- Wed Sep 26, 2012 11:24 am
#316545
Cooling System:
Major Components: Radiator, Water Pump, Thermostat, Hoses, Heater Core, Engine.
Question: "My car overheats, what's wrong?"
1. Does your car have a leak? Is it losing coolant? The BEST way to figure this out is to use a pressure tester, or have your car pressure tested. What this does it pressurises your cooling system and allows you to look for a leak. Don't forgett to look in the heater core area (coolant on passenger side floor, or smell of coolant when heater is on, fogged up windows).
If you find your leak, fix it first. If you're loosing coolant and you can't see the leak, you either A. Missed it. or B. It could be leaking internally (headgasket, radiator/trans cooler, etc.)
Please fix your leak first. Running low on coolant will cause the car to overheat, and also introduce air into the system, air pockets can cause overheating, and even cause oveheating while the guage shows correct tempurature, and ALSO not allow your fans to kick on (Coolant sensors and fan switches work off of COOLANT tempuratures, not AIR temps. In other words, if there is an air pocket at 600 degress and it's in the area of a sensor, the sensor doesn't care and recognise it).
Note: Headgaskets USUALLY go between the #2 and #3 Cylinder. If your loosing coolant and don't see it, pull the plugs and especially look at the #2 and #3 cylinders. One clue may be to compare them to the others. If one piston looks Shiny and/or Super Clean. Chances are you have a headgasket issue and the coolant/water is steam cleaning your piston. That's just one check.
Another common symptom of headgasket failure is the immediate pressurizing of the cooling system. If the coolant is FULL and you start the car with the radiator cap OFF, it will shoot out the radiator. If so, it's not good news for your headgasket.
Yet another test is a Carbon Monoxide test. Some SLOW or just starting headgasket leaks can be found with a tester that goes on your radiator, the car is started, and if carbon monoxide is in the system, the liquid will change color, if so, the headgasket is bad and allowing combustion fumes into the cooling system.
Headgaskets don't always rear they're ugly head all the time. Sometimes it's while the car is cooling down it will leak, sometimes under heavy load, etc. It's not always a "as soon as it leaks it keeps leaking" type thing. It can come and go with tempurature change in the engine. But either way, as soon as it starts to go, it needs replaced, it will not get better.
If you replace a headgasket, ALWAYS have a machine shop check it and surface if needed. If you don't have the proper surface, your just causing yourself problems in the future.
2. No leaks, my car still overheats, what's wrong?
A. Does your fan kick on?
1. NO. My fan does not kick on.
The fan on most Honda's kicks on around 190° and off between 182°-188°. Most Domistic cars fans don't kick on till about 224°.
If the fan is NOT coming on and you DON'T have a leak, you need to check Grounds, Relays, Fan, and Coolant Temp Switch, perferably in that order. Check a Honda manual on how to check some of these. There are some simple steps you can do with a multimeter.
2. YES. My fan does kick on.
Ok, so your fan is working, and you you DON'T have a coolant leak. Well it could be a headgasket right? If your not losing coolant then NO, it's not likely a headgasket.
a. A thermostat is a possibility, but haven't seen to many problems in a Honda. If you replace the t-stat (inexpensive) then make sure you get a Honda Part.
Note: Please just put a Honda T-stat in your car and knock that out of the overheating equation. NOT running a T-stat is not a good idea at all. For one, the system was DESIGNED for the t-stat to be there and working properly. Removing the stat on SOME CARS can disrupt the proper flow (not going to get into this right now, but it does happen). Not running a T-stat also causes the Engine Management to run differently. You'll use more gas, and possibly hurt power. Just don't do it.
b. Another possibility is the radiator. But it doesn't leak right? Doesn't matter. A radiator can cause overheating in 3 ways.
1. It leaks (duh )
2. The fins are VERY corroded and missing. Missing fins and a half corroded away radiator does not allow it to cool the coolant properly, and YES, can cause overheating.
2. Blockage. ONE way to check for blockage is a "Infared" Temp Gun. You can check the radiator in several area's and see if there is a major difference.
Now you can STILL have flow, but blockage at the same time. Don't be misled. Partial Blockage can block MUCH of the flow of coolant, but you can still see it "flowing". Years of corrossion and "stop leak" contribute to blockage. If while taking the radiator out you notice it's EXTRA heavy, chances are it has a lot of sediment and should consider replacing. If you do, consider flushing the system well.
c. A water pump usually does not cause overheating (if not leaking) on a Honda. There are some other cars in which the Water Pump "impellers" disinagrate over time, but not usually on Jap. cars. MAJOR sediment gumming up the impellers would be the only case. I'd say darn near unseen on a Honda, but possible.
Cooling System Tips: If your car is coming close to overheating. Turn on your heater, and put the blower on full blast. Your heater core is another small radiator more or less, it can assist in cooling.
If your car goes into the red. PLEASE SHUT THE CAR OFF NOW! Don't drive your car, pull over and shut it off. Why? Because it could be something very simple, but if you keep driving while overheating, you can quickly destroy everything, YES, you can destroy just about everything depending on the extent and temp. Headgasket, head, rings, etc etc etc.
If you really care, use only Honda coolant and parts. Now many backyard hacks on hear don't have a clue, but it has been proven time and again, not just with the cooling system.
Honda Coolant for example has a much less corrosive nature than most other coolants, and last longer. There have been studies that show this. Why do you care? Because less corrossion means less eating away of the gaskets, hoses, radiator, etc. It really does make a difference in the long run.
Use a Honda T-stat as well. Don't cheap out on this.
Last Tips: I see many on HT cheap out and try to "Hack" their way to freedom. I understand some like to keep things cheap, but you usually cause more problems. Do things right, do them once, and it is THEN much easier to solve problems. This goes for the cooling system and many other aspects of the car.
The less you do things properly, the more variables and problems you introduce into the equation.
posted by: juevi
SOME BASIC INFO:
Less than 40% off the heat generated through combustion is turned into Horsepower (this term is called thermal efficency, now this is only applicable to a N/A vechile, if you are F/I this number will change drasticly anywhere from 50% - 200% almost 2x as much).
This means that 60% of the heat occuring from this air fuel mixture is let out through your exhaust and through your cooling system.
Now lets start with the basic components of the cooling system are.
1. Radiator
2. Fan (Electiric / Belt driven)
3. Water Pump
4. Cap
5. Thermostat
6. Hoses
7. Coolant
Now these are all equal in importance, no one is greater then the other.
Now lets check out the basic out the basic functions of these.
Radiator- Exchange the heat into the atmosphere in exchange for cold air. This is called a heat exchanger, Heat exchanger are devices where 2 or more moving fluids streams exhcange temperture. with out mixing.
Fan- The fan is an assistant in moving air toward the radiator accompanied by the fan shroud. Now in most cases the fan is an excessory item the reason I say this becuase most fans do not kick in at highway speeds on in the city becuase air movment is so great at high speeds so in theory you can basicly get rid of your fan at the track for weight saving, but be careful of the temperature and the number of passes you are making.
Water pump- Is like the heart, keeps the circulation with out it you can will die.
Cap- To keep the system under a constant flow the cap keeps the system closed to the atmosphere, and also keep the system under a certian pressure.
Thermostat- A temperture controled valve allowing coolant to pass through to the radiator when hot to allow heat exchange and closed to allow for warm up when cold.
Hoses- Like the vesels keep everything connected.
Coolant- The carrier, that allows for all of this to happen.
When to upgrade radiators?
This question has baffled many of us. The basic guide line is if your vechile is making 10% or less Horsepower then stock and you never really beat on your vechile you really don't need a upgrade. But if your radiator is more then 4 years old and you are generating about 20% more power than stock or do and kind of track/ road racing you should consider and upgrade.
There are so many out there, which radiator to pick?
When choosing a radiator you must understand there are alot of factor that play apart of this process such as core lenght, width, thickness, tube thickness, tube spacing and fin density. Now I can't tell you exactly what to get becuase there isn't a basic guide for this. All I know is companys have spent thousand into research, and have designed certian radiators for certian applications for example a radiator designed for track is going to have a better cooling capacity then a drag. So call the companys and ask. But in general a equal balance of all the properties makes the best radiator.
Now updating fan?
If you are and elecritc fan which most of us are we really don't have any options for update unless there is a double electric fan some where out there that I am un aware of so keep it as it is or find a bigger fan.
Coolant.
For coolant to be able to carry heat it must remain in its' liquid form and not turn into a vapor this is very improtant.
Let us take into conciderator Boilng point. Pure water boils at 100 degrees celcuis
and freezes at 0 degrees celcius, this is all under normal atmposphere conditions. Now if we apply pressure to like 14.7 psi the water will not boil till 121 degrees Celsius, and when you install a 18.9 psi cap water Will not boil till 124 degrees celcuis.
Wait, but pressure is not the only important part of this, mixture is just as important. Ethylene-glycol AKA Antifreeze is a fluid that has chemical additives to prevent rust and to lubricate the water pump. Now using a mixture of water and anti-freeze has its advantages and disadvantages, Using a 33% solution will raise the boiling point 4 degrees celcius, and using a 50% solution will raise the boiling point 9 degrees celcius. But here's the bad Antifreeze does not have the same heat capacity as water it is actually 20% less. So a 50/50 mixture (1 quart) that passes through the system will only be able to carry 80% of the heat, while the pure water can take nearly all away. So this led to the sports world to use pure water and rust inhibitor and boosters that reduce surface tension.
In the bigger picture though when water freezes it increeses almost 9% in volume, and if this where to happen it could cause major harm in cold weather, but here's the saviour again, a 33% mixture will drop the freezing temperture to nearly 16 degrees celcius and a 50/50 mixture will drop the point to almost 37 degrees celcius.
So now I bet you're in a world of wonder of what to fill your car with?
First you must determine the lowest temperture you are going to encounter and then add the least amount of Ethylen-glycol in cordination with this, usally there is a chart for you to fallow on the back as a guideline. But if you are using less then 50/50 mixture please use the additives.
So in the end my friends don't forget to think about the cooling system, If you do be prepared for a multitude of problems.
posted by: q45mm
Major Components: Radiator, Water Pump, Thermostat, Hoses, Heater Core, Engine.
Question: "My car overheats, what's wrong?"
1. Does your car have a leak? Is it losing coolant? The BEST way to figure this out is to use a pressure tester, or have your car pressure tested. What this does it pressurises your cooling system and allows you to look for a leak. Don't forgett to look in the heater core area (coolant on passenger side floor, or smell of coolant when heater is on, fogged up windows).
If you find your leak, fix it first. If you're loosing coolant and you can't see the leak, you either A. Missed it. or B. It could be leaking internally (headgasket, radiator/trans cooler, etc.)
Please fix your leak first. Running low on coolant will cause the car to overheat, and also introduce air into the system, air pockets can cause overheating, and even cause oveheating while the guage shows correct tempurature, and ALSO not allow your fans to kick on (Coolant sensors and fan switches work off of COOLANT tempuratures, not AIR temps. In other words, if there is an air pocket at 600 degress and it's in the area of a sensor, the sensor doesn't care and recognise it).
Note: Headgaskets USUALLY go between the #2 and #3 Cylinder. If your loosing coolant and don't see it, pull the plugs and especially look at the #2 and #3 cylinders. One clue may be to compare them to the others. If one piston looks Shiny and/or Super Clean. Chances are you have a headgasket issue and the coolant/water is steam cleaning your piston. That's just one check.
Another common symptom of headgasket failure is the immediate pressurizing of the cooling system. If the coolant is FULL and you start the car with the radiator cap OFF, it will shoot out the radiator. If so, it's not good news for your headgasket.
Yet another test is a Carbon Monoxide test. Some SLOW or just starting headgasket leaks can be found with a tester that goes on your radiator, the car is started, and if carbon monoxide is in the system, the liquid will change color, if so, the headgasket is bad and allowing combustion fumes into the cooling system.
Headgaskets don't always rear they're ugly head all the time. Sometimes it's while the car is cooling down it will leak, sometimes under heavy load, etc. It's not always a "as soon as it leaks it keeps leaking" type thing. It can come and go with tempurature change in the engine. But either way, as soon as it starts to go, it needs replaced, it will not get better.
If you replace a headgasket, ALWAYS have a machine shop check it and surface if needed. If you don't have the proper surface, your just causing yourself problems in the future.
2. No leaks, my car still overheats, what's wrong?
A. Does your fan kick on?
1. NO. My fan does not kick on.
The fan on most Honda's kicks on around 190° and off between 182°-188°. Most Domistic cars fans don't kick on till about 224°.
If the fan is NOT coming on and you DON'T have a leak, you need to check Grounds, Relays, Fan, and Coolant Temp Switch, perferably in that order. Check a Honda manual on how to check some of these. There are some simple steps you can do with a multimeter.
2. YES. My fan does kick on.
Ok, so your fan is working, and you you DON'T have a coolant leak. Well it could be a headgasket right? If your not losing coolant then NO, it's not likely a headgasket.
a. A thermostat is a possibility, but haven't seen to many problems in a Honda. If you replace the t-stat (inexpensive) then make sure you get a Honda Part.
Note: Please just put a Honda T-stat in your car and knock that out of the overheating equation. NOT running a T-stat is not a good idea at all. For one, the system was DESIGNED for the t-stat to be there and working properly. Removing the stat on SOME CARS can disrupt the proper flow (not going to get into this right now, but it does happen). Not running a T-stat also causes the Engine Management to run differently. You'll use more gas, and possibly hurt power. Just don't do it.
b. Another possibility is the radiator. But it doesn't leak right? Doesn't matter. A radiator can cause overheating in 3 ways.
1. It leaks (duh )
2. The fins are VERY corroded and missing. Missing fins and a half corroded away radiator does not allow it to cool the coolant properly, and YES, can cause overheating.
2. Blockage. ONE way to check for blockage is a "Infared" Temp Gun. You can check the radiator in several area's and see if there is a major difference.
Now you can STILL have flow, but blockage at the same time. Don't be misled. Partial Blockage can block MUCH of the flow of coolant, but you can still see it "flowing". Years of corrossion and "stop leak" contribute to blockage. If while taking the radiator out you notice it's EXTRA heavy, chances are it has a lot of sediment and should consider replacing. If you do, consider flushing the system well.
c. A water pump usually does not cause overheating (if not leaking) on a Honda. There are some other cars in which the Water Pump "impellers" disinagrate over time, but not usually on Jap. cars. MAJOR sediment gumming up the impellers would be the only case. I'd say darn near unseen on a Honda, but possible.
Cooling System Tips: If your car is coming close to overheating. Turn on your heater, and put the blower on full blast. Your heater core is another small radiator more or less, it can assist in cooling.
If your car goes into the red. PLEASE SHUT THE CAR OFF NOW! Don't drive your car, pull over and shut it off. Why? Because it could be something very simple, but if you keep driving while overheating, you can quickly destroy everything, YES, you can destroy just about everything depending on the extent and temp. Headgasket, head, rings, etc etc etc.
If you really care, use only Honda coolant and parts. Now many backyard hacks on hear don't have a clue, but it has been proven time and again, not just with the cooling system.
Honda Coolant for example has a much less corrosive nature than most other coolants, and last longer. There have been studies that show this. Why do you care? Because less corrossion means less eating away of the gaskets, hoses, radiator, etc. It really does make a difference in the long run.
Use a Honda T-stat as well. Don't cheap out on this.
Last Tips: I see many on HT cheap out and try to "Hack" their way to freedom. I understand some like to keep things cheap, but you usually cause more problems. Do things right, do them once, and it is THEN much easier to solve problems. This goes for the cooling system and many other aspects of the car.
The less you do things properly, the more variables and problems you introduce into the equation.
posted by: juevi
SOME BASIC INFO:
Less than 40% off the heat generated through combustion is turned into Horsepower (this term is called thermal efficency, now this is only applicable to a N/A vechile, if you are F/I this number will change drasticly anywhere from 50% - 200% almost 2x as much).
This means that 60% of the heat occuring from this air fuel mixture is let out through your exhaust and through your cooling system.
Now lets start with the basic components of the cooling system are.
1. Radiator
2. Fan (Electiric / Belt driven)
3. Water Pump
4. Cap
5. Thermostat
6. Hoses
7. Coolant
Now these are all equal in importance, no one is greater then the other.
Now lets check out the basic out the basic functions of these.
Radiator- Exchange the heat into the atmosphere in exchange for cold air. This is called a heat exchanger, Heat exchanger are devices where 2 or more moving fluids streams exhcange temperture. with out mixing.
Fan- The fan is an assistant in moving air toward the radiator accompanied by the fan shroud. Now in most cases the fan is an excessory item the reason I say this becuase most fans do not kick in at highway speeds on in the city becuase air movment is so great at high speeds so in theory you can basicly get rid of your fan at the track for weight saving, but be careful of the temperature and the number of passes you are making.
Water pump- Is like the heart, keeps the circulation with out it you can will die.
Cap- To keep the system under a constant flow the cap keeps the system closed to the atmosphere, and also keep the system under a certian pressure.
Thermostat- A temperture controled valve allowing coolant to pass through to the radiator when hot to allow heat exchange and closed to allow for warm up when cold.
Hoses- Like the vesels keep everything connected.
Coolant- The carrier, that allows for all of this to happen.
When to upgrade radiators?
This question has baffled many of us. The basic guide line is if your vechile is making 10% or less Horsepower then stock and you never really beat on your vechile you really don't need a upgrade. But if your radiator is more then 4 years old and you are generating about 20% more power than stock or do and kind of track/ road racing you should consider and upgrade.
There are so many out there, which radiator to pick?
When choosing a radiator you must understand there are alot of factor that play apart of this process such as core lenght, width, thickness, tube thickness, tube spacing and fin density. Now I can't tell you exactly what to get becuase there isn't a basic guide for this. All I know is companys have spent thousand into research, and have designed certian radiators for certian applications for example a radiator designed for track is going to have a better cooling capacity then a drag. So call the companys and ask. But in general a equal balance of all the properties makes the best radiator.
Now updating fan?
If you are and elecritc fan which most of us are we really don't have any options for update unless there is a double electric fan some where out there that I am un aware of so keep it as it is or find a bigger fan.
Coolant.
For coolant to be able to carry heat it must remain in its' liquid form and not turn into a vapor this is very improtant.
Let us take into conciderator Boilng point. Pure water boils at 100 degrees celcuis
and freezes at 0 degrees celcius, this is all under normal atmposphere conditions. Now if we apply pressure to like 14.7 psi the water will not boil till 121 degrees Celsius, and when you install a 18.9 psi cap water Will not boil till 124 degrees celcuis.
Wait, but pressure is not the only important part of this, mixture is just as important. Ethylene-glycol AKA Antifreeze is a fluid that has chemical additives to prevent rust and to lubricate the water pump. Now using a mixture of water and anti-freeze has its advantages and disadvantages, Using a 33% solution will raise the boiling point 4 degrees celcius, and using a 50% solution will raise the boiling point 9 degrees celcius. But here's the bad Antifreeze does not have the same heat capacity as water it is actually 20% less. So a 50/50 mixture (1 quart) that passes through the system will only be able to carry 80% of the heat, while the pure water can take nearly all away. So this led to the sports world to use pure water and rust inhibitor and boosters that reduce surface tension.
In the bigger picture though when water freezes it increeses almost 9% in volume, and if this where to happen it could cause major harm in cold weather, but here's the saviour again, a 33% mixture will drop the freezing temperture to nearly 16 degrees celcius and a 50/50 mixture will drop the point to almost 37 degrees celcius.
So now I bet you're in a world of wonder of what to fill your car with?
First you must determine the lowest temperture you are going to encounter and then add the least amount of Ethylen-glycol in cordination with this, usally there is a chart for you to fallow on the back as a guideline. But if you are using less then 50/50 mixture please use the additives.
So in the end my friends don't forget to think about the cooling system, If you do be prepared for a multitude of problems.
posted by: q45mm
94' civic si
JDM B16A w/AC
My daily driver: http://tiny.cc/3bdut
K3 GSXR 1000: http://tinyurl.com/3u6obdx
JDM B16A w/AC
My daily driver: http://tiny.cc/3bdut
K3 GSXR 1000: http://tinyurl.com/3u6obdx
