924Board.org

[924martinirossi]

Repalced the thermostat and waterpump. Car still overheats. Check what next? Will blow out the radiator.

Can anyone tell me the coolant flow direction in a 931.

The car is fast and still for sale.

Michael

[Rick MacLaren]

Is this still the 931?

[924martinirossi]

Yes it is. This one is the 80 that is for sale. I just drove it home (arrived here at 8:59. The car did not go past the mid red mark. I know that I need the expansion tank replaced. If you leave the top off of the expansion tank and start the car when it gets really hot water just boils out of the tank. If you leave the top on, the water gets so hot the tank deforms and springs leaks.

Michael

[Rick MacLaren]

lol

Those leaks are nasty. The tanks aren't expensive. I have a used one if you want.


[ This Message was edited by: Rick MacLaren on 2002-10-01 15:49 ]

[Lizard]

try flushing the coolant system

[gohim]

Sounds to me like a blown head gasket.

My 77 acted the same way when I bought it, and the head gasket was the problem.

[Lizard]

I was going to say rad or clogged coolant passage

[924martinirossi]

I removed all the hoses and flushed out all lines and radiator, still overheats. Later in the afternoon I started the car up again and let it get hot. I saw stam comming from the front of the radiator and took a peek. There were two fairly large wet spots on it. I had washed the car earlier and thought it was just the water evaporating off. Humm...must not be and the radiator is leaky. this makes three bad radiators that I have now. Can these radiators be repaired or do I have to buy a new one?

Michael

[Paul]

I agree with Gohim, you've probably got a bad head gasket. I suggest you pressure test your cooling system and do a compression check before doing anything else.

I had the same problem, I kept replacing the parts that were being damaged by the leaking head gasket.

[ This Message was edited by: Paul on 2002-10-03 08:41 ]

[wdb]

its been my experience that a bad head gasket and or cracked head will cause the car to overheat quickly , where as running lean and bad timming and vacuum leaks take awhile for the car to over heat . how long does it take ur car to boil .

[924martinirossi]

I would just bum if it was the head gasket. I replaced it last year. Before I replaced it I couldn't resist and started the car. Had a nice white plume of smoke out the rear.

Ok. I break down and do a compression test. Car ran fine last night on the freeway last night and only went up to the mid red.

Michael

[Paul]

Have you retorqued the head since last year?

[924martinirossi]

No I haven't. I beleive the radiator is at fault. The radiator steams and has wet spots on it. Also I found the fan does not run very fast. A replacement radiator and fan are in order.

Are the radiators rebuildable?

Michael

[Lizard]

to have a rad fixed you could probably get a replacement used rad shipped to you and it will be alot cheaper and work just as well

[924RACR]

I got one re-cored by a local radiator shop... it cost plenty, but they put a huge 4-row core in it explicitly for racing. A stock re-core shouldn't be bad...

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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype