98Boxster

My 944's water temp goes up quickly (within 90 seconds) to almost the red area when I'm standing still. The other week I got home - it got hot 5 blocks away(long light) - and after I turned it off, the car's overflow hose let loose about a good quart of coolant. On prior 944's I'd just put on the air conditioner(even if it doesn't work) and it would kick in the fan to cool the coolant. I checked, the one fan works, but to no avail. It only does this when I'm standing still or riding REALLY slowly. Any ideas why my air conditioner isn't lowering them temperature like it used to in my old 944 and 968? This one is a 1985.5.

Thanks.

PeteL

Try bleeding the coolant system again...and again. Takes alot to get the air out. Also, have the front of the car elevated and heater on full when you bleed the coolant.

924RACR

I'd be concerned about the coolant system, actually, not the fans; most likely a blocked radiator (feel for a cold spot), or perhaps some other failure in the liquid system, like bad t-stat or water pump dying... maybe a blocked or collapsing hose? The temp shouldn't pop up that high that quickly, unless maybe you've just done a 80mph run and parked it at the bottom of a freeway ramp.

If the rad is partially obstructed (cold spot), that would also explain why the fans can't help it.

Both fans should be activated by the AC switch; check for either a bad fan motor or some electrical problem - starting with the relays, from my experience (though I did also have a fan die on me). See if the fans spin easily by hand, and if they turn at the same speed (one of mine was quite slow).

98Boxster

Thanks for the quick replys! So BOTH fans should run with the air on and not just one? Yes the car runs at normal temp, until you come to a stop. Doesn't matter if I came off the freeway or regular roads or if it's hot out or cold out. My old 944 and 968 did the same thing(they didn't like stopping or very slow driving), just not as quickly and those ones' fans would come on automatically to lower the temp. I'm not to mechanical, sounds like I'll have to take her in I'm afraid.

quinnfiske

I would second the vote for bleeding the system. The bleed port is not the highest point in the system, so it is inevitable that there is an air bubble. I bled mine about 10 times before I got all the air out. It helps to run the engine up a bit when you open the port.

Robert D

Actually, with my 944 the high speed fan would not kick on when the fan switch started to go bad. Check the fan switch (screws into the radiator) and also check the relay. When the high speed fan was not working, the temp did kick up very quickly at a stop light...texas heat did it for me. If you have another 944 or know someone local with one; ask to swap out the relays to diagnose if yours is faulty/working. FYI I believe the fan switch is still relatively cheap by P-car parts standards. It takes a pretty large socket if I remember correctly.

MichelleJD

You can check to see if both fans are working by turning on the A/C - that will automatically kick in the second fan. If it doesn't , you,ve found the culprit. Otherwise, I second (or third ) the motion for bleeding.

Dal Heger

On a 85.5+ car both fans come on. No other options, they are either both on or off, low speed or high.
Check the fuse box for both fan motors, there is one fuse per fan if I remember correctly. Check the thermoswitch on the radiator, if it fails the fans will not turn on and you will overheat when you are moving slowly or stopped. Check the big silver relay in the back of the fuse panel, that's the fan relay, they have been known to go bad. It's about $120 to replace, but I think that is what it may be, based on your description. If only one fan turns on, check the fuses first, then the relay. It would also make sense to make sure that the connections are good on the fans themselves, they shouldn't work loose, but who knows?

Good luck.

Dal.

Robert D

Hmm. I thought without A/C one of the fans (passenger side) was usually off...if not possibly both of the 944s were working incorrectly when drove them.

meek

Sounds like it is more than the fans not working correctly. Had the same issue in my Turbo and turned out to be a seized thermosat; wasn't opening once the engine had warmed up and was allowing the engine to cook. Chaned the water pump while I was at it.

Rich Sandor

When you bleed your coolant, MAKE SURE YOUR FANS ARE ON HOT AND TURNED UP ALL THE WAY.

This will ensure complete flushing out of any air in the system.

I've had this problem MANY times (on different cars) and a proper bleeding always fixed it.

Rich Sandor

BTW, a good way to test this: If the temp rises quickly at idle, try blipping the throttle above 1000 rpm. The temp should drop straightaway.

If it does, it's a coolant bleed problem.

If it doesn't, it is more serious, like a fan or thermostat or blockage problem.