Why should I flush my coolant?
24-Oct-2009 | 08:54 PM
#1
Thread Starter
Senior Member
Joined: Sep 2007
Posts: 1,560
From: Pfaff
Why should I flush my coolant?
Cooling System
I’m sure most of you guys have a rough idea of how your cooling system works. Well basically all it does is take heat from your engine, essentially cooling it down. Gasoline is not very efficient.. I believe only 30% of the gasoline burnt is mechanical energy, the rest is converted into heat (why do you think your manifold gets hot as soon as you start it up? On a diesel it takes a few minutes, since diesel fuel is far more efficient). Your cooling system basically works by moving coolant through the engine which collects and picks up heat as it goes by. It then travels through the radiator where air picks up the heat and cools the coolant, this process is called convection. That is a very basic understanding of what your cooling system does.
Why is it important to maintain your cooling system you ask? Well, overtime coolant breaks down and collects rust. This rust and corrosion can cause clogged passage ways in your radiator, hoses, can wear down water pumps and even worse clog a coolant passage in your bottom end. It also can lower the boiling temperature and higher the freezing temperature of the coolant, which obviously can cause your coolant to either freeze or boil. It doesn’t take much overheating to cause a major issue. Infact about 3 minutes of a constant overheat can wreck the headgasket or warp a head/block deck. Not only is an overheat bad, a cooling system is also operating to achieve operating temperature quickly. When your motor is cold (below operating temperature) it causes poor emissions, and increases engine wear because of smaller engine tolerances. That is why driving with no thermostat is so bad for your engine. Another excellent reason to flush your engine coolant is so you do not build up and block passage ways or cause leaks. It can cause a leaking water pump, could produce a weak rad (which can cause an overheat), or even cause a faulty heater core (which is over a 6 hour job on most vehicles). As you can tell, not flushing your coolant regularly can cause an extensive shop bill, it is wise to maintain your cooling system, by checking the level periodically and getting your fluid condition checked by a mechanic, or you can do a rough test by just opening the rad cap (make sure the engine is cold) and check if there is any rust or scaling in the coolant. By doing some preventive maintenance you can save yourself thousands of dollars!
Now, if you want to play around with different variations of coolant, here is some food for thought. Some of you must of heard that race cars use 100% water, so it must be good for your car right? WRONG. I recently got into an argument with a friend because of this. He argued that 100% water is perfectly fine for engine coolant, I corrected him, but he didn’t believe me. Anyways, I’ll now state why 100% water is a poor choice of coolant and why it will cause a cooling failure. Well I’ll start off by saying, water is the most effective type of engine coolant at absorbing heat. That is why it is used on race cars, but race cars are checked out after every race, street cars are not. Coolant that is mixed with anti-freeze has a higher boiling point, lower freezing point and of course prevents rust and corrosion. So if you are driving on a hill and your temperature climbs from 160C to 180 or 190 degrees, what’s going to happen? Well.. the water in your engine might boil and cause a massive overheat (this actually happened to my friends talon). What if you leave your vehicle outside on a chilly September or October morning? The water in your engine might actually ice and freeze! Clearly you can see why this isn't a good idea.
In winter I like to recommend a 70/30 mixture (obviously 70% being anti-freeze) I don’t recommend higher just because any more anti-freeze will probably cause an overheat. Ideally I shoot for a 60-70% mixture, but that’s if the customer is going to want some coolant drained and replaced with water in the springtime (I currently only do this for 2 customers). Usually, I toss a 50/50 mixture in there because that is the safe bet for summer and winter. My recommendation is, if you don’t know what mixture is in your radiator, I think it’s time for a coolant flush. Usually with regular non-longlife anti-freeze, I recommend doing a coolant flush every 2 years or 40-50,000km. This is because at this time interval the anti-freeze actually looses its anti-rust/corrosion properties. Obviously now-a-days you can get longlife anti-freezes that apparently are good for 5 years or 200,000km. Even though these anti-freezes last longer, I still recommend maintaining your cooling system periodically. Just because it says long-life on the bottle, doesn’t mean you shouldn’t check it once in awhile!
Anti-freeze is so cheap these days, $14 for a 4L jug at Canadian tire, that I don’t see why more customers want a coolant flush. It is such a simple job and fairly cheap. Hopefully this article will enlighten some of my fellow enthusiasts to maintain their vehicle and not cause an overheat or a blockage in your system.
HiVelocity Tuning, will now service your cooling system before winter hits!
We will have a limited time special of $80 for a routine coolant flush (includes coolant) and an engine compartment check-over!
E-mail myself or zeeman today to book your appt!
I’m sure most of you guys have a rough idea of how your cooling system works. Well basically all it does is take heat from your engine, essentially cooling it down. Gasoline is not very efficient.. I believe only 30% of the gasoline burnt is mechanical energy, the rest is converted into heat (why do you think your manifold gets hot as soon as you start it up? On a diesel it takes a few minutes, since diesel fuel is far more efficient). Your cooling system basically works by moving coolant through the engine which collects and picks up heat as it goes by. It then travels through the radiator where air picks up the heat and cools the coolant, this process is called convection. That is a very basic understanding of what your cooling system does.
Why is it important to maintain your cooling system you ask? Well, overtime coolant breaks down and collects rust. This rust and corrosion can cause clogged passage ways in your radiator, hoses, can wear down water pumps and even worse clog a coolant passage in your bottom end. It also can lower the boiling temperature and higher the freezing temperature of the coolant, which obviously can cause your coolant to either freeze or boil. It doesn’t take much overheating to cause a major issue. Infact about 3 minutes of a constant overheat can wreck the headgasket or warp a head/block deck. Not only is an overheat bad, a cooling system is also operating to achieve operating temperature quickly. When your motor is cold (below operating temperature) it causes poor emissions, and increases engine wear because of smaller engine tolerances. That is why driving with no thermostat is so bad for your engine. Another excellent reason to flush your engine coolant is so you do not build up and block passage ways or cause leaks. It can cause a leaking water pump, could produce a weak rad (which can cause an overheat), or even cause a faulty heater core (which is over a 6 hour job on most vehicles). As you can tell, not flushing your coolant regularly can cause an extensive shop bill, it is wise to maintain your cooling system, by checking the level periodically and getting your fluid condition checked by a mechanic, or you can do a rough test by just opening the rad cap (make sure the engine is cold) and check if there is any rust or scaling in the coolant. By doing some preventive maintenance you can save yourself thousands of dollars!
Now, if you want to play around with different variations of coolant, here is some food for thought. Some of you must of heard that race cars use 100% water, so it must be good for your car right? WRONG. I recently got into an argument with a friend because of this. He argued that 100% water is perfectly fine for engine coolant, I corrected him, but he didn’t believe me. Anyways, I’ll now state why 100% water is a poor choice of coolant and why it will cause a cooling failure. Well I’ll start off by saying, water is the most effective type of engine coolant at absorbing heat. That is why it is used on race cars, but race cars are checked out after every race, street cars are not. Coolant that is mixed with anti-freeze has a higher boiling point, lower freezing point and of course prevents rust and corrosion. So if you are driving on a hill and your temperature climbs from 160C to 180 or 190 degrees, what’s going to happen? Well.. the water in your engine might boil and cause a massive overheat (this actually happened to my friends talon). What if you leave your vehicle outside on a chilly September or October morning? The water in your engine might actually ice and freeze! Clearly you can see why this isn't a good idea.
In winter I like to recommend a 70/30 mixture (obviously 70% being anti-freeze) I don’t recommend higher just because any more anti-freeze will probably cause an overheat. Ideally I shoot for a 60-70% mixture, but that’s if the customer is going to want some coolant drained and replaced with water in the springtime (I currently only do this for 2 customers). Usually, I toss a 50/50 mixture in there because that is the safe bet for summer and winter. My recommendation is, if you don’t know what mixture is in your radiator, I think it’s time for a coolant flush. Usually with regular non-longlife anti-freeze, I recommend doing a coolant flush every 2 years or 40-50,000km. This is because at this time interval the anti-freeze actually looses its anti-rust/corrosion properties. Obviously now-a-days you can get longlife anti-freezes that apparently are good for 5 years or 200,000km. Even though these anti-freezes last longer, I still recommend maintaining your cooling system periodically. Just because it says long-life on the bottle, doesn’t mean you shouldn’t check it once in awhile!
Anti-freeze is so cheap these days, $14 for a 4L jug at Canadian tire, that I don’t see why more customers want a coolant flush. It is such a simple job and fairly cheap. Hopefully this article will enlighten some of my fellow enthusiasts to maintain their vehicle and not cause an overheat or a blockage in your system.
HiVelocity Tuning, will now service your cooling system before winter hits!
We will have a limited time special of $80 for a routine coolant flush (includes coolant) and an engine compartment check-over!
E-mail myself or zeeman today to book your appt!
Last edited by chris_v2; 25-Oct-2009 at 03:55 PM.
25-Oct-2009 | 07:00 AM
#4
Senior Member
Joined: Oct 2007
Posts: 734
From: Burlington
Good write up buddy, I think this is definitely something a lot of people overlook. I've considered doing this at home with the garden hose method, but didn't want to run coolant into the sewer system, how do you guys do it?
25-Oct-2009 | 10:01 AM
#5
Thread Starter
Senior Member
Joined: Sep 2007
Posts: 1,560
From: Pfaff
If there is no access to a coolant machine, I always recommend draining the radiator first, then draining the engine block plug as well. This will get about 70-80% of the coolant out of the system.
If the coolant hasn't been flushed in a while and I want to get all of it out, I will just undo both heater core hoses and run a low pressure hose through the system and feed the 'drain' hose into a bucket to ensure I catch all the coolant coming out.
If the coolant hasn't been flushed in a while and I want to get all of it out, I will just undo both heater core hoses and run a low pressure hose through the system and feed the 'drain' hose into a bucket to ensure I catch all the coolant coming out.
25-Oct-2009 | 07:55 PM
#7
One reason race cars use water only is because if you have a leak/blow out at the track its only water left on the track instead of slippery coolant so its less time consuming to clean.
Most track cars are only run for minutes at a time and have rediculous radiators
Most track cars are only run for minutes at a time and have rediculous radiators
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