roman944

so since I've gotten the car, I noticed that it liked to overheat, so I checked/added antifreeze (50/50 premixed) and it has gotten better, but it still overheats

when I turn the "air" on, the car stays at 3/4

the hood and the block itself don't seem to be overheating

I don't have a milkshake, although the car IS due for an oil change

and the car has no leaks

so today the weather is so nice, so I took the roof off, and went to see a few stops for a possible BBQ, and saw the car started overheating slightly again, then the temp gauge moved ALL the way to the right ( way past the danger zone), so I turned "air" on and it went back down to 3/4 and stayed there; with the temp gauge being in danger zone, once I get on the freeway, it drops back to 3/4 and stays there untill I get off the freeway - then it goes back to the "hot" zone

so just now, after driving like this for about 1 hour, I came home, poped the hood - and started checking fans (I'm not sure if I can hear them or what they are supposed to sound like); but I figured - since the car cools down once on a freeway, then there must be something wrong with fans?

here's what I found:
I have 2 fans, 6 fins on each; each fan has a plug going to it; 1 is plugged in, and the other one isn't - the connector is just hanging on the bottom (below radiator); so once the car cools down, I am going to go back outside, and see if I can plug the fan back in, and drive around for half-hour or so and see if my overheating issue becomes better. I still think I need the system bled, and add coolant, but I am begining to think that this could be the culprit!

also, yesterday the after car overheated, I stopped at a store, I went out of the car, and heard a humming noise - waterpump working, so that can't be the problem. I also heard (and once I poped the hood) boiling sound and "bubbles" in the coolant tank - which I know is not very good, but not much I can/could do.

now, my question is, there are 2 plugs - 1 for each fan - is that the same on "your's" car's? and does one fan control the other? like, there is one "main" plug, and the plug to the 2nd fan goes from it. so if that plug is not plugged in, then both fans are off?

just wondering and hope I can get this solved without major headaches

the car runs great, no hesitations, no nothing, really great, even with "overheating" thing; but I am still a little worried

shiners780

Roman, yes there are separate plugs for the fans. Sounds like one of yours might be disconnected.

My offer still stands, if you want to come over I can show you how to bleed the cooling system. I will be around this weekend, just give me a call first. I wouldn't be driving around with the temp gauge going into the red zone. Excessive heat can cause bad things man...bad things.

jtsporsche

i can deffinatley hear my fans running after i cut the car off (and its still warm). only one fan spins but its very noticeable.

roman944

it's been doing that since I got it, in a way
I'll give you a call now!

thx Jim

PS: I thought you had gone to the track this weekend, the NYIRP (or w/e its spelled, a few people from up here went, but I had something else planned)

V2Rocket

the humming noise you heard was probably the sound of the fluid boiling, i heard a similar sound when my old mazda overheated.

plug in the fans and check your thermoswitch.

Campeck

is it a turbo?

when the turbo water pump runs you will hear bubbling and such from the coolant tank. (i think...)

shiners780

The low speed fan kept running after the car was shut down, and wouldn't shut off without pulling the plug off the fan or pulling the relay out.
Not a turbo, 1984.

We pulled the fan relay, the part number didn't match my reference book. When I put it back in the high speed fan went on with the key in the run position, off when the key is in the off position, but the low speed fan still ran and wouldn't shut off.

I advised Roman to order the proper relay, as the part number didn't match ( nor did some of the other relays ). The thermoswitch might be a good idea too.

So basically: low speed fan runs continuously even with car off, high speed went on intermittently. We bled the cooling system, there was a bunch of air. Put in close to 1 gallon of water. Cooling system holds pressure except for the cap on the reservoir (reservoir itself real close to giving up the ghost too). Pulled plugs and no coolant sitting in cyclinders, plugs looked good.

Any other suggestions for Roman?

roman944

hey Jim, I just came home, parked, walked to open the door - and saw green stuff on the ground. checked under hood, and its from under the cap

lol

shiners780

If you want to get a cap fast, these guys http://www.thebrakestore.com/ can get one in the next day. I bought one there when I was in a pinch and couldn't wait for shipping. They are located downtown just off the inner loop.

As far as the fan problem, I think the thermoswitch may be the culprit as someone else mentioned above. See http://clarks-garage.com/shop-manual...m#earlywithair

That's an easy repair, and not a real expensive part http://www.paragon-products.com/prod...3.959.481d.htm

If you change it out at the same time as the expansion tank, you will only need to bleed the cooling system once.

roman944

yeah thats what I think I will do; thanks for the links!
also, the car was left parked since yesterday around 4pm, and I got back to drive it today around noon, and it ran fine, no overheat yet

this is the weirdest and the most exciting car I have EVER had!

FRporscheman

Note that the early temp gauges are prone to not work accurately! Well at least my '84 temp gauge likes to hop around. I smack the dash and it hops around some more.

Use water wetter or a similar product for lower temps, properly bleed the system, and make sure the fans work, and you should be good to roll!

roman944

yeah I just need to find new fan sensor, or maybe someone has a good used one? I'm not entirely sure where to look so I get the right one; then with fans on it should get much better untill the tank and new cap come in

J Silverman

The fan switch is cheap. $12 or so from any of the online parts vendors. I like paragon products.

One thing to check, if it hasnt been done already, my 924S would have a similar issue with the high speed fan coming on with the key in the run position. Turns out the fuse for one of the fans blew, and I guess that opens the circuit causing the other fan to run on high constantly.

xsboost90

w/ the car off and cooled- put your hand on the fan blades and spin them- if there is alot of resistance or it doest spin free the motor is toast. If they are ok, plug the fan back in and let it sit and idle until the temp comes up. Then the fan should kick on at the mid temp on the gauge. If the temp gets higher than the middle EVER and the fan doesnt kick on you prob. need a temp sensor or you have fuse/relay/wiring issues. I run mine hard at the track all day long and it never goes above the mid line except when i pull into the pits then it rises slightly, then drops when the fans kick on.

roman944

well I kinda already know that the fan was unplugged - me and Jim are thinking that the problem is most likely is with the relay

when fan is plugged in, its on all the time, most likely because the relay is wrong; also, when we took the relay out and plugged it back in (we might have plugged in the wrong relay) which might have caused highspeed fan to kick in, or the relay inside is really bad, and something made highspeed fan turn on instead of low speed. as of right now, the fan will simply stay on all the time.

I think that the antifreeze that leaked out was the "excess" ammount (we probably overfilled it a little); I think the best way might be to try a new cap

can someone show me which fan relay I am going to need (link online) - this is for the early, 1983 944? I was thinking of changing the thermoswitch, but IMO, untill I atleast can get myhands on a good relay and see if my fan will stay off when I turn the car off, it might be not worth the trouble

the tank is also dirty, hard to see the "level", so that needs to be done either way at this point