rodded out or get a new/used one.

I've done all the things that I've listed above to mine, including the water pump, and mine seldom gets above the center mark anymore. Used to get into the red before the fans would kick on. I had the radiator rodded out a few years ago. Cost was about $75, I think. Cheap, if you pull it yourself and take it in.
Good luck and keep us posted.

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

I had the overheating problem when I got my car.

I changed the thermostat to a lower temperature version and the thermo time switch (screwed into top corner of radiator) to a lower temperature version. My car now stays a the 1/4 mark where as it used to always touch red.
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1987 951 - M193 Version for Japan

augidog · Joined: 03 Mar 2003 Posts: 1360 Location: New Jersey

The red line is always scary.
If your fan thermostat is working-- it sounds as if your overheating the engine and then it catches up to the radiator and sets off the fan.

An old trick is to pull your thermostat out completely to see if it is the problem.
I think this is possible to pull it out while still retaining a good seal, but you may have to ask. I have not changed mine in awhile and forget how the o-ring lays in.

If this does not help then maybe the pump is not circulating, as it should.

I know that in a closed heating system the water will re-circulate by gravity alone.(hot to cold)
I don't know if this applies but its something to think about.
I was told from day one on this board (don't overheat your head)
Good luck
A new radiator cap never hurts.
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1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

Smoothie · Posted: Thu Mar 18, 2004 12:42 pm Post subject:

Not good to go without the thermostat. If you look at pg 59 of the Haynes where it shows the cooling system flow, you can see that if no thermostat or the wrong thermostat is used, the coolant will get routed from the top of the engine, through the water pump, then right back to the engine lower down without going through the radiator. A thermostat and the correct one with the extra disk at bottom is needed to direct the flow through the radiator when the thermostat opens.
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

augidog · Joined: 03 Mar 2003 Posts: 1360 Location: New Jersey

Thanks Smoothie ,
I was not sure.
_________________
1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

82-924 · Joined: 30 May 2003 Posts: 75 Location: Long Beach, CA

To Smoothie or anyone else who knows: Regarding proper thermostat for 924 that has the extra disk mentioned above. Where do I get it? From Porsche dealer?

I bought a thermostat from autozone some months ago. I don't know if it had the extra disk or not. I am now in the process of replacing the head. I obviously want to avoid this in the future. Ensuring I get the right themostat this time might be the way to go.

Smoothie · Posted: Sat Mar 20, 2004 1:00 am Post subject:

I got one just over a year ago from www.thepartsbin.com - with a minimum order of $50 shipping's free to the 48 states.
Here's a pic of the old one and the box that the new one came in - both old and new have the disc at bottom. I got the lower temp 82 degree C version - part number 059.121.113B (thepartsbin# G4000-13853).
Made by "Gustav Wahler GmbH u. Co.KG."
The o-ring for it is ordered seperately and that's 059.121.119 (G4030-13854).

_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox