Overheat only when a/c is on

[moi1463]

I'm not sure what is causing this problem, but basically my car starts to overheat only when the a/c is on for about 5 mins or longer. I have checked for coolant leaks, cooler thermostat, checked all belts, and both fans are on at all times. Still I cannot figure out what is causing the overheating problem. It will over heat whether if I'm going 70 on the freeway or 30. I hope it's not the head gasket and I don't think it is because I don't see any signs of the coolant mixing with the oil. Any suggestions will help greatly, because I need to deal with this issue before my long summer trip. I really don't prefer to drive 1400 miles without a/c.

 

[crazyquik22023]

Try going with a lower temp thermostat. Which do you have in now a 195deg or a 180 deg? if you have the 180 I probably wouldn't go any lower unless you have link or something to change the ECU "learn mode" settings. If you have a 195 I wouldn't see any problem to switching to a 180. Also check to make sure you are not low on coolant.

 

[moi1463]

Try going with a lower temp thermostat. Which do you have in now a 195deg or a 180 deg? if you have the 180 I probably wouldn't go any lower unless you have link or something to change the ECU "learn mode" settings. If you have a 195 I wouldn't see any problem to switching to a 180. Also check to make sure you are not low on coolant.

I did switch to a lower temp already, I do also have link.

 

[crazyquik22023]

Sorry should have checked your profile. Well if the car only heats when the A/C is on that usually means you are low on coolant or your radiator needs to be flushed and replaced with new coolant.

 

[deek00]

was the install on therm done correctly? i would just try pulling the therm out and making sure nothing is clogged in there and go from there. if the fans are coming on it shouldnt be the therm though (less you have a switch) and is it possible you would have air in your lines? it sounds like everything is working correctly though just not cooling it off

 

[moi1463]

Yea I checked to see if the stat is installed correctly and I flushed it out with new coolant. Normal driving everything is at normal temp ranges, but when I have the A/c on, it overheats. I have no clue why.

 

[tonyseagle]

Just a wild guess here, but I believe it is cause your front mount is blocking air from your ac condenser. Happens to me, but not as quickly as you describe.

 

[moi1463]

Just a wild guess here, but I believe it is cause your front mount is blocking air from your ac condenser. Happens to me, but not as quickly as you describe.

How did you fix the problem?

 

[t25fury]

sounds like your second fan (the ac fan) is not coming on.

 

[moi1463]

sounds like your second fan (the ac fan) is not coming on.

I have them on constantly via Link.

 

[knochgoon24]

Because of the funky way the DSM cooling system is setup, thermostats tend to run almost 20°F hotter than they are rated. Get the coldest one you can and you'll still probably be fine with a FMIC in front of it all.

The FMIC is probably your problem. Try to duct everything from your front bumper all the way through to your radiator. It will help keep the air going through it all.

Also make sure that your A/C condensor isn't direclty touching your radiator.

 

[moi1463]

Because of the funky way the DSM cooling system is setup, thermostats tend to run almost 20°F hotter than they are rated. Get the coldest one you can and you'll still probably be fine with a FMIC in front of it all.

The FMIC is probably your problem. Try to duct everything from your front bumper all the way through to your radiator. It will help keep the air going through it all.

Also make sure that your A/C condensor isn't direclty touching your radiator.

I have the coldest stat I can have, added the additive that's suppose to lower the temp even more. Condenser and radiator isn't touching each other. I don't have custom duct work for more cooling though. But I have checked for anything that might block the air passage. Is this a common issue with having a front mount because I searched and haven't really ran across a lot of people reporting the same issue. Would getting a mitsumoto radiator help with the cooling issue? I just don't get how it's getting that hot even when I'm going 70 on the freeway.

 

[crazyquik22023]

It's more than likely it's b/c of your FMIC blocking the airflow. Normally the faster you go the more air goes through your radiator. In your case, the faster you are going isn't really giving the radiator more air b/c it is getting blocked by the FMIC. So your engine is running at higher RPMS but is getting the same amount of airflow it is getting when cruising at lower speeds. I had the same problem. I run with my fans on all of the time and that helps my problem. I don't have a/c though. If your going to want to run a/c your going to probably have to create a duct so more air passes through the radiator. Your going to want to do something like this except you will probably want to make a duct from the bottom of your car and not the top unless you want to put a hole in your hood. http://www.dsmtuners.com/forums/custom-fabrication/386716-my-ducted-radiator-setup-road-racing.html Also drain and flush your radiator and replace with new coolant, like I said before. Also what temp thermostat are you running?

 

[moi1463]

It's more than likely it's b/c of your FMIC blocking the airflow. Normally the faster you go the more air goes through your radiator. In your case, the faster you are going isn't really giving the radiator more air b/c it is getting blocked by the FMIC. So your engine is running at higher RPMS but is getting the same amount of airflow it is getting when cruising at lower speeds. I had the same problem. I run with my fans on all of the time and that helps my problem. I don't have a/c though. If your going to want to run a/c your going to probably have to create a duct so more air passes through the radiator. Your going to want to do something like this except you will probably want to make a duct from the bottom of your car and not the top unless you want to put a hole in your hood. http://www.dsmtuners.com/forums/custom-fabrication/386716-my-ducted-radiator-setup-road-racing.html Also drain and flush your radiator and replace with new coolant, like I said before. Also what temp thermostat are you running?

Yea, I have flushed out the coolant when I changed the stats to the cooler one. I got the coldest one from O'reilly's. I think it's rated at 170 degrees or 180. I can't remember exactly, but I do remember asking for the colder one of the two they offer. I'm not really sure if I'll be able to make the cooling ducts due to the fact that I don't have access to all the resources required.

 

[nastyleak]

Have you opened the radiator after filling to make sure the coolant system is really full? Water Wetter seems to really help lower coolant temperatures, adding some of it that could be worthwhile.

 

[moi1463]

Have you opened the radiator after filling to make sure the coolant system is really full? Water Wetter seems to really help lower coolant temperatures, adding some of it that could be worthwhile.

Yes I've checked and rechecked many times to make sure I'm not low on coolant and I have water wetter added. It does seem to drop the temp with no ac, but still overheats with ac on.

 

[95talongirl]

this may be out in left field, but might be worth checking. Are the fans blowing in the correct direction? I know on the dodge neons that you can hook them up wrong and they will operate backwards. Had a friend of mine with a weird overheating problem (in the neon) kinda similar and it turned out to be the fans. !

 

[moi1463]

this may be out in left field, but might be worth checking. Are the fans blowing in the correct direction? I know on the dodge neons that you can hook them up wrong and they will operate backwards. Had a friend of mine with a weird overheating problem (in the neon) kinda similar and it turned out to be the fans. !

They are blowing in the right direction. and it feels like it's pulling a lot of air through the radiator, but I guess it's not enough or it's just pulling hot air through. Thanks though

 

[lb_gst99]

What are temps actually reading? As the number when your overheating. Also, what fans are you running?

 

[moi1463]

What are temps actually reading? As the number when your overheating. Also, what fans are you running?

I don't know the temps, but it goes above the half way mark and my CEL comes on. I have not had my laptop connected to link when it over heats so I can't tell you the exact numbers. All I see is the needle continues to climb and I just shut off the AC and it'll drop back down. I'm running two slim 10' fans that I got from O'reilly.

 

[liquidsilver]

Overheating after a fan change is usually caused by incorrect airflow direction. Flow is effected by polarity, blade direction AND pitch. I have the OEM cooling fan and a 10" eGay AC fan.

Even though both fans may turn in the same direction, and even if the blades are in the same direction, the pitch can be different. I wired my fans for OEM functionality but had to reverse the polarity on the AC fan...so it now turns the opposite direction but the airflow is correct. The pitch is what determines whether you are PUSHING or PULLING air.

 

[brandonzero0]

i had faced a similar problem after recharging my A/c. my issue was a clog in the high pressure line to the condensor. also happened in my envoy. especially when you let it sit for a while without it being charged with PAG laying in there. i used a good AC vaccuum pump to remove all the moisture and boil away any water inside the lines ETC and suck out any minut particles and then checked to make sure my A/C fan was functioning and it worked perfect after.

 

[DSM1G90]

Wondering if his compressor is getting ready to go with building up internal resistance being a 17yr old compressor. They do eventually die after age.