when a/c is on car overheats

[cnogood]

I have a 89 rs 2.8 engine my air works, but when I drive for bout a 1/2 hr or more it overheats. And when I stop I hear anti freeze bubbling hot in the over flow. Anyone have a solution. My fan comes on. So dats not the problem. Could it be to much anti freeze

[Xenostalgia]

check the simple stuff, radiator working, themometer working, fans working etc.

Does it ONLY over heat when you have the A/C on and doesn't overheat any other time?

[Nate355RS]

my 92 does the same thing, about a half hour with the a/c on and the temp guage starts rising. turn the ac off and it goes back down to normal. i don't know if this is normal or not

[89IROC&RS]

using the AC should not cause it to overheat, i would remove and test your thermostat in a pot of boiling water and thermometer.

[instantkevin]

the A/C does work the engine more when it is on. the temp will rise a little more. but what temp is your car at when you say it is "overheating?"

if it really is overheating, only with the A/C on.... then have you checked to see if the fan turns on when the A/C is on? If not, then you could have a malfunctioning "Fan A/C pressure switch". it regulates when the fans turns on/off based off the A/C pressure. i don't know how the two are related nor why they make it work like this. nor do I know where the switch is located, but i have a hunch it's actually inside the compressor itself... hence there are 3-4 wires that connect to the compressor.

just a possiblity.This could be one of the few problems I would take to the dealership (hard to locate the cause). (that way if they don't find it the first time, you can complain and have free work done until it's fixed).

[cnogood]

But wut is causing the anti freeze to bubble and boil in the over flow

[92zcamaroperson]

too much water in the coolant. when it overheats it boils. Or your radiator cap isnt sealing properly. Or your engine is really friggin hot. Which like was said before...could be your thermostat....maybe some leaves in your front cooling ducts.

[Xenostalgia]

Car over heats w/ ac = you care doesn't think ac is a good idea, get one of those plug in fans

[Viper_Storm]

Originally Posted by 92zcamaroperson

too much water in the coolant.

lol, i thought water was the coolant?

[Viper_Storm]

Originally Posted by Xenostalgia

Car over heats w/ ac = you are gay

wow, greatest helpful words ever! where would we be with out a post whore like you... lol

[Xenostalgia]

=D thx

[Rally Sport]

Originally Posted by Xenostalgia

Car over heats w/ ac = you are gay

Lucky 89 isnt here to threaten you like he did me when I said something was gay, stopped THAT.

About the overheating, sounds like your thermostat. that's probably the problem.

[89IROC&RS]

xeno has gotten a smack on the wrist and is changing the post, doing it again probly wouldnt be that smart....

[stepho]

Originally Posted by Viper_Storm

lol, i thought water was the coolant?

OH OH OH something I know a little bit about. You can use water as coolent it is supposed to be distilled water though (when I got my new radiator it said the warrenty is void if you use something other than anti-freeze or distilled water). It is best to run anti-freeze though. Anti-freeze is better because it has a higher boiling point than water.

There are two ways to keep water from boiling, keep it under 100 degrees C or keep it pressurized. Since the water is being run through your extremely hot engine keeping it cool is out of the question. There for you have to keep it under pressure. If you radiator cap is faulty or not attached properly it will cause pressure to escape which means the water will vaporize.

[89IROC&RS]

water is a better conductor of heat though, thats why you run a 50/50 blend, water cools, antifreeze does just that, keeps it from freezing, but it does sound like the radiator cap isnt doing its job correctly. should be a cheap fix or diagnostic test.