So I am flushing my cooling system tomorrow. I have seen a few post where people drain the radiator, fill with distilled water, run for 15 minutes with heater on and then drain again. Some are doing this maybe 5 times and then adding back coolant. I've never really done a "flush" just drain and fills. I am wondering if I can just either remove the drain plug in the radiator or disconnect the lower radiator hose and pour distilled water into the top of the radiator with the car running and flush it this way. Thought about doing this with the thermostat out so I didn't have to wait on it to open. Thoughts?
Flushing Cooling System...
- Thread starter rewote500
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What kind of car are you doing? When I flushed coolant at home I would take off every hose I could get to. Then run water through every which way until it was clean water. The tricky part then is determining how to get back to 50/50 mix. Some water (sometimes alot of water) would be in the engine.
Originally Posted By: rewote500
So I am flushing my cooling system tomorrow. I have seen a few post where people drain the radiator, fill with distilled water, run for 15 minutes with heater on and then drain again. Some are doing this maybe 5 times and then adding back coolant. I've never really done a "flush" just drain and fills. I am wondering if I can just either remove the drain plug in the radiator or disconnect the lower radiator hose and pour distilled water into the top of the radiator with the car running and flush it this way. Thought about doing this with the thermostat out so I didn't have to wait on it to open. Thoughts?
I generally use the above method (but only 2 or 3 iterations of using distilled water seems to generate clear water draining out for me). Taking the thermostat out (if it's convenient) would certainly save some time.
So I am flushing my cooling system tomorrow. I have seen a few post where people drain the radiator, fill with distilled water, run for 15 minutes with heater on and then drain again. Some are doing this maybe 5 times and then adding back coolant. I've never really done a "flush" just drain and fills. I am wondering if I can just either remove the drain plug in the radiator or disconnect the lower radiator hose and pour distilled water into the top of the radiator with the car running and flush it this way. Thought about doing this with the thermostat out so I didn't have to wait on it to open. Thoughts?
I generally use the above method (but only 2 or 3 iterations of using distilled water seems to generate clear water draining out for me). Taking the thermostat out (if it's convenient) would certainly save some time.
First what car is it and what kind of anti-freeze are you planning on using?
I think it's really a matter of determining what is easiest to access, the block drain, thermostat etc and whether you are going to be using concentrate antifreeze.
Taking the thermostat out then running engine while pouring water in I think would work fine with concentrate. You would need to leave the bottom radiator hoses connected (assuming your T-stat is in the top hose). Either disconnect the top hose from the radiator for the old to come out which I think would be best, or connect the top hose and leave radiator drain open.
You could also just drain the radiator and block and this will get 90%+ and refill with concetrate or premix. As an option you could refill with distilled water run it hot once, then drain radiator and block and then refill with concentrate coolant and distilled water.
I think it's really a matter of determining what is easiest to access, the block drain, thermostat etc and whether you are going to be using concentrate antifreeze.
Taking the thermostat out then running engine while pouring water in I think would work fine with concentrate. You would need to leave the bottom radiator hoses connected (assuming your T-stat is in the top hose). Either disconnect the top hose from the radiator for the old to come out which I think would be best, or connect the top hose and leave radiator drain open.
You could also just drain the radiator and block and this will get 90%+ and refill with concetrate or premix. As an option you could refill with distilled water run it hot once, then drain radiator and block and then refill with concentrate coolant and distilled water.
Kestas
Staff member
Here is how I do a complete flush. Use shortcuts as seemed appropriate.
Coolant Fluid Exchange
1. Drain fluid from radiator and block (if possible)
2. Remove the thermostat
3. Reinstall the t-stat housing and upper radiator hose
4. Disconnect upper radiator hose at radiator
5. Flush system with garden hose through upper radiator hose until water runs clear
6. Disconnect heater hoses, open heat valve
7. Flush heater core
8. Flush overflow tank
9. Run engine for a bit during flushing to get the fluid from the water pump and other dead spaces.
10. Drain as much water as possible from cooling system
11. Run a shorter flush with distilled water to displace the tap water.
12. Siphon water from overflow tank
13. Reinstall thermostat
14. Button everything back up
15. Refill cooling system with specified amount of antifreeze, bring up to level with water, preferably distilled. The amount of antifreeze you need can be calculated from the published cooling capacity for your vehicle.
16. Run car, top off coolant
17. Keep adding water as required every morning until system is topped off.
Coolant Fluid Exchange
1. Drain fluid from radiator and block (if possible)
2. Remove the thermostat
3. Reinstall the t-stat housing and upper radiator hose
4. Disconnect upper radiator hose at radiator
5. Flush system with garden hose through upper radiator hose until water runs clear
6. Disconnect heater hoses, open heat valve
7. Flush heater core
8. Flush overflow tank
9. Run engine for a bit during flushing to get the fluid from the water pump and other dead spaces.
10. Drain as much water as possible from cooling system
11. Run a shorter flush with distilled water to displace the tap water.
12. Siphon water from overflow tank
13. Reinstall thermostat
14. Button everything back up
15. Refill cooling system with specified amount of antifreeze, bring up to level with water, preferably distilled. The amount of antifreeze you need can be calculated from the published cooling capacity for your vehicle.
16. Run car, top off coolant
17. Keep adding water as required every morning until system is topped off.
You're right about the thermostat, if you leave it in doing this five times will take forever because you probably need to drive a few miles to get it to open.
Originally Posted By: rewote500
So I am flushing my cooling system tomorrow. I have seen a few post where people drain the radiator, fill with distilled water, run for 15 minutes with heater on and then drain again. Some are doing this maybe 5 times and then adding back coolant. I've never really done a "flush" just drain and fills. I am wondering if I can just either remove the drain plug in the radiator or disconnect the lower radiator hose and pour distilled water into the top of the radiator with the car running and flush it this way. Thought about doing this with the thermostat out so I didn't have to wait on it to open. Thoughts?
I don't know if you're flushing the Dodge or the Nissan, but the general problem with your idea is that the flush water won't actually flow through the engine. You'll just pour it in the top, and it will take the path of least resistance to the exit- ie through the radiator. If you remove the thermostat, then yes you can (somewhat) accelerate the fill/drain/fill/drain..etc. flushing cycle, but then you're still left with tap water in the lower part of the engine block and you have to guess the right amount of concentrate to add to mix with it (and its TAP water, not distilled).
I'm a big fan of taking the time to (carefully!) remove the block drain plugs and flush a lot of water though there- you'd be amazed how much casting debris sits down in the bottom of the water jackets for the life of a vehicle if its never had the drain plugs pulled. But it is prohibitively difficult on many engines. I go so far as to replace the drain plugs with petcocks so that next time around all I have to do is spin them open to drain the block.
So I am flushing my cooling system tomorrow. I have seen a few post where people drain the radiator, fill with distilled water, run for 15 minutes with heater on and then drain again. Some are doing this maybe 5 times and then adding back coolant. I've never really done a "flush" just drain and fills. I am wondering if I can just either remove the drain plug in the radiator or disconnect the lower radiator hose and pour distilled water into the top of the radiator with the car running and flush it this way. Thought about doing this with the thermostat out so I didn't have to wait on it to open. Thoughts?
I don't know if you're flushing the Dodge or the Nissan, but the general problem with your idea is that the flush water won't actually flow through the engine. You'll just pour it in the top, and it will take the path of least resistance to the exit- ie through the radiator. If you remove the thermostat, then yes you can (somewhat) accelerate the fill/drain/fill/drain..etc. flushing cycle, but then you're still left with tap water in the lower part of the engine block and you have to guess the right amount of concentrate to add to mix with it (and its TAP water, not distilled).
I'm a big fan of taking the time to (carefully!) remove the block drain plugs and flush a lot of water though there- you'd be amazed how much casting debris sits down in the bottom of the water jackets for the life of a vehicle if its never had the drain plugs pulled. But it is prohibitively difficult on many engines. I go so far as to replace the drain plugs with petcocks so that next time around all I have to do is spin them open to drain the block.
i never understood turning the heater on. coolant flows through the core weather the blend door is open or closed...
Kestas
Staff member
That depends on the design of the car. Some cars flow air past both the heater core and evaporator core. It wouldn't do well to run the a/c with hot coolant always circulating through the heater core. Some cars have a switch that blocks coolant flow past the heater core unless heat is called for.
Unless the coolant is really old or you are changing types, why not just drain and fill again?
I just got 7 and 8 year old coolant out of 2 of my cars and changed types. I flushed each with water 4-5 times. Took a whole weekend to do 2 cars between all the heating and cooling.
I just got 7 and 8 year old coolant out of 2 of my cars and changed types. I flushed each with water 4-5 times. Took a whole weekend to do 2 cars between all the heating and cooling.
Originally Posted By: Jakegday
i never understood turning the heater on. coolant flows through the core weather the blend door is open or closed...
What Kestas said and also because if you run air across the heater core it's going to encourage the hot water to enter, heate travels towrds cold.
i never understood turning the heater on. coolant flows through the core weather the blend door is open or closed...
What Kestas said and also because if you run air across the heater core it's going to encourage the hot water to enter, heate travels towrds cold.
I agree with just opening the block drains if they're accessible. If he takes the thermostat out and unhooks the top radiator hose at the radiator and runs the engine while adding distilled water to the radiator he will flush all the old coolant out. Then he'll be left with just distilled water and all he has to do is, after reinstalling the T-stat and radiator hose, add half the capacity in concentrate and top with distilled water.
I'm doing my 1998 Nissan Sentra. I have easy access to just about everything. This car is simple to work on. I have access to all hoses, thermostat, block drain, etc. Going to use full concentrate Prestone. Yeah I know it's a dexclone
but i called around for PGL, almost impossible to find, and nissan coolant was $31 per gallon. I have been using prestone in this car for years with no problem so decided to stick with it.
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If you know where the block drains are and have easy access, then no need for several distilled flushes, which is how I do it now with my Altima. It's simple for you do a couple drains, draining block and radiator (runs clear). I still use distilled water though.
Find your system capacity, fill coolant to min 50% concentration, then top with distilled. Burp it to make sure you've gotten the air out, and put 50% concentration in recovery tank.
$31 is whacked for Nissan, IMO. If you do it every 2-3 years, you'll be ahead of most folks, no matter the coolant.
Find your system capacity, fill coolant to min 50% concentration, then top with distilled. Burp it to make sure you've gotten the air out, and put 50% concentration in recovery tank.
$31 is whacked for Nissan, IMO. If you do it every 2-3 years, you'll be ahead of most folks, no matter the coolant.
Prestone T-Flush is the easiest/fastest way to flush coolant.
http://www.prestone.com/products/flash/accessories/accessories2.swf
I have it on Honda, Lexus ... It took less than 5 minutes to completely flush out the old coolant.
http://www.prestone.com/products/flash/accessories/accessories2.swf
I have it on Honda, Lexus ... It took less than 5 minutes to completely flush out the old coolant.
Originally Posted By: rewote500
I'm doing my 1998 Nissan Sentra. I have easy access to just about everything. This car is simple to work on. I have access to all hoses, thermostat, block drain, etc. Going to use full concentrate Prestone. Yeah I know it's a dexclone
but i called around for PGL, almost impossible to find, and nissan coolant was $31 per gallon. I have been using prestone in this car for years with no problem so decided to stick with it.
Yeah Japanese cars are easy to get to the block drains and in that case best to open the block drain, It'd be almost as easy as the T-flush route.
You might want to change the T-stat as just a precaution. I'd recommend a SuperStant.
Funny thing about late 90's and up Japanese cars is they seem to tolerate Dexcool better than the late 90's GM cars FF with Dexcool do lol. Another interesting thing is if you look at the back of a bottle of Zerex G-05 or Dexcool it recommends for Japanese cars G-05 for '95 and earlier and Dexcool for 96' and later. I don't know if Japanese cars "dexcool proofed" their engines gaskets in '96 anticipation for Dexcool or what. But it intereting that Zerex recommends Dexcool for the '96 up models.
I'm doing my 1998 Nissan Sentra. I have easy access to just about everything. This car is simple to work on. I have access to all hoses, thermostat, block drain, etc. Going to use full concentrate Prestone. Yeah I know it's a dexclone
Yeah Japanese cars are easy to get to the block drains and in that case best to open the block drain, It'd be almost as easy as the T-flush route.
You might want to change the T-stat as just a precaution. I'd recommend a SuperStant.
Funny thing about late 90's and up Japanese cars is they seem to tolerate Dexcool better than the late 90's GM cars FF with Dexcool do lol. Another interesting thing is if you look at the back of a bottle of Zerex G-05 or Dexcool it recommends for Japanese cars G-05 for '95 and earlier and Dexcool for 96' and later. I don't know if Japanese cars "dexcool proofed" their engines gaskets in '96 anticipation for Dexcool or what. But it intereting that Zerex recommends Dexcool for the '96 up models.
Originally Posted By: Jakegday
i never understood turning the heater on. coolant flows through the core weather the blend door is open or closed...
You've never seen a car that has a heater core coolant shut-off valve that only allows coolant to flow when heat is selected? Its less common these days, but they do exist. Lots of 'em.
i never understood turning the heater on. coolant flows through the core weather the blend door is open or closed...
You've never seen a car that has a heater core coolant shut-off valve that only allows coolant to flow when heat is selected? Its less common these days, but they do exist. Lots of 'em.
Originally Posted By: rewote500
Going to use full concentrate Prestone. Yeah I know it's a dexclone
but i called around for PGL,
If it were me, I'd run G-05 in it. Not only do I think its safer than DexClone, you'd be a 1-coolant garage since your Dodge could use it too.
Going to use full concentrate Prestone. Yeah I know it's a dexclone
If it were me, I'd run G-05 in it. Not only do I think its safer than DexClone, you'd be a 1-coolant garage since your Dodge could use it too.
Just button her up. Thanks for all the input. This is the best forum around. Members are willing to give input and offer advice in a timely fashion. Not alot of forums like this. Hats off to all our members and thanks again for the input.
I ended up doing a few distilled water flushes. I'm not the smallest of guys and couldn't quite get to the block drains because the car sits so low.
I'm going to try and get some jack stands before I do the next one and either do a block drain or try the T-Flush.
I ended up doing a few distilled water flushes. I'm not the smallest of guys and couldn't quite get to the block drains because the car sits so low.
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