..ok since i got my car in may is has run hot and ive slowly repaired things to cool it down...

1984 Pontiac Trans Am
L-69 High Output 4bbl 5.0L
T-5 5spd transmission
3.73 open rear
single electric fan

The Airdam is intacted...

Things ive fixed...in no special order..

-hypertech fan switch on at 177* off at 166*
-sending unit for gauge
-2 computer sending units on the gooseneck. (where the thermostat goes)
-new 160* stat
-secondary 14"pusher fan on the front of the radiator.
-the radiator was removed cleaned and pressure tested..
-system flushed and new antifreeze
-new rad and heater hoses
-new 16 lb rad cap
-checked the timing...2 degrees advanced
-the water pump works..(ran car with the cap off saw water moving around..and it does not leak from the little hole..)

ive come to the conclusion that the gauge was off at one point...it was reading in the red when my car was at 180....so i have a digital thermometer in the radiatior..

...i drove my car 40 miles to a meet and 40 miles back...when i pulled in my driveway the car was totally overheated.....all highway

..i never turned on the A/C...i had the heat on and i kept taking the car out of gear to help cool..i drove it easy...

i noticed a small leak from a heater hose...where it connets to the heater core...so i bypassed it...just linked those hosed together with some hose clamps and a coupling..

..i took my car out and instantly the gauge was in the red....fans on..no air...so i got out and checked with the digial thermometer...the car read 150....

ok so i went for a drive for about 20 minutes...some highway...some city..and easy drive...and when i got home the car was boiling over..

im pretty sure the rad has been changed because there is a low coolant sending unit on it and i dont have provisions for it in the consol.....

the air temp today was around 90 and the temp tonight was 80..


..im about to purchase an aluminum radiatior so i can actually use my a/c for once..and im gonna take the gauge to the delco remu electronics place (dealerships send there radios here to be repaired....the place said they can check it for me)....if that dosent fix my problem..i dont know what im going to do...

please help!!
thanks

 

You have a new cap, but maybe the system still isn't sealed. You might want to check for pressure leaks or a blown head gasket.

 

i did a pressure test...it was leaking from the hose going to the heater core... once i bypassed it the car held a 16lb pressure for 10 minutes...