I have a 1975 Pontiac 350. I have replaced the water pump, fan clutch, thermostat, radiator redone, new hoses, new heater core, flushed the block multiple times, new radiator cap, new overflow bottle and that's all I can think of. The engine goes up to 220 sometimes higher. I have ran out if ideas what it might be. If anybody could help me I would really appreciate it. Thanks.
Still having Overheating problem NEED HELP PLEASE!
- Thread starter Btc89
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92 Sunbird LE
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Engine Friction ( worn mains) or Head Gaskets leaking or Radiator clogged inside or out?
This is the same Lemans in an earlier post?
Have you thought about getting an Aluminum radiator?
Had A 77 Bonneville with a 403, ran cooler in AZ with a nice Aluminum radiator,ran hot with stock radiator.
Did you try this? http://www.oreillyauto.com/site/c/d....oap?ck=Search_N0452_-1_-1&pt=N0452&ppt=C0180
Doug in P.R.
This is the same Lemans in an earlier post?
Have you thought about getting an Aluminum radiator?
Had A 77 Bonneville with a 403, ran cooler in AZ with a nice Aluminum radiator,ran hot with stock radiator.
Did you try this? http://www.oreillyauto.com/site/c/d....oap?ck=Search_N0452_-1_-1&pt=N0452&ppt=C0180
Doug in P.R.
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are you sure the gauge is accurate? can you rent an IR gun to verify the temperature? what is your initial timing set for? is it reaching 220 at highway speed or lower speeds/idling? are you using a thermostatic fan clutch? what fan are you using, factory, aftermarket, how many blades? are you using the correct radiator cap for a closed cooling system and how many psi? have you done a coolant hydrocarbon test for a blown head gasket?
I thought about going to a aluminum radiator. It gets hot just at idle in the driveway. The radiator cap is 21-25 psi, I have used the gun and its correct on it being hot, the guage is new so it works fine. I haven't done a blown head gasket test. If it was blown would I lose antifreeze? What kind of aluminum radiator did you get?
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why are you running a cap with that high a PSI? You are supposed to run 16 PSI you may have blown a head gasket. do you have white exhaust smoke when you start the car or at other times? You have not answered at what speeds it runs hot? what fan and clutch are you using?
92 Sunbird LE
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If you do figure it out and still need a radiator, this is the best price I found so far for a direct fit 2 core all aluminum : ( standard and automatic)
http://www.pwrradiators.com/1970-pontiac-lemans-tempest-gto-radiators/
Be Cool and others are alot more money.....Jegs and Summit and Speedway.
Stay away from plastic tank/aluminum radiators....
Doug in P.R.
http://www.pwrradiators.com/1970-pontiac-lemans-tempest-gto-radiators/
Be Cool and others are alot more money.....Jegs and Summit and Speedway.
Stay away from plastic tank/aluminum radiators....
Doug in P.R.
92 Sunbird LE
Well-known member
Yes, out the tailpipe ( white smoke- alot ) and the overflow will overflow coolant.
Doug in P.R.
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Icefan71
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Before you spend any more $$, can you tell us more about the engine? What heads, what cam? Whats been done to it? Where is your timing set at?
And questions from your other post on this problem;
Do you have the fan shroud in place?
Did you check the water pump divider plate clearance?
And questions from your other post on this problem;
Do you have the fan shroud in place?
Did you check the water pump divider plate clearance?
No smoke at all at the tail pipe, I wanted a 25 psi cap because that's what I wanted. Fan shroud is in place.I don't know very much about the engine. I know its a 75 Pontiac 350 I think with a mid grade cam. That's all I know. The timing is set at 16 degrees. I'm using q heavy duty fan clutch I bought from summit racing.
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when does it overheat at low speeds or highway speeds? did you check the water pump divider plate clearance? with the engine cold can you freely spin the fan or does it have a large amount of drag? what fan are you using, diameter and number of blades, it is a sold fan or flex?
When you changed out your water pump did you put the metal plate back in? It will overheat if that metal plate is left out. I purchased a 5 row radiator for mine. Pontiacs like to run hot. I hope this helps.
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