Over Heating and Over Cooling???
01-03-2009, 10:48 PM
#1
Thread Starter
Join Date: May 2008
Location:
Posts: 9
Over Heating and Over Cooling???
Hey guys, yeah my first post after searching this site for a clear answer and I am still stuck and baffled. I have a 72 Fastback with a 302. My problem is this, on a 70 degree day in town traffic that is bumper to bumper the car wants to over heat(220). I expect it to run warm cause not getting a lot of fresh cool air into front of car. I put a lower stat in (160) hoping to correct the problem and no luck. The rad is not stock and I honestly don't know where it came from. I have flushed the system as well.
Now in the winter time and actually tonight took the car out for a cruise and it was about 30 outside, but car would not register above 110 on the temp gauge. If I sat at a light it would go up so in know the gauge is working.
Now my question is how do i stop the over heating in the spring/summer and keep from cooling too much in the winter?
I have considered going to a BECOOL rad but that would probably correct my summer but would make my cold weather riding worse than it is. I have a 17" flex fan and I am running 50/50 on the antifreeze. Do i look at electric fans? Waterpump? Any insite will be greatly appreciated. It has taken my 12 years to get my mustang and finally have it, but it is not turning into the dream i was expecting.
Now in the winter time and actually tonight took the car out for a cruise and it was about 30 outside, but car would not register above 110 on the temp gauge. If I sat at a light it would go up so in know the gauge is working.
Now my question is how do i stop the over heating in the spring/summer and keep from cooling too much in the winter?
I have considered going to a BECOOL rad but that would probably correct my summer but would make my cold weather riding worse than it is. I have a 17" flex fan and I am running 50/50 on the antifreeze. Do i look at electric fans? Waterpump? Any insite will be greatly appreciated. It has taken my 12 years to get my mustang and finally have it, but it is not turning into the dream i was expecting.
01-03-2009, 11:07 PM
#2
3rd Gear Member
Join Date: Jul 2006
Location: Wyoming
Posts: 800
A new radiator with an electric fan would work to correct both problems I think: higher efficiency cooling during warm temps, and the option to shut off the fan and keep in the heat during cooler temps. The trouble is this method is expensive and can be frustrating to install, but it works.
01-03-2009, 11:43 PM
#3
2nd Gear Member
Join Date: Jun 2007
Location: Oregon USA
Posts: 196
Just my $0.02 worth.
The 160 degree Tstat is too low. You should probably have a 180 degree Tstat. The 180 degree Tstat will help your winter temps run warmer by preventing water flowing to the radiator at temps below 180 degrees.
As to your summer issue. Do you have a shroud around the fan? Also the Flex fan may be "flexing" too much and not moving enough air when you really need it too.
The 160 degree Tstat is too low. You should probably have a 180 degree Tstat. The 180 degree Tstat will help your winter temps run warmer by preventing water flowing to the radiator at temps below 180 degrees.
As to your summer issue. Do you have a shroud around the fan? Also the Flex fan may be "flexing" too much and not moving enough air when you really need it too.
01-04-2009, 08:13 AM
#5
4th Gear Member
Join Date: Oct 2007
Location: Central Illinois
Posts: 1,751
I am going to go with plcdude on this one. A reasonably stock engine should not have this problem. It probably is being caused by a modification like the flex fan. The carboard in front of the rad is indeed somthing we commonly did back in the olden days but it was more for getting the car up to temp and the heater working faster than for long term temp regulation. Back then you could drive for 15-20 minutes before the heater started doing anything at all. And that was on the really cold days...zero or less. 30 degrees just should not be a problem.
01-04-2009, 08:35 AM
#6
4th Gear Member
Join Date: Sep 2008
Location: Connecticut
Posts: 1,839
I have a couple of thoughts:
1. Are you sure you installed your thermostat correctly? The bulb goes towards the engine.
2. How old is your water pump and is it operating correctly?
3. Overheating when idling, but running correctly at speed is usually an indication of an underperforming fan or lack of a fan shroud (speed gets enough air through the radiator to cool the engine even at higher engine rpm, while fan can't even at lower engine rpm). If you don't have a shroud, get one.
4. Your lack of operating temp on a cold day is an interesting one. This almost says you have too much radiator, but your thermostat should regulate this. I think your new thermostat is bad.
So, I think you should get a 180 thermostat and test it in a pot of water on the stove with a thermometer before you install it (you would be amazed how many either don't work or open at the wrong temp). Once you know it works correctly, install it with the bulb towards the engine. Then get a fan shroud if you don't have one.
Also, a picture of your set up would help, plus we want to see your car!
1. Are you sure you installed your thermostat correctly? The bulb goes towards the engine.
2. How old is your water pump and is it operating correctly?
3. Overheating when idling, but running correctly at speed is usually an indication of an underperforming fan or lack of a fan shroud (speed gets enough air through the radiator to cool the engine even at higher engine rpm, while fan can't even at lower engine rpm). If you don't have a shroud, get one.
4. Your lack of operating temp on a cold day is an interesting one. This almost says you have too much radiator, but your thermostat should regulate this. I think your new thermostat is bad.
So, I think you should get a 180 thermostat and test it in a pot of water on the stove with a thermometer before you install it (you would be amazed how many either don't work or open at the wrong temp). Once you know it works correctly, install it with the bulb towards the engine. Then get a fan shroud if you don't have one.
Also, a picture of your set up would help, plus we want to see your car!
01-04-2009, 08:39 AM
#7
1st Gear Member
Join Date: Mar 2008
Location: Ga
Posts: 126
+1 on the thermostat, and the fan shroud.
Installing a fan shroud on mine made a noticeable improvement. It runs cooler in warmer months, especially in stop and go traffic.
Cold months - A higher temp stat will lock the coolant into the block for a longer period of time to allow it to come up to temp.
These are relatively easy and inexpensive things to try first. Still, to me it sounds like you also might have a circulation problem with the radiator.
Installing a fan shroud on mine made a noticeable improvement. It runs cooler in warmer months, especially in stop and go traffic.
Cold months - A higher temp stat will lock the coolant into the block for a longer period of time to allow it to come up to temp.
These are relatively easy and inexpensive things to try first. Still, to me it sounds like you also might have a circulation problem with the radiator.
01-04-2009, 09:25 PM
#8
Thread Starter
Join Date: May 2008
Location:
Posts: 9
Okay i will get the picture of setup and car.
And the answers to your questions:
Yes I have a fan shroud.
Yes stat is in correct
I did have a 180 stat but i figured with it being hotter in summer could help out with the temp on the engine the 160 stat would be okay. Basically I was tryin to offset the temp with the over heating but didnt work I guess.
2 more question for you guys. Should i invest in a fan shroud for the mustang and pay more money, or is there a particular year, make, model car where a fan shroud would fit just as good and be as effective. I am willing to pay for anything, but i am sure everybody knows if you can save a buck go ahead and save it! Last any opinions on fans?
And the answers to your questions:
Yes I have a fan shroud.
Yes stat is in correct
I did have a 180 stat but i figured with it being hotter in summer could help out with the temp on the engine the 160 stat would be okay. Basically I was tryin to offset the temp with the over heating but didnt work I guess.
2 more question for you guys. Should i invest in a fan shroud for the mustang and pay more money, or is there a particular year, make, model car where a fan shroud would fit just as good and be as effective. I am willing to pay for anything, but i am sure everybody knows if you can save a buck go ahead and save it! Last any opinions on fans?
01-05-2009, 08:14 AM
#9
5th Gear Member
Join Date: Mar 2005
Location: Marquette Mi
Posts: 3,566
First. 220F isnt overheating, 250F would be overheating. As you increase coolant pressure you raise the boiling point of the coolant. Also the mix of antifreeze/coolant and water has a higher boiling point as well. So at 220 you arent hurting anything and you are actually helping a few things in your engine. People just get it in their head that anything over 200 is way to hot for an engine, it isnt.
Second. Fakesnakes is right about getting warmer while sitting still is an indication of the fan not pulling enough air. Still if it doesnt go over 220F then you are still safe.
Third. A 160F thermostat is nice for drag racing where you arent driving it that much and you want it cold as possible while running gasoline. As you have found out it doesnt make the heater work well in even 50F weather. Put a 180 or 195 back in it for the winter and watch the gauge, if it stays under 220F you are golden, if it goes over 250F then you have issues.
Fourth. There is more to it than running cool, your engine will get better mileage if it is warmer than 190F compared to 160 or colder. Additionally, condensation builds up in the crank case through the natural process of heating and cooling, so you end up with water in your oil because water vapor is in the air around us. If your oil doesnt go over 212F the water stays in the oil and makes all sorts of interesting things happen. You NEED to get the OIL temp over 220F for the engine to function properly and rid itself of water in the oil. Oil temp is usually higher than coolant temp since oil has to cool bearings and and other wear surfaces, so its getting beat up the entire time the engine is running.
Last. If you arent running a catch can with a hose through the cap that will siphon coolant back into the engine as it cools, you are getting air in your radiator. You dont want air in there since air doesnt transfer heat as well as water. Like most things, water expands when it gets warmer, and contracts when it cools. When hot it will push coolant out because there isnt enough room for it, if you dont catch it and allow it to return to the engine, it will pull air back in rather than coolant.
Fan, thermostat, shroud, and catch can.
I run electric fans because I like to be able to cool the water off at the track while the engine isnt running, start it for a few seconds and circulate the water a bit. You dont need to do that, but a decent electric with a thermostatic switch to control it wouldnt hurt.
There is a BeCool radiator, twin fans, and the thermostatic switch cooling the 455 in my GTO, it used to go over 250F in traffic, now it stays right where I want it at idle, but it does cool off some on the highway. Since its been on straight ethanol since May, it hasnt gotten warm enough to boil the water out, so I need to change things again to keep some heat in the engine. If you are really worried about it running hot, and you have an E85 station near you, I can show you how to modify your carb so you can run ethanol. Any engine that is boosted or has over 11:1 compression would benefit greatly from running ethanol, you can still get it to do much better than gas if you are stuck with a low compression engine, it just takes a bit of work.
Second. Fakesnakes is right about getting warmer while sitting still is an indication of the fan not pulling enough air. Still if it doesnt go over 220F then you are still safe.
Third. A 160F thermostat is nice for drag racing where you arent driving it that much and you want it cold as possible while running gasoline. As you have found out it doesnt make the heater work well in even 50F weather. Put a 180 or 195 back in it for the winter and watch the gauge, if it stays under 220F you are golden, if it goes over 250F then you have issues.
Fourth. There is more to it than running cool, your engine will get better mileage if it is warmer than 190F compared to 160 or colder. Additionally, condensation builds up in the crank case through the natural process of heating and cooling, so you end up with water in your oil because water vapor is in the air around us. If your oil doesnt go over 212F the water stays in the oil and makes all sorts of interesting things happen. You NEED to get the OIL temp over 220F for the engine to function properly and rid itself of water in the oil. Oil temp is usually higher than coolant temp since oil has to cool bearings and and other wear surfaces, so its getting beat up the entire time the engine is running.
Last. If you arent running a catch can with a hose through the cap that will siphon coolant back into the engine as it cools, you are getting air in your radiator. You dont want air in there since air doesnt transfer heat as well as water. Like most things, water expands when it gets warmer, and contracts when it cools. When hot it will push coolant out because there isnt enough room for it, if you dont catch it and allow it to return to the engine, it will pull air back in rather than coolant.
Fan, thermostat, shroud, and catch can.
I run electric fans because I like to be able to cool the water off at the track while the engine isnt running, start it for a few seconds and circulate the water a bit. You dont need to do that, but a decent electric with a thermostatic switch to control it wouldnt hurt.
There is a BeCool radiator, twin fans, and the thermostatic switch cooling the 455 in my GTO, it used to go over 250F in traffic, now it stays right where I want it at idle, but it does cool off some on the highway. Since its been on straight ethanol since May, it hasnt gotten warm enough to boil the water out, so I need to change things again to keep some heat in the engine. If you are really worried about it running hot, and you have an E85 station near you, I can show you how to modify your carb so you can run ethanol. Any engine that is boosted or has over 11:1 compression would benefit greatly from running ethanol, you can still get it to do much better than gas if you are stuck with a low compression engine, it just takes a bit of work.
01-05-2009, 12:46 PM
#10
Thread Starter
Join Date: May 2008
Location:
Posts: 9
Okay guys, for the ones that wanted some pics of setup and car here ya go. Today I did start up the car and get the temp up. The stat is opening and closing at the correct temp. Now if I raise the hood about a foot the temp would go down. If i left the hood latched closed the temp would go up. Well makes since because the heat is excaping from under hood if up. Of course you guys mentioned this already but, i agree that the fan is not pulling enough air in through the rad to cool off the motor. I put my hand in front of the rad and I can feel a light draw but i think a new fan would improve it. Do any of you object to starting with this first? I feel if she can keep temp at idle in winter the summer its suicide. Thanks for all the feedback and opinions, its greatly appreciated.
http://www.cardomain.com/ride/3219228
http://www.cardomain.com/ride/3219228