car overheats when AC is on
06-10-2008, 09:48 AM
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car overheats when AC is on for some reason this summer evertime i turn the AC on the car starts to over heat. first thing i checked was to see if the fans were coming on, wich they are second i checked the coolent level. that was fine. this happens when im sittin in a parking lot or driving down the road
help cant figure it out
help cant figure it out
06-10-2008, 03:25 PM
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for some reason this summer evertime i turn the AC on the car starts to over heat. first thing i checked was to see if the fans were coming on, wich they are second i checked the coolent level. that was fine. this happens when im sittin in a parking lot or driving down the road
help cant figure it out
help cant figure it out
A clogged up condensor. Over time sticks, little rocks, dirt, leaves and other **** gets all crammed into the front side of the condensor. As soon as you turn the A/C on the condensor gets warm, if the air cannot pass through it and go directly into the radiator to cool your coolant....you will simply get hotter and hotter until it goes into the red.
You need to take the radiator out, then grab a 2x4 piece of wood and SMACK the **** out of the condensor up against the wood, like 50 times HARD. You will see all kinds of **** fall out of the front of the condensor onto the ground.
Then you'll be fine. (This is assuming BOTH of your fans work on both high and low settings and come on when they are supposed to)
06-10-2008, 03:32 PM
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You can't tell if your condensor is dirty until you take the radiator out and get to look straight on to the font of the condensor. Mine was almost 90% clogged with debris, you couldn't see through it at all. After I banged all the crap out I could see through the entire thing no problem.
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06-10-2008, 07:53 PM
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You can't tell if your condensor is dirty until you take the radiator out and get to look straight on to the font of the condensor. Mine was almost 90% clogged with debris, you couldn't see through it at all. After I banged all the crap out I could see through the entire thing no problem.
06-10-2008, 10:16 PM
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No, I don't unhook anything from the condensor. The condensor just sits there but it can move alot. Just bang the **** out of it against the wood. Make sure you bang the outside top rim part of the condensor up against the wood, not the inner area.
06-10-2008, 10:17 PM
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06-11-2008, 01:27 PM
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When you put the A/C on and you have a clogged condensor, the condensor gets friggin HOT, and all that hot air gets pulled right through the fans and into the radiator, and that doesn't allow the already hot coolant that just transferred into the radiator when the t-stat opened to cool off. So when the cooler coolant that just transferred into the engine block/heads gets hot and opens the t-stat again to transfer the coolant....its gonna get a nice big gulp of HOT coolant that never got cool while it was sitting in the radiator. The engine just gets hotter and hotter and hotter, its a a losing battle. Engines are the best hot water heaters. Then at some point the t-stat WILL NOT close and this is when the temp guage looks like a windshield wiper going towards the red.
When your on the highway the ram air is also sufficient to keep enough air getting to the radiator to keep it cool even with the A/C on.
NOW....if the air space inbetween the condensor and radiator were shrouded to the point that it was sealed and the only way the radiator could get air is from the air that has already past through the condensor....THEN YES....you would be fucked no matter what.
This is not the case. So, from hot *** air getting pulled through the fans PLUS 110*-130* hot as hell air coming off the pavement via the air dam = overheat with the A/C "on" in city driving.
My temp gauge would go into the red if I let it in about 4 minutes, after I turned the A/C "on" in hot weather, in city driving. I simply turn it off and keep driving and it goes right back down to about 190* in another 5 minutes or so. If I din't use my A/C and drove like a friggin madman in city driving, the temps would never hit 220*. Turn the A/C "on" and I was fucked again.
He cleans the condensor and his problems are over.
06-11-2008, 01:53 PM
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i still think its the radiator, but it wont hurt to clean the condensor. when the radiator is clogged and he turns on the A/c there is much more load on the motor, i bet if he drives up a hill or finds a way to put stress on the motor like how the A/C is doing, it will overheat with the A/c off!
06-11-2008, 02:14 PM
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And yes, I've had my PCM scanned while driving and the temp guage is pretty close to accurate, its about 10-15 degrees low.
06-11-2008, 02:18 PM
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i still think its the radiator, but it wont hurt to clean the condensor. when the radiator is clogged and he turns on the A/c there is much more load on the motor, i bet if he drives up a hill or finds a way to put stress on the motor like how the A/C is doing, it will overheat with the A/c off!
Its very rare and very hard to have a clogged radiator, what there to clog it. Does he have 150,000 miles on it without having ever changed the coolant? Does he have oil or power steering fluid getting into the coolant? If not, there's really nothing else that can clog a radiator, except maybe a rag.
If he can see the coolant flowing when the t-stat opens, with the rad cap off, its fine.
06-11-2008, 02:48 PM
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Then he should go for a drive with the A/C "off" and beat the **** out of it for about 15-20 minutes. I have a built 427ci stroker, just a tad under 500 RWHP and when my condensor was clogged I could beat the **** out of it in 90* south Florida weather and it would never get hot.
Its very rare and very hard to have a clogged radiator, what there to clog it. Does he have 150,000 miles on it without having ever changed the coolant? Does he have oil or power steering fluid getting into the coolant? If not, there's really nothing else that can clog a radiator, except maybe a rag.
If he can see the coolant flowing when the t-stat opens, with the rad cap off, its fine.
Its very rare and very hard to have a clogged radiator, what there to clog it. Does he have 150,000 miles on it without having ever changed the coolant? Does he have oil or power steering fluid getting into the coolant? If not, there's really nothing else that can clog a radiator, except maybe a rag.
If he can see the coolant flowing when the t-stat opens, with the rad cap off, its fine.
06-11-2008, 05:00 PM
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o man, if u see what that dex crap does to our cooling systems, u would know why the radiator would get clogged! but it is not only from that , why do u think some companies sell a radiator filter for cars and trucks, and why do semi trucks have a radiator filter standard on some trucks, they look just like an oil filter but it for coolent!
This is plain and simple troubleshooting. Its been about a dozen guys problems that I've helped down here over the years. It drives them nuts trying to figure it out until I tell them what it is.
Its pretty simple...if your engine overheats ONLY when you turn the A/C "on".....its an A/C system problem that is causing the engine/coolant to heat up. It has absolutely NOTHING to do with the coolant system. Our coolant systems can handle 427ci-454ci built engines, mine is a perfect example. But with a clogged condensor, you're screwed. With a clogged radiator your ALWAYS going to over heat, even in the winter time in 10* weather. Ever see what happens to a condensor in a house when it gets dirty...the house blows hot air because the entire system gets hot. Same thing happening here.
Dex is **** though. I've been using 90% water and about 1 quart of Dex for lubrication. Its been perfect for 5+ years. Radiator is spotless inside, looks new.