This has been a problem for the past 6 years my car will overhet when i have the ac on and am in traffic randomley sometimes it does it sometimes it dosent. Yesturday i had it on and it wa running at 180 but the day before i reached 260. When i have the AC off it will run 180 all day long. Also my AC is not blowing cold air its like luke warm i check the charge and it is full so i dont know why it is doing that. Here is a list of what i have replaced as far as cooling

Radiator
All my hoses
Water Pump
Heater core
Air Dam is there
I have flushed the system and put a 50/50 mix in with water wetter
Tstat is new
No coolant leaks
Basicly i have replaced every part that involves cooling my car. I have also made sure that the fins were free of debree in the ac condensor when i replaced my radiator.

 

do you have a secondary fan? is it working? I thought mine was working, but when I actually checked.. its not still trying to figure out why.

 

Check that your fan(s) are working. When you checked for debris in the condenser, did you check between the condenser and radiator? Lots of crud can get in there over time. Remove your upper radiator shroud/cover so you can see between the radiator and condenser, and while your in there, use a garden hose to wash out your radiator and condenser several times. Hose them out in both directions (forward and reverse).


How does the engine's temperature do on the highway at cruising speeds?

How is the AC performance on the highway at cruising speeds?

 

Fan works fine. I justhad my radiator out a few weeks back and there was nothing between it so that is clear sometimes at highway speeds it heats up sometimes it does not. I am at whitts end with this. I would say it is my underdrive pully but i had this same problem just as bad with the stock pully.

 

...hmm. do you have electric fans or clutch driven?

 

Electric

 

I'm not familiar with the v6 models...is it dual fan or single? I'm thinking that the secondary fan isn't kicking on - as the heat from the AC condensor and compressor aren't being cooled properly.

 

Its a single fan.

Oh yah i have also repalced the fan motor as well.

 

I'll try and dig up a wiring schematic tomorrow at work for your car. Something isn't right if you've replaced all that and the fan is working properly.

Curious though - did the overheating and lack of cold air start around the same time and get worse at about the same rate?

 

Yes it has gotton worse at the same rate. But this car has done this since the day i purchased it.

Today wheni drove it in traffic it did not heat up past 180 im soo confused about this situation.

 

When my car was low on refrigerant, one of the tubes coming off the compressor got pretty warm.. so I am assuming the condensor must get warm as well... so if you're low on refrigerant, maybe your fan can't keep up to the extra heat generated?

 

I checked the referegant the other day and it was full. How ever i have noticed were you put the referegent in does not get to cold or drip water like other cars.

 

have you checked your A/C system with a set of guages? What are your pressures?

also...when you say it is full how have you measured that?

 

I put a guage on it because i thought it might be low it showed about 45PSI i think. And according to what i read it said that that ment it was full.

 

does your compressor cycle on and off? if so, how frequent? when you checked the pressure, was the car on, was the compressor running? When your compressor kicks on it can take that 45psi right down to like 30... and a system needs a minimum of 28psi to run.

if your compressor kicks on for like 5 seconds, then off for the same... over and over.. that means your system is low. When my car was low... the a/c hoses were not cold to the touch either, and didn't have any condensation on them. But now that I've topped it off, they are almost cold to the point where you can barely keep your hand on it, and its dripping with condensation.

 

See the other day it was going on and off on and off that was when i was running at about 180 and the car was in a cool grague. Now when i checked it i did not hear it cycle on and off but i did see the clutch moveing so i assumed the compressor was on.

 

too bad you don't live around here... my buddys dad has a set of guages that will show if the system is low or not.

Did you test the pressure with the compressor on?

 

Ya the compressor was on does it make a difference if it was MAX or Norm i had it on MAX and my car was running about 240 at the time.

Would lack of refredgerant cause my car to run hot?

 

That I'm not sure.. but I know if the system is low, the condensor will be alot more hot, which in turn will add more heat in front of yor rad, and since the fans are pulling that heat through the rad, I think it would affect your cooling system. This is just a theory, if it sounds illogical, i won't be hurt..LOL

 

where I work - a/c service is cheap. It couldn't hurt to have a pro take a look at the system - you'd at least know that you have it filled to the correct capacity and that it's pulling the right pressures. I think this is the key to it all really - we need to know that the a/c is doing its job properly and that its not just causing extra heat.

when I say cheap I mean the service is 45 bucks to evacuate, check for leaks, use some tracer dye, and refill with freon. We charge per pound on the freon, so most people's bills are under 100 bucks. Either do that or get some good guages and see what's really going on with the system.

 

I checked the AC today when it was cool and my guage said it was low on refridgerant so i added some and it was blowing cool air and i noticed condinseation on the part were you put the refridgerant in. I hope this solves my problem.

Would heat cause my origonal reading to show it was full when it really wasent?

 

as far as I know, the only true way to measure if your system is "full" or not is to take what you have in there out, weigh it, then put it back in and add until you have reached the "full" capacity.

You can theoretically keep adding those stupid cans of freon until your system is WAY overful. There is no full reading...just a certain amount that is the known amount to use on our cars. Measuring pressure, like I think you're doing, is affected by: weather, temperature, altitude, the condition of your A/C system, presence of any leaks, etc. etc. etc.

Just my 2 cents tho.

And to directly answer your question: heat makes things (in general) expand, and the lack of heat (cold) makes things contract. So yes - your pressure reading would be higher if the system was heated. Note that this would not affect how much it weighs - which is the way that auto repair shops measure freon.

 

professional guage sets have a guage with a red, yellow and blue zone... whenever the compressor kicks on, the pressure drops down if its too low. This is how a/c mechanics know if it has enough freeon in it. It is quite complicated. a simple pressure test says nothing, as you learned yourself. let us know if that solved the problem.

 

Actually I think that's normal for one of them to be warm, the other one should be cold however.

It's just plain and simple, it just sucks driving these cars in the heat, too much stress while sitting in traffic seeing the temp gauge slowly climbing saying "haha pathetic human, I am going to burn your car down to the ground and there's nothing you can do about it" and then you say "but hey, why can't you just keep my car cool" and then it says "because I am a money hungry ***** who likes to take money and precious time while you pay attention to me and devote all of your extra time towards me" and you say "well, what if I sell you" and it says "then ill just overheat on the next person who buys it" and you say "OK" and then it says "OK" and then there is a rapid exchange of "OKs" until it overheats and shuts off.

...... or maybe that was only my experience.

 

Don't forget guys that even if the system is full if the orfice tube gets clogged up the ac won't cool properly because of the restriction.