HELP! Over heating - 84 944

[firefighter7128]

sooo, i have an issue. car runs at about 1/2 on the temp gauge, but if im driving it and get stuck at a long light, it will climb. then my fan kicks on and seems to bring it down ok. This happens more on hot days and ...its just going to get hotter. no water leakage so is it my water pump or is it my thermostat?
Where is the thermastat?

2nd, out of the 2 fans, one (left DS) comes on when the temp gets high. the other occasionally turns on and only when the car is running.

ideas? suggestions? its on jack stands now in my garage. im standing by waiting for replies.

[CJFusco]

That sounds normal to me. Unless I'm mis-reading the post.

[hpservertech]

Sounds like it's doing exactly as it should.

[firefighter7128]

um, when i say it gets hot, i mean hot! you smell it. i think its a irculation issue. or are these just hot blooded?

[hpservertech]

What does the temp gauge say in the car?

How does the heat work? First thing I would do is bleed the system....airpockets can be a pain.

[firefighter7128]

well the heat is constantly blowing into the car. thats another thread that no one has replied to yet. blows thru the vents as well as like fire down on the floor. makes it a deal drag to drive on a nice day. the temp gauge has gone as hight as..slightly past 3/4. theres no numbers.

[hpservertech]

if it was a late car I would say check the vent clip that always breaks. but can't help much with the early cars.

It does sound like you are overheating. I wouldn't keep driving it though until you figure out why it's doing it. could cause further damage.

Start with doing a flush/fill/bleeding of the coolant system. From there it could be the temp sensor not turning on soon enough or thermostat not opening up all the way.

[firefighter7128]

now a receipt that have from previouse owner shows they did a complete wash of the coolong system about a year ago. few new orings and stuff. so their may have been an issue then that wasnt corrected.

[CJFusco]

The vent clips break on early cars, too...

[firefighter7128]

and let me guess.... you have to cut the car in half to get to them?

[Tervuren]

Your temperature gauge and fans seem to be showing normal signs. However - the temp gauge is in the radiator. There is a valve that opens and closes between the radiator and motor - if its operating at too high a temperature, things aren't getting cooled properly - and there's gonna be a fair amount of heat in there.

Keep in mind, when the car is still, it does not get the cooling from moving air - hence the temp rise and second fan kicking in. If it spikes really really fast - up to the solid yellow, then you've got super hot water coming in all of a sudden.

My '84 had the same heat stuck on - in my case, the actual cable is frozen, I can close it under the hood, and it shuts the heat off. It will pull it to open, but not push to close.

[firefighter7128]

Originally Posted by Tervuren

My '84 had the same heat stuck on - in my case, the actual cable is frozen, I can close it under the hood, and it shuts the heat off. It will pull it to open, but not push to close.

what was the fix? or did you? my heater contols do nothing. one obviously has a bad cable. project #51960

[jpk]

Temperature guage on my early car was kind of flakey like that as well. It was never really overheating, but it did worry me at times.
One of the issues is that the guage itself is not dampened electrically, so it moves quite quickly. The guage reacts to temperature fluctuations faster than the cooling system can; for example, in a span of a couple minutes, you'll see the guage swing up from 1/2 to past 3/4, the fan will kick in, and the guage will go back down to 1/2. If it were dampened properly, you would never see that swing; it should take 2-3 minutes for the guage to move 1/2 the scale.
Make sure the system is bled of air; there's a proceedure (as well as troubleshooting) on Clarks-garage.com.
Make sure both fans work when they should. If you turn on the AC, one will kick on high, the other will cycle when the fan switch (in the radiator) tells it to.
As for the heater control, there's a valve inline with the heater hoses near the back of the engine. You can shut that manually to cut the heat to the interior.

[944Spec_bound]

I'm fighting a similar battle with the temp, so my only advice I can offer is to spend $20 on a infrared thermometer and leave it in the glovebox to tell if it's actually overheating or if it's the infamous gauge issues.

[firefighter7128]

Thanks for all the advice guys. I do know its over heating due to the smell.
Im flushing the radiator today. I know the timing belt was replacedin 2007 but i dont think anything else was. so im gonna look at my options.

[hpservertech]

You could also have a coolant leak somewhere. One of the hoses might have a crack or split that you can only see when it's hot. The coolant could be dripping on the hot engine and that's what your smelling. Best way to check for that though is with some coolant die and getting the car to run hot.

[smokin_944]

In actual fact your first post indicates a problem. On early cars (83-85.5) the 2 fans work independently one from the other. The first fan to come on is driver side. It comes on at low temp configuration as dictated by the value stamped on the thermal fan switch. The degrees stamped on the switch tell you when the fan will come on in low mode, and in high mode. No matter what, when the temp reaches the high temp condition, a parallel circuit triggers the condenser fan (passenger side) then both fans run at full speed. You have a fan problem. The 2 conditions for the passenger fan to run are 1) A/C is on or 2) the thermal switch has reached high temp. The problem on early cars is the fan problem could be relay oriented and most Porsche people don't even know which relay is responsible. Check the fan relay (4 pin connector) to see if it works. Pn 141 951 253 B. Keep us posted.