The 944 gremlin strikes again! So I have been struggling with overheating problems but after a good “burping”, a new expansion tank cap and some major repair on the aircon it finally looked good. The overheating seems to be at bay but then…..While taking a Sunday evening drive ,aircon switched on, cruising through the streets sipping a refreshing coke my eye suddenly caught the temperature gauge bouncing at the end of the heat gauge……the gremlin returned! After inspection it seems the high speed fan was not working, while sitting against the road sipping my now warm coke to cool her down I saw all the people looking at my broken down “Porsche”. After a few started her up ,aircon off and drove her home without any problems. Now being very pi$$eed I lock her in the garage ,but after two days I took her out again for repairs. Started her up and for fault finding switched the aircon on to trace the fan problem but guess what suddenly everything is working fine, the fan is suddenly running again .
So please ,any help on what to look at, I really do not want to lose a head gasket over this!

 

IM HAVING THE EXACT SAME PROBLEM! Mine will run all the way to red and overheat or blow a radiator hose. I do nothing to it and its fina again. Only once in a blue moon. AC makes it worse. Ive already replaced the thermostat also.

 

Have you thought about the radiator fan switch being bad or its wiring? You know the one that screws into the radiator that controls when the fans come on.

Cheers,
Larry

 

Spend the money. Replace all hoses, the radiator, fan temp switches, thermostat, coolant tank (you did that), and you will be good to go and never overheat.

Years of crap can build up in the radiator and people think going with the lower temp fan switch is the way to go. All that does is more wear and tear on the fans. The radiator is strong enough if it's clean. I recommend just getting a new one.

Oh and replace the fans and fan shrowd. If you have the cash.

 

Lets not forget the pesky little relay, it's a combo deal 2 in 1, controlling the fans...

Next time your fans quit.. try tapping on the relay to see if they start up.... if so bite the bullet and order a new relay...

http://www.paragon-products.com/prod...615.104.03.htm

 

make sure all of your hose clamps are tight. If they arn't, then the coolant system won't hold pressure, and run hot. generally this is accompanied by a loss of coolant.

 

Whatever you do, remember that the cooling systems on early cars are differently set up than late cars.

 

i like the idea of big oil coolers because in theory, they would give you more flexibility if a problem develops, to discover, diagnose and correct the problem, as a serious event actually unfolds.

of course I am too lazy to go out, research, and fab the plumbing to connect a large unit and then, properly fit it in the car.

so how 'bout you-all ?

 

Thanks guys
I think i am going to replace the Relay and the Fan Temp Switch to make sure!
I have ordered a thermostat so that will be on the next thing to do list.
What temp fan switch do you suggest?

 

Do you have to pass emissions?

 

My S2 started running hot at road speeds one day and I found it was a spun water pump impeller.

-Joel.

 

"Do you have to pass emissions? "

No not in South Africa

 

The Gremlin is at it again!
So I took the car out to repair(fit relay and temp switch).On the way to my workshop to do the work I test everything again ,both fans switch on at temp and also if I switch on aircon,so everything is working as it should. I stopped switched off the car, got out but then I notice that the high-speed fan are still running. I eventually took the battery off ,as it just won’t switch off!
So what do you guys think is the problem, any advice will be appreciated!
I did not replace the relay or switch yet.
If it is the relay,where are it situated?
Thanks
Vic

 

I think it's normal for the fans to sometimes run for a while after you shut the car off. Pretty sure my car does that, anyway.

 

I recently went through some overheating woes with my 84 944Cup car.

With regards to the thermo switch on the radiator that runs the fans, note that it runs on a timer. If it has just come on before or immediately after you turn off the engine, it will run for several minutes. I had one that would randomly not go off, and was mysteriously killing my battery until I paid attention to its cycling.

The other thing that stumped us for a while (rebuilt motor had recently been installed) was that both fans were wired backwards. So the car would actually run fine until the fans came on. Then air coming in at speed was being pushed back out by the fans, and a dead zone of air resulted around the radiator causing the temps to rise. On early 944's, the fan wires are a paid of spade connectors that plug individually; so easy to swap the wires by accident. I believe later cars had a better 2 wire plug, that could only go one way.

The backward fans were baffling to us, because the car would run fine in the driveway/garage/paddock. It was only at speed when the problem would arise. It was discovered while burping the cooling system, and one person happened to be standing in front when the fans kicked on, and he wondered why his legs were suddenly getting warm.