Cooling issues -- How to beat the heat?

AMD[H]unter

Registered User
Hey, all, I have a small issue with my car. With the A/C on, cruising around, staying out of the throttle, my temps get up around 220-230 degrees. This seems a little high to me, but I don't know for sure if it is too hot. Without the A/C on, it stays around 190-200 degrees. I have done the high-speed fan mod to it, and I also have an intercooler fan on it (doubtful if this helps any at all - maybe the little bit cooler air charge helps?). I just flushed the coolant system, and it dropped it a little, but I was wondering if there is any way to get it to stay around 200 degrees with the A/C on. I am still on a stock radiator, too. Any ideas?
 
I tried everything from an oversized air dam to recoring the radiator and I was even going to cut louvers in the hood. Mine didn't start running cool until I finally gave up and switched to a Griffin aluminum radiator.

David
 
I tried everything from an oversized air dam to recoring the radiator and I was even going to cut louvers in the hood. Mine didn't start running cool until I finally gave up and switched to a Griffin aluminum radiator.

David

What kind of outside air temperatures were you noticing this in? What were your engine temps? was this just at idle or while driving also? I have pretty well the same setup as you, with just a new stock radiator. I am hoping with both fans I will be ok. I have a 180 degree thermostat and my pusher fan is wired to a switch in the car.

Chris
 
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i flushed the system 195* thermostat. bottle of water wetter and filled the system up w/all water(better heat disper.) removed the a/c condensor and have the fan on a switch..i've found the trick is to not let it got that hot to begin with. so for the most part,unless its 60*in the morning the fan is on all the time. mine never reaches 170 now.
but 220 is when the fan's are set to turn on. so i'd say 220 is a edge of normal temp to run. i wouldnt want to run that temp for long periods of time,but thats just me. :)
 
What kind of outside air temperatures were you noticing this in? What were your engine temps? was this just at idle or while driving also? I have pretty well the same setup as you, with just a new stock radiator. I am hoping with both fans I will be ok. I have a 180 degree thermostat and my pusher fan is wired to a switch in the car.

Chris

Chris,

At anything over 75 degrees my coolant temp would slowly start climbing to between the R & M (about 210 degrees) with the AC turned off. Driving on the highway caused it to heat up the fastest. Once it got hot it wouldn't cool back down unless I shut it off for a while or it started raining. I had the same dual fans with 180 thermostat that I'm using now.

Now I can drive in pretty much any temp at any speed and the needle never goes past the N (about 185 degrees). I still can't use the AC if outside temps are over 90 degrees or it will start getting hot, so I almost never turn it on.

David
 
This is in temps from 80-100 degrees in stop and go traffic, and I forgot to mention that I have a 180* t-stat. so basically, I need an aluminum radiator?
 
Chris,

At anything over 75 degrees my coolant temp would slowly start climbing to between the R & M (about 210 degrees) with the AC turned off. Driving on the highway caused it to heat up the fastest. Once it got hot it wouldn't cool back down unless I shut it off for a while or it started raining. I had the same dual fans with 180 thermostat that I'm using now.

Now I can drive in pretty much any temp at any speed and the needle never goes past the N (about 185 degrees). I still can't use the AC if outside temps are over 90 degrees or it will start getting hot, so I almost never turn it on.

David


Well, for now I'll just have to cross my fingers and hope that mine cools better then yours did. I don't understand why the car gets hot while you are moving though, should stay cool while moving at least! You think it has anything to do with how the main fan is mounted to the radiator? To me if the car is getting hot while moving over 40mph, maybe that fan is not keeping up with the air that is needing to be pulled through.
 
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because the airflow to the radiator and intercooler are kind of poor. dont forget the cooler your intake temps the cooler the engine will run too,i also have a cold air intake(filter in the fender) that prob. wouldnt help as much as say,a fmic,or a fan on the intercooler. also you could heat wrap the lower intercooler pipe.
 
Well, for now I'll just have to cross my fingers and hope that mine cools better then yours did. I don't understand why the car gets hot while you are moving though, should stay cool while moving at least! You think it has anything to do with how the main fan is mounted to the radiator? To me if the car is getting hot while moving over 40mph, maybe that fan is not keeping up with the air that is needing to be pushed through.

The motor generates more heat at cruise speed than it does at idle.

David
 
I got good results with the two 'sandwitched' GM air dams on my 89. Drove the car in hot temps (when it ran:mad: ) and the teps were always cool. This was with the old stock rad, and regular 50/50 coolant mix, Shaw 180* tstat...ofcourse, i'd have the low speed fan on once the car would reach operating temp, but i never 'had' to turn the hi speed on.
 
Just to add a little bit to this... When I first bought my SC, it ran towards the "m" almost all the time. Regardless if I had the fan switched on all the time or not at all. As Dave said, it too also got hotter when the AC was turned on too.

I have since went with a 180* thermostat, and had my car tuned, which in turn Dave set up the chip to account for the 180 thermostat. So now the fans turn on earlier and keep things cooler. With the setup I have now, whether the AC is on or off, my temps never exceed 195* (Autometer Gauge)

Keep in mind that I do not have a FMIC blocking any flow to the radiator though, so Im sure that has something to do with keeping my car cooler.

Dont know if this will help you at all, but figured Id throw it out there.

Mike
 
i flushed the system 195* thermostat. bottle of water wetter and filled the system up w/all water(better heat disper.) removed the a/c condensor and have the fan on a switch..i've found the trick is to not let it got that hot to begin with. so for the most part,unless its 60*in the morning the fan is on all the time. mine never reaches 170 now.
but 220 is when the fan's are set to turn on. so i'd say 220 is a edge of normal temp to run. i wouldnt want to run that temp for long periods of time,but thats just me. :)

All water?

You just lowered your boiling point temperature way down. Antifreeze is not just to protect your coolant from freezing. It actually helps to prevent boiling and raises that point when under pressure, which is 16 psi for our cars.

Also, your car will stay in startup fuel strategy for along time because your temp doesn't go up over 180, unless you have a chip or tuner that will allow you to lower that temp..... hows the gas mileage these days?

Anyways....

For those that just drop a 180 tstat in and do nothing else..... our rads are too small for continuous flow so we need to hold coolant in there for a short time to allow transfer of heat. Running a 180 tstat without changing how the fans run can actually cause your car to run hotter because it doesn't linger long enough in the rad to transfer enough heat, so the temp just keeps rising.

Dave Dalke has an excellent article on here explaining the best operating temps for our cars which seems to be around the 200 mark if I recall. The stock fan on temps are way too high. I also see a prob with running the low speed fan all the time like alot of folks do because that sucker draws alot of current even on low speed, which makes your alternator work alot more which is robbing HP from your motor, which will generate more heat and so on.

I can drive the heck out of my car in 100 degree weather and my running temp hovers around 200. I have the stock rad, stock tstat, stock fan setup, stock air dam, 50-50 mix, and water wetter. If I'm running the a/c the car actually runs a bit cooler.

The things I make sure of is changing my coolant every year. I pull out the rad and and back flush the a/c condensor using a garden hose to allow air flow.... (you'd be surprised how much crap gets stuff'd in there) which actually allows your a/c to run more efficiently. I have also setup my EEC Tuner to turn on the low speed fan at 200 and kick over to the high speed fan at 210.

Now keep in mind, my car is still stock for the most part. Dave Neibert's car is very built, and I can understand needing that rad he has as the stock radiator is too small for him for the amount of power he has ;) , after all, more power more heat.
 
well,i made this thread here, http://www.sccoa.com/forums/showthread.php?t=89965&highlight=fan+time and never directly got that response. but i started the thread b/c not getting out of closed loop/startup stratey did cross my mind because my car does seem to run very rich. as far as the all water comment, i've read several times on here that you should run all water w/a bottle of water wetter...if your suggesting i should add coolant i'll most cerrtainly take your advise as i'm not doubting you.
 
Water is one of the most efficient heat transfer fluids available. It has a specific heat almost twice that of glycol. This means it can hold almost double the amount of heat that glycol can.

The only reason to use antifreeze is the antifreeze protection. If it wasn't for the anti-corrosion additives all you guys in the south should be running straight water. Certainly a 50/50 mix is only required up here in the great white north and not in the summer time.

http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html

sean
 
thats what i remember reading almost word for word..lol,most of been you who typed it:)
good link btw,i had no clue that even at 50/50 it could freeze @-36
 
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Water is one of the most efficient heat transfer fluids available. It has a specific heat almost twice that of glycol. This means it can hold almost double the amount of heat that glycol can.

The only reason to use antifreeze is the antifreeze protection. If it wasn't for the anti-corrosion additives all you guys in the south should be running straight water. Certainly a 50/50 mix is only required up here in the great white north and not in the summer time.

http://www.engineeringtoolbox.com/ethylene-glycol-d_146.html

sean

I'd rather not take the chance of the car hitting 212 deg F and have the water start boiling inside the motor when the fan on temps don't come on till 220 :eek: compared to a 50% mix and boiling point of 225 deg F. Add pressure to this and it raises those boilings points but not by a whole lot at 16psi.

Its your car ;)
 
Here's my formula for success in the South Texas summers. I did this to my 89 automatic daily-driver, and never had ANY problems whatsoever. Even running the A/C and sitting in afternoon rush-hour traffic.

A) Confirm the cooling system is in PRISTINE condition; no scale, sludge, debris, etc. The radiator in my car had a small "weep" on the bottom tank, so I replaced it with an aftermarket unit from Radiator Express.
B) Assuming the engine is original with no modifications (I noticed the thread-starter has a 10% SC O/D pulley, which will add heat).

1) Flush cooling system with hoses disconnected.
2) Install a quality brand of 180 deg. thermostat.
3) Install a mixture of 25% E/G 75% distilled water + 1 bottle WaterWetter (your climate may preclude this weak mixture of E/G).
4) Assure that the air intake area, A/C condenser and radiator are completely clean and free of any debris; bugs, dirt, stones, grass, etc. Then when you're satisfied, clean it again.
5) Confirm that your radiator fan is functioning properly.
6) MAKE SURE you have the factory air dam underneath the front facia. Mine was missing, so I ordered the GM part number, and modified it to fit. It's taller than the original, so it may be marginally more efficient. It's important to have an air dam.

That's it. As long as the car is not modified, these changes should work well. When new, the cars didn't have gross cooling problems, so it's mostly related to restoring/keeping the cooling system in good shape.

As has been stated, there is no better heat tranfer fluid than straight water. When I next change the coolant in my white car, I'm going to find out just how little E/G I can get away with from a protection standpoint. I'm hoping to go with about 10% - 15% + WaterWetter, and add some water pump conditioner, corrosion protectant, etc.

JD
 
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I agree, the condenser really saturates the radiator with excess heat with the a/c on. Air dam is a must at highway speeds as our front ends wont get enough air through the radiator without one. I flushed my system today and filled it with water wetter and straight water; any coolant in the system is only from what was left in the block. I charged the a/c and have been running it all day in 100 degree heat. It is running substantially cooler with the water wetter and no or minimal coolant. I did however inspect my cooling system and have zero leaks and the old coolant that came out was relatively clean and free of sludge. The water wetter simply works. Of course out here in the desert southwest there is next to no humidity, unlike southeast Alabama. I'm sure that would have some effect on the heat transfer.
 
I'd rather not take the chance of the car hitting 212 deg F and have the water start boiling inside the motor when the fan on temps don't come on till 220 compared to a 50% mix and boiling point of 225 deg F. Add pressure to this and it raises those boilings points but not by a whole lot at 16psi.

Don't forget that 16lb cap is guage pressure. That = 30 lbs absolute. This = an approximate boiling point of 250 degrees f.

Lots of head room for boiling over.

As i said it's the corrosion protection and freezing protection that you need antifreeze for.

sean
 
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