924Board.org

gautney · Posted: Tue Oct 11, 2005 9:12 am Post subject: Overheating 924

I am new to this board. I have a 79 924, and it will not stay cool. I have replaced everything I can think of, new coolant, thermostat, fan switch, and there is no water in the oil, it has no leaks. If anyone can help I would greatly apprieciate it.

Thanks!
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1998 Boxster
1979 924
1962 356b

numbbers · Posted: Tue Oct 11, 2005 9:43 am Post subject:

Is it a 924 NA, or a 931?
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1980 924 Turbo

gautney · Posted: Tue Oct 11, 2005 9:57 am Post subject:

924 NA
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1998 Boxster
1979 924
1962 356b

numbbers · Posted: Tue Oct 11, 2005 10:04 am Post subject:

OK, you are in the wrong category. You need to move this to the general discussions category. You will get a lot more responses. My experience with the 931 is that most overheating problems are caused by vacuum leaks. But, you also may have a stuck thermostat or bad waterpump.
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1980 924 Turbo

924 turbo · Posted: Tue Oct 11, 2005 2:42 pm Post subject:

Does it overheat when you drive around or when you're sitting idling? Or both?
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Jon Furst

leadfoot · Posted: Tue Oct 11, 2005 5:21 pm Post subject:

First you need to make sure that you have bled all the air out of the system as the air gets trapped around the thermostat and it won't open the way it is designed to.
When you bleed the system have the heater gauge on full hot so that air does not get trapped in there.

There are different thermostat temperature ranges that you can use, so make sure yours is in the right range.

Feel the pipes going to and from the radiator, if one is hot and the other cold then you have a flow problem, either related to the thermostat not opening or there being a blockage in the system somewhere.

Look for leaks, especially around the back of the head, I have had an instance where the thermo time switch was degrading and the plastic cracked and leaked coolant out allowing air into the system.
Leadfoot
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1981 ROW 924 Turbo -
carbon fiber GT mish mash
LS1 conversion in progress...

gohim · Joined: 02 Nov 2002 Posts: 4459 Location: Rialto, CA

Where does the pointer on the temperature gauge point to, and at what point do the cooling fans on the radiator turn on?

Oops, the cooling fans do turn on right?

Do you have one of two fans?

Tigger937 · Posted: Wed Oct 12, 2005 1:08 am Post subject:

Make sure the fans are spinning in the right direction.
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1981 931 (Concours)
1982 931 (Daily Driver)

"Think outside the box"

gautney · Posted: Wed Oct 12, 2005 1:27 am Post subject:

I checked the system for blockage, have bleeded, replaced thermostat, fan comes on between 1/4 and 1/2 mark, seems to get hot when it is idle. Thanks for the advice!
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1998 Boxster
1979 924
1962 356b

timstar92404 · Joined: 22 Sep 2004 Posts: 2075 Location: richmond BC

you have to check the thermostat, if there are no leaks (water pump).

also check if the water pump turns smoothly and is not grinding.

the most likely thing that causes quick overheating is probably the fan not coming on. you have to check that it comes on and says running, it could have bad wiring and come on and then shut off . that way myproblem.

other thing I can think of is if there is a ton of crap (sand, rust etc) in the cooling system, there was a ton in mine I had to flush it several times with water and hose it out but that still didn't get everything out.
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78 924 sold.
85.5 944

Tigger937 · Posted: Wed Oct 12, 2005 2:20 pm Post subject:

helowrench · Joined: 25 Nov 2004 Posts: 44 Location: Dallas

get it running and idling.
after the fan(s) come on open your hood.
does this cause the temp to go down?

post back

Rob

gautney · Posted: Thu Oct 13, 2005 5:58 am Post subject:

It is the same with the hood up or down.
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1998 Boxster
1979 924
1962 356b

numbbers · Posted: Thu Oct 13, 2005 7:35 am Post subject:

Not to get too basic, but is your alternator belt good and tight? The same belt runs the waterpump.

Is the car actually boiling over? Or just getting up high on the guage?

Are you building pressure in the overflow/fill bottle?
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1980 924 Turbo

gautney · Posted: Thu Oct 13, 2005 8:06 am Post subject:

The belt has a 1/2 inch of play.
_________________
1998 Boxster
1979 924
1962 356b