[kool_guy_70]

Hey guys so I bought a 99 cobra it has a built engine all forged internals low compression with a procharger, the previous owner told me that when the a/c is on it overheats,(he didnt lie) so anyways I picked it up in pheonix was about 100 degrees out was day time drove it hard in stop and go also on freeway drove to my town which is in az but high altitude about 7,500ft so its considerably cooler here, when I got here knowing I had made it home and wouldnt be stranded I turned on the ac no problems, about a week later going to work coolant came out I found a pin hole leak in the hose where another hose had rubbed through it, it was hard to get it to leak again though the hole was very small, I replaced the hose thinking that was the problem, well I went back to the heat this weekened and it was fine untill the a/c is turned on and you can bet it will heat up everytime, the car had an after market oil cooler added just cause that is about when this started happening said the previous owner, to try to cure it a ron davis all alluminum radiator was added, so what next? I replaced the radiator cap and he said the thermostat was replaced but I cant see it being the thermostat since it only overheats with the a/c on, is a/c overcharged? fan not working? I am confused here also I saw the oil cooler was mounted flat not upright so air does not flow thru it but is this enough for a/c to overheat it? like I said no matter how hot and how hard I drive it wont overheat but a/c kills it quick PLEASE HEPL! THANKS!

[guntek18]

Just trying to help.

you could have an over charged ac system. it should guage out at 40 p.s.i. on the "low side". maybe your compressor bearings are worn and producing a bigger load on your motor. by this i mean to say that your r.p.m 's may be lower than they should for your water pump to turn at a specific rate. also check for pump-belt slippage.....also maybe your thermostat is worn/defective and wont operate to specs. in the first place..........whatever it is, its under our noses so dont give up bro.

[01cobradude]

Does it heat up in stop and go traffic, on the highway, or both? If it is only in stop and go, I would suspect air flow problem. Does the fan turn on when you turn a/c on? Do you have a stock grille or aftermarket? Is airflow unrestricted through grille, condensor, and radiator? Does the engine have underdrive pulleys? Maybe the water pump is not turning fast enough. Look at radiator hoses when revving engine. A weak hose could suck shut at high rpms. I doubt an overcharged a/c would cause overheating. It sounds like something in cooling system is marginal and the a/c adds more heat to the system.

[kool_guy_70]

The its mainly stop and go I have grill delete but the stock bumpers dont allow much air... and with the intercooler in front of it I dont know,,, the fan comes on I think I may buy some aftermarket fans, but no on the underdrive pulleys and I was told the a/c has a safety if it is too overcharged it will bypass I have no idea though I guess Ill hook a guage to it, and the thermostat was the first thing to be replaced followed by the radiator cap...