Car Running Hot -- questions/help
 

Hi Everyone,

Here's the situation -- temps, when under power, are great, totally normal. When I stop at a light, by the end of the light, the temp gauge is up at the top of the white or in the red. As soon as I get going, it shoots right down. Last night, for example, I putted a few miles into town to see a movie...parked, saw the movie, came out, cool night, car runs fine the few miles home. Driving is ordinary 3-4K RPMs, nothing exciting, a few stop signs, and then when I get into the driveway to thread the car past a few obstacles (mower, etc...), by the time I have it parked in the garage, the temps are up into red and when I turn it off, the fans come on.

I know I should be expecting rising temps at idle, but it just seems a little too extreme to be normal operation.

Any ideas?

What year and model is the car?

Sorry, 1987 944 Turbo.

two thoughts:

1) are your fans kicking on? The fan should come on at low speed at about 3/4 of the way to the top of the normal range, and that will bring the temp right back down to about 1/4. If there is a fault in the fan control circuit - usually the thermoswitch - you will have a problem.

2) are you getting good circulation through the radiator? In my NA I was getting real hot even after replacing the thermostat and the thermoswitch, I ended up needing a new radiator. (I'd had the water pump replaced with a timing belt service soon after buying the car, so ruled that out.) No problems after that.

good luck,

nate

fans work on shutdown, not with engine running...
definately something electrical

do you have AC? if so , push the AC button , fan should come up
does that work?

check the relay in the fuse box, take it out , clean the contacts
then push it in , pull it out, repeat about 10 times(scuffs up the contacts in the fuse box and cleans em a bit that way)

fuses on in the fuse box, should have 2, are they both good ?

thermofan switch in the radiator... pita to get to , difficult to measure resistance on that one...

try this: when the car is running hot, at a stop light or whatever, rev the engine. rev it a few times and see what happens, do this without putting the car in motion. return and report. (believe it or not, i may have an answer for you, depending on what happens.)

I hate to break in on Tazio's thread but I am having the same issue (though it may end up being a different cause). I went out for a drive today and, for the first time, my temp guage went up almost to the white area while at a stop light. I live out a bit so I did not hit amy more lights on the ay home and the temp was about 1/4 of the way up. When I git home I popped the hood and let the car idle. The fans never did come on and the temp steadily increased. I shut it down before I hit the white area and as soon as I turned the ignition off, one of the fans came on. The passenger fan never did come on. After the car cooled, I pulled the connector to the fan that did not come on and jumped across it with 12 volts and the fan would run. Are both fans supposed to run at the same time or is there a second high temp switch that triggers the second fan? Why would the one that was running only come on after I shut down the motor? So confused!!

Thanks!

Actually, yes, the one thiing I forgot to mention is that if I give the gas pedal a nice kick up to 4K or something, the temp drops.

I'm having trouble hearing the fan in traffic....sometimes I think it goes on, and the temp dips a bit back down to the white line, but then it comes up again...

My suggestions are to


make sure you hve properly bled the cooling system via clarks (I use the mouth to reservior myself)


check your t-belt tension as the water pump may be slipping due to not enough belt pressure (there are no teeth just tension turning the water pump pulley)




Next (if that doesn't work)I would look at a radiator flush

"Actually, yes, the one thiing I forgot to mention is that if I give the gas pedal a nice kick up to 4K or something, the temp drops. "

your waterpump isn't working correctly, either due to improper belt tension, or a faulty pump..

at least, that's where my vote is.

something like this happened to vinman, turns out his thermostat was stuck OPEN

So there seem to be two schools of thought here:

1) Air in system/thermostat failing
2) Something in the water pump

Any more votes? Obviously, I'm hoping for #1. I think the PO changed the water pump 20K miles ago, so I'm hoping he didn't get a lemon or something.

air in system, hopefully. failed head gasket, possibly, which is where i was going with my question.

Well, will find out on Wed -- taking it in to be looked at -- and will let everyone know. I'm hoping for the easy fix.

It was the fan switch combined with a huge anount of air in the cooling system becuase a lot of the coolant had boiled off or something. Head gasket, thankfully, seems to not be the culprit.

Mine won't stay cool either. Outside temp is 90 at night and about 105 to 110 in the day headed toward 120 plus!. Without ac its just above the normal range on the guage, but no problems. Turn on the ac and I soon lose coolant. The fans run full time and I'm not deep in the turbo. Do I need to relocate the ac condensor? Any other desert dwellers have this problem or have solved it?

Diverdan

Ok, this is what the techs at the place I took it told me -- if it's getting into the red, even for a little bit, get it into the shop or else you risk a head gasket or a melty engine -- the guys said I had just "use dup one of my nine lives." i think the cooling systems on these cars are not to be messed with.

;) I would like to agree on that last comment, but I don't!

I think what you mean is, if you have not got confidence to work on the car, let someone else do it!
Which to be fair, is right, if you don't have the skills and time.

The temp guage on these things (mine is an S2) has been problems from the time I bought it. Socal has given me the conidence to have a go at various things on my own car.

I presume that you had a look on clarks to check how to bleed the thing properly. The S2 has a problem with air in the system and even the Porsche specialist did not bleed it correctly, meaning Mine overheated on the way home. I was mad, and bleed it myself, and boy did I put some water in it! (yes hot water, and proper fluids)

So everyone should know, the S2 has a bleed screw at the top front of the engine and its vital that you check this, and as someone said. pressure the system by blowing into the filler. Do it if you lay the car up for the winter.

Lastly, the S2 has an additional temp stop light that comes on on the dash which really lets you know when its getting serious. I'm not suggesting you drive by this instead of the temp guage but the guage can play up if the earth is not clean and flicker up and down before settling down.

My point here is that this is what this site is for, having a bash at doing things if you can. Use the knowledge given to you to try for your self?

Tell me if I'm being a bit harsh ??????????

I just meant that the cooling systems are not to be taken lightly -- if there's a problem, attend to it now rather than later. I couldn't care less where people get their work done or if they do it themselves.

Right, I'm with you on that.