# High temperature



## mdilello (Aug 1, 2007)

I have a 1970 GTO that has a built 428 from a 1969 Gran Prix. I just had the AC repaired in the car and changed over to 134A. Let me start with I have a good 4 row radiator, a new 16 lb radiator cap and the proper mix of coolant and water. With the AC off the car runs 180/190 when in traffic 200, with the AC on the car runs 200 and in traffic can go as high 225, but as soon as I get moving again it starts to go down. This is the first big block car I have owned, people keep telling me these are normal temps and not to worry. I would apreciate some feedback from someone who knows Pontiacs.

Also can someone tell me what a 1970 GTO with a rebuilt motor new trans and in excellant shape is worth. This is a true California Car that was brought to Florida in 2006.

Thank you for any help you may have for me


----------



## svede1212 (Nov 1, 2005)

134A runs hotter than good old R-12. the charge of the AC system would affect that too. an over charge is going to give you high head pressure and temperatures. the AC blows it's heat back into the radiator so it's possible what you are experiencing. you did not state what the ambient temp was. being Florida i'd guess it was warm out.


----------



## john23 (Mar 6, 2016)

cooling issues can be a can of worms, but i will keep this short...while there could be a number of issues here, and many cooling issues are a conglomerate of several problems...the clue here is your statement... "but as soon as I get moving again it starts to go down." this indicates an airflow issue and not a water flow issue...therefore check your belt tension and fan clutch if your car has one....see that the fan is between 1/3 and 2/3 inside the shroud...that the shroud and other seals are present...that the radiator or air conditioning cooler isn't plugged with road debris....also, did you change pulleys? speeding up the fan with a smaller waterpump pulley or a larger balancer pulley will help air flow issues....something else to consider is this--because you are making more power now, your radiator has to work harder to lose the heat...add the increased load of the a/c and , in traffic, your cooling system isn't up to the task.......good luck with what can be a perplexing problem...


----------

