drohalloran

Hey guys, I have a question about the cooling fans on an '83 944: should the primary fan always be on? It seems like it should be, but mine only comes on after a certain point, then the secondary comes on once the car gets hot. Now with that said, my car is consistently running into the 3/4 hot range on the gauge. I have replaced the water pump, thermostat, fan switch (on radiator), both fans (which were bench tested and confirmed to be in full working order at the time of the installation) as well as the coolant. It's still running hot, and I'm at a loss as to what to replace next. My mechanic thinks it's a blown head gasket but when we tested the coolant for exhaust gasses, the test was inconclusive. I've noticed no power loss or any other signs of a blown head gasket or cracked head (no smoke, no coolant or traces of coolant in the oil or discolored plugs, etc.).

I shot the block with a laser temp gauge in a number of spots; between the headers I was getting like 210 degrees, but at the top by the plenum it was in the 140-170 range.

Any advice would be really appreciated as this has become a frustrating problem and I'm growing concerned to drive the car fewer than a few minutes.

drohalloran

To make matters worse, I just took the car out for about 30 minutes of rigorous driving and it never went past the 1/2 but when I shot the block with the temp gauge it was reading about 100 degrees Celsius

ritzblitz

I don't understand the last post, but there is a very helpful write up on Clark's Garage regarding cooling fan testing on early cars.

This sounds like some kind of electrical gremlin.

The cooling fans should NOT run until the switch on the radiator flicks them on. At least that's how I think it goes.

My cooling fans don't work at all (relay). And my car still won't go past 3/4 on the gauge, unless I'm sitting in traffic or it's a hot hot day.

Maybe there is another problem?

drohalloran

I'll have to check out the clarksgarage post, and what I meant in the previous post was that I drove the car and the gauge didn't go past the 1/2 mark, both fans were on and when I tested the temps it was still what I would think would be a little high

ritzblitz

Hmm, I can't really help you any further. Go to clarks garage and that will probably tell you something about your problem.

Otherwise, there are plenty of other people on this forum who might know what your issue is.

ArcticSteve

I'd remove the thermostat temporarily regardless if it's new.