runs hotter with ac

[pontiac3100]

got a 94 pontiac grand am gt v6.

today it was about 90*F out so i had my a/c on.
before when i had it on the gauge would never go any higher than 200*F.
but today she stayed around 180*F, then maybe about 45minutes she raises to 200*F.
then about another 45minutes later she goes past 220*F.
and i turned off the ac.

The fan was on.
the a/c stayed cool.
i have a 180*F t-stat in....

[85_305]

Well since engaging your AC makes your motor spin a bit quicker due to the ac compressor coming on, it makes sense for it to run a bit hotter. It's a fairly common thing

[PCGUY112887]

As long as the temp guage doesn't get into the red your fine. Many people seem to think these engines are overheating since it is common for them to get to 220, but as long as the fans turn on and the tstat opens it should all be fine, they are made to be that hot.

If it gets to 220 then keeps going and it makes it into the red area, then you have a problem.

[pontiac3100]

well i'll giver her a shot again...
thanks.

when i first got the car i was worried that this engine whould blow the H/G.
but as i learned on this site and another...the only reason these headgasket blows becuase they let the engine over heat.

[IsaacHayes]

And if you see coolant in the oil it's from a leaky Lower intake gasket not the headgasket. That can take out your bearings too or make you over heat.

I've got 200,000 on mine and no blown headgaskets. It's even gotten close to the red once when the engine fan relay went out and it was idling with the AC on.

When the AC is on the engine has to work harder to turn the compressor, so yes it will put more load on the engine. When you stop is when it will heat up because there is less air flow over things.

[85_305]

I've got 200,000 on mine and no blown headgaskets. It's even gotten close to the red once when the engine fan relay went out and it was idling with the AC on.

Heck.. my 153k mile '91 SE has seen, and maintained red-line on several occasions when that damn upper coolant return line finally went. Never had a problem w/ the gaskets

[geoffinbc]

The AC does not take much power to run at idle. The reason the engine gets so hot is because of the evap core in front of the rad. It needs to disipate heat generated by the cooling of the AC unit (think of the coils on the back of your fridge) and this heat disipation inhibits the radiators ability to disipate heat.

Basically you are trying to get rid of rad (engine) heat and AC heat all with the same air. So to compensate and help out the ECM commands the cooling fan on. In traffic it is normal to reach 220 (104.4*C) or so. This is really not that hot for an engine. But constant driving at a descent speed should result in normal temperatures.

In the summer time you can help your engine out but draining the coolant and using filtered water and a can of Red Line Water Weter. Royal Purple makes a similar product called Purple Ice. Both will increase the cooling effeciency of the radiator.

Enjoy your A/C Fancy pants. I only have Vents.

[pontiac3100]

lol!
thanks...
so the redline just fill with water only and the redline stuff.

your right! the other day i had my hood opened turned on the a/c and that condensor got hot!

what about a more powerful fan.
the fan i got one of the guys at my job was impressed.
i guess it turns out that thats the same fan used in the 94/95 impala ss.

[85_305]

The AC does not take much power to run at idle. The reason the engine gets so hot is because of the evap core in front of the rad. It needs to disipate heat generated by the cooling of the AC unit (think of the coils on the back of your fridge) and this heat disipation inhibits the radiators ability to disipate heat.

Basically you are trying to get rid of rad (engine) heat and AC heat all with the same air. So to compensate and help out the ECM commands the cooling fan on. In traffic it is normal to reach 220 (104.4*C) or so. This is really not that hot for an engine. But constant driving at a descent speed should result in normal temperatures.

In the summer time you can help your engine out but draining the coolant and using filtered water and a can of Red Line Water Weter. Royal Purple makes a similar product called Purple Ice. Both will increase the cooling effeciency of the radiator.

Enjoy your A/C Fancy pants. I only have Vents.

Well. Here's somebody that knows what they are talking about

[geoffinbc]

lol!
thanks...
so the redline just fill with water only and the redline stuff.

Read the can it will give you mixing directions on it. Or check out the website.

[pontiac3100]

i agreed....
but whould a aftermarket fan be better than a stock fan??

[geoffinbc]

Marginally I would not bother switching.

[pontiac3100]

ehh okay.