Hello. I have a 1995 GMC safari van that is overheating badly. It was doing fine until i replaced te ac system. It would run fine, but if i turn it on it will overheat. I replaced all of the ac compenents. Everything is new. I also replaced the water pump, the fan clutch, the belt, new antifreeze, a new thermostat, and i even flushed out the whole thing. i thought it might be the guage, but the water is boiling when it gets hot. Everyone at the local advance auto, and anybody who overheard was stumped. i am stumped. i am getting water circulation. Could it be an engine problem. the engine runs great, no knocks or smoking.

Also the ac system is working fine, its blowing cold. (Just thought id let you know, cause everyone kept asking me that)


It looks exactly like the van in this site, except for the wheels. also mine doesnt have the roof rack, or funning boards. But mine is a safari SLE RWD.

GMC Van Pics

PLZ help Thanx in advance

It is a head scratcher isn't it? You can drive it all you want,anywhere you want without the a/c on and it's works perfectly right?
The a/c does put extra stress on the engine. Do you think the radiator could be plugged to the point where under a normal load it doesn't bother without it on,but affects it when being used? Other then a pinhole internal leak(nothing on ground?),that's the only thing I can think of. I take it the air didn't work before you replaced it,so you didn't have this problem before? I know you said you flushed it,but.......

One thing that I thought of, is there a cooling fan that's supposed to go on when the AC starts, it' would be located between the engine and the radiator, it should provide extra cooling to the radiator when the compressor is running. It should have a sensor plugged into the radiator telling it when to go on.

Maybe this fan is not working and when the compressor is running it's just too much load for the cooling system

Thnx 4 the resonses. No, nothing is leaking. the radiator has 3 areas, 1 for the coolant, 1 for the oil, ad 1 for the transmission fluid. The oil and the transmisson parts in the radiator were completely clogged up. im cleaning it up now and ill see what happens. also it only has one fan. It is connected to the water pump attached to the fan clutch.

Just to be clear, its like having a radiator, a transmission radiator, and an oil radiator all in one.

Thanx agian

Yep, gotcha. Actually they're called coolers. Very familiar with them on my machines at work. A lot of cars have trans fluid coolers,some have the other or both. Anything with a factory installed trailer package have them.

yey. The radiator was the problem. Finally the @#mn thing works. Thanx 4 all da help.

D*#N!!!!!!!It works better, but i went out one day for about a 20 min ride with the ac on and the temp guage went all the way to the red area. the middle of the guage is 210 degrees, and the end of the guage is 260 degrees. it was at about 250. I am stumped at what the problem could be. it will go for a longer distance since i cleaned out the radiator, but still gets too hot. I just went to florida in a rental van and the temp didnt go past the half way mark, and i had the ac on the entire 340 miles. people keep saying its a blown head gasket, but it doesnt smoke, it has lots of power, and it has good response.

PLZ HELP

If cleaning the radiator made a difference, it is time for a new or rebuilt radiator. At 250-260 deg you are flirting with engine destruction. Which is less expensive??

It actually didnt make a difference. I thought it was runnin bettter but i was wrong. Yesterday i replaced all of the spark plugs. They were blistered white probably due to the overheating. also the electrodes were worn down a bit. also we found that the transmission fluid was completely full of dirt and debris. we replaced the fluid and the trans filter. Today it overheated and went close to 260. Im running out of options. Could this be an engine problem. plz help

What engine?? It is beginning to sound like an engine problem, cracked head, blown head gasket..??