Author Topic: 1976 Trans am 455 Pontiac motor manual trans  (Read 1599 times)

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Offline rbolte10

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1976 Trans am 455 Pontiac motor manual trans
« on: August 07, 2020, 10:29:35 AM »
I am have a over heating issue.  it is getting way to hot for my liking.  just seeing what other aftermarket cooling systems or any suggestions that are out there.  i already changed my thermostat 2 times and yes the fan is running the clutch is ok.  Thank you all for any help you can give!

Offline Aus78Formula

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Re: 1976 Trans am 455 Pontiac motor manual trans
« Reply #1 on: August 07, 2020, 10:31:46 AM »
Do you have the factory fan shroud?

Offline rbolte10

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Re: 1976 Trans am 455 Pontiac motor manual trans
« Reply #2 on: August 07, 2020, 10:49:56 AM »
Yes i do!

Offline Aus78Formula

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Re: 1976 Trans am 455 Pontiac motor manual trans
« Reply #3 on: August 07, 2020, 10:23:20 PM »
What model is it, TA or other? Do you have the plastic baffle strip under the radiator support that also directs air from under car, or front air dam?
What radiator is in it, do you know the age or condition of it?
Coolant sensors are cheap, easy to swap it it to confirm same reading and to use a infra-red temp gun to confirm if gauge reading is fairly accurate too.
Do you know the age or type of water pump?
« Last Edit: August 07, 2020, 10:27:38 PM by Aus78Formula »

Offline rbolte10

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Re: 1976 Trans am 455 Pontiac motor manual trans
« Reply #4 on: August 10, 2020, 09:17:21 AM »
Its a 455 4 speed, Pontiac motor, i do have the plastic baffle underneath to direct more air.  I am not sure what kind of radiator i did have some work done to it about 6 to 8 years ago it does look aftermarket and at that time the water pump was changed too.  I live it PA so it does great really humid here.  i rode into work today it was 66 degrees on way it and only crested 200 one time (as long as i was moving).  At a light i got to about 210 but then light changed.  Thank you for your help!

Offline Aus78Formula

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Re: 1976 Trans am 455 Pontiac motor manual trans
« Reply #5 on: August 11, 2020, 12:02:00 AM »
All good ,just going over basics that are easy to check or put down as an unknown for later. Apart from getting hotter when not moving, does it actually start to overheat, spit coolant or run rough? And the fan clutch seems to be working, you can hear it locked up when engine seems to be hot? Another easy way to test is to turn off the engine when hot and see if fan continues to spin freely or also stops with pulley. Or maybe it's just a big engine running warmer when at a stand.

Offline Jefe

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Re: 1976 Trans am 455 Pontiac motor manual trans
« Reply #6 on: August 11, 2020, 10:37:49 AM »
I installed a Flowkooler (https://flowkoolerwaterpumps.com) water pump on a 403 I built for my bird. Haven't run the car yet, but they are supposed to create much better cooling. Also, try a water wetter product (https://www.redlineoil.com/waterwetter-coolant-additives) or go with water-less coolant (https://www.evanscoolant.com/)
All of these things can help with overheating, but, making sure they're not just band-aids placed on a problem, is essential.
Has the car always run hot? Did it just recently begin running hot? Any recent work or adjustments made on the engine? Is it really running hot or is it a malfunctioning gauge or sending unit? Running hot at idle and not while moving, sometimes indicates a fan issue (clutch) or even a restriction in the cooling system. Best to work through all things and then move on to the items I mentioned above. Keep us posted as you work through it.
Jeff-
Current project
1979 Firebird Formula / in the family since new
Previous projects
68 Chevelle
72 GTO
78 DKM Trans Am #127