jderimig

So last year I resuscitated my '84 that hadn't been driven in a while. Belts, seals, new waterpump, injectors cleaned, etc the works.

Noticed that the fan switch doesn't come on until well after the 3rd bar and turns off just below the 3rd bar (5 years ago when I remember driving the car it would cycle between the 2nd and 3rd).

Checked coolant temp at the bleed valve with thermocouple and it seems on the hot side so gauge seems to be right and idle oil pressure when the fan kicks is a little low (~2 bars).

I know someone is going to ask which thermostat I got, I don't know, I bought the parts about 4 years ago from Pelican and I asked just to set me up (I assume they sent the standard, 80C?).

i think air is bled but I can check again. So should I just go ahead and change the fan switch?

--john
'84 NA since '83

V2Rocket

id go for the lower-temp fan switch, made a big difference in my cars running temp out here in the desert.

jderimig

Well changed it this morning. I had the standard 92C.

Same as before. Thermostat opens about 2 and 1/3. Fan starts about 3.5 (red is 4) and shuts off at around 2.75 on the gauge. So the ratios are about right. Going to chalk it up to a little temp sender drift and drive it.

V2Rocket

with the low temp switch my fan comes on between the first and second hash marks...it is comical how fast the temp drops with the giant fan

jderimig

That would be a problem with my setup, my thermostat doesn't open until after 2.

odonnell

I've heard that you really don't need to worry unless your temp is pretty much in the red (or yellow on early cars), 944s run hot. I have a pretty new thermostat, fan switch, and fan assembly and I'm usually bouncing between the middle notch and the one after it. During the heat of the day it's actually lower, I guess the ambient air temperature effects thermostat behaviour.

jderimig

Yes as long as I am moving the temp gauge reads what you are seeing, middle or slightly above. Only in traffic or idling stopped is when it climbs over the 3rd hash.

odonnell

Interesting. You're sure the thermostat is good? I would advise also burping any possible air bubbles out of your coolant. If a bubble builds up behind the thermostat, it won't open at the right temperature.

mytrplseven

When you "burp" the system, make sure the heater is switched on so you'll eliminate all the air.

jderimig

Thermostat: Well I am not sure of anything but it is repeatable.

The coordination between the fan switch and thermostat seems right. That is fan come on well after tstat opens and shuts off just above where the tstat opens (to keep tstat open).

I burped as instructed, tomorrow I drive it and bump it around to shake any bubbles to the top and burp again.