Bryan Welch

Car: 1991 944S2 with 190,000 miles

Do your cooling fans typically run for a while after you park your car? It's around 50 F degrees outside in Iowa, and my temperature gauge says the engine is at around 95 C (below top white mark) when I park it after driving home. Working with a mechanic, I'm told the cooling system is fine and the gauge is just reading high. Thermostat, sensor, radiator, and hoses have all been replaced recently with no effect. The cluster was taken out twice to clean grounds, too. Oh, using a laser thermometer near the sensor agrees with the gauge, 95 C when fully warmed up.

It bothers me that the gauge reads about a needle width below the top white mark any time the car has been warmed up. All I can think to do is change the thermostat again to open at lower temperatures.

Ideas?

thanks,
Bryan

Kevsporsche944

Mine run after you park. My temperture gauge will get close to the top mark but never goes past that. I have never had a overheating problem. When I do my timing belt change I will get a lower temp thermostat and low tem fan switch.

This is all normal and all is okay.

hockeydude

low fans will shut off when you turn off the engine, yet the high fan will run until the engine temp goes down.

WizPorsche944

The longest mine ran after stopping the engine was like 3 minutes.

hockeydude

yea, i'd say that if they are still running after 7 or 8 minutes then the relay or temp sensor is bad. (pull the relay to prevent draining of the battery)

RedRose

Shouldn't run too long, but mine run even in the winters here :P And we both know I don't even need fans during the winters here, no matter how hard I run the car

Bri Bro

That white mark is 100C so your car is running at the temperature of the thermostat which is more then likely a 95C part. It running normal.

PeteL

Yes. It is fine. My car (86 944) the temp gauge hovers near the lower mark all the time.

M758

Yes,
Sometimes they won't run, but often they do. I even have turnd the the car off with no fans then had them turn on. If they run for too long you have an issue however.

944Ross

My early car only runs one fan, and it seems like at slow speed, when turned off. I've never heard both or high speed. Are early/late different in this respect? I thought late had two big resistors (one for each fan) to run them slow after shutdown?

p_tothe_g

I overhauled the cooling system on my S2 a few months back, waterpump leak and only had one fan running. The logic of the electrical diagram (focus on fan relay, fan switch in the radiator, ignition switch), they should run at proper temp after ignition is shut off.

If it is a cold enough day/night mine won't come on.

If running the car hard on a cool night and then stopping suddenly and shutting it off, they won't be on immediately, but after a half minute or so when the radiator soaks a bit of heat, it triggers the fan switch in the radiator, turning the fans on until the radiator core temp drops below the threshold for shutting off (which is a lower temp than needed to turn it on).

And if running hard on a hot day, there is a 100% chance it will run after the ignition is shut off.

Sounds like yours is running fine, maybe a touch on the hot side, but fans sound like they are running correct.

smokin_944

944Ross, it looks like your cooling system is working fine. The early cars run one fan in slow mode after the engine is shut off until the temperature of the coolant reaches a predetermined point which triggers the thermal switch to the open position thereby shutting off the fan. The later cars have a different system than that. Early cars have a single resistor for the slow mode because only one fan runs slow on the early car at low temp. When high temp is reached, both fans run at high speed. If you turn the A/C on, both fans run at high speed. Read Clark's Garage to get all the info you'll ever need about the cooling system.

CPR

It means you car is self destructing. Part out at once.


J/K....very much the norm. Mine will run for upto 4-5 minutes in the summer. Perhaps a 1-2 min in the winter.

It is when things are quiet........