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What is the most effective way to flush coolant?

19K views 11 replies 7 participants last post by  intender 
#1 ·
I checked YouTube and there were some good ones, but not Xterra specific. Some even installed hose attachments to connect a garden hose and flush the system.

From what I've read, is this correct?

1. Drain radiator

2. Fill with Prestone FLUSH

3. Run car for 15mins with cap off to BURP system. Turn on heat full blast.

4. Drain again

5. Full with 50/50 water/coolant

6. Run car again for 15mins with heat on

7. Drain again.

8. Refill with ZEREX Asian Vehicle coolant

9. Done

Yes/no?
 
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#2 ·
Environmental Assualt by Coolant Rinsing



In short, no....that is a waste of time and an abundance of waste generation for a low risk issue related to old fluid.

Drain old, there isn't 1% of old fluid remaining pooled in the system.
Fill with water, circulate for a couple minutes DO NOT ALLOW TO HEAT UP with straight water.
Drain...there isn't 1/1000 of original coolant remaining and it is biologically harmless at this stage.

Fill with proper 50/50 mix and away you go.
 
#3 ·
In short, no....that is a waste of time and an abundance of waste generation for a low risk issue related to old fluid.

Drain old, there isn't 1% of old fluid remaining pooled in the system.
Fill with water, circulate for a couple minutes DO NOT ALLOW TO HEAT UP with straight water.
Drain...there isn't 1/1000 of original coolant remaining and it is biologically harmless at this stage.

Fill with proper 50/50 mix and away you go.
Thanks for that.

Of course after I ask such a question, my car decides to puke coolant all over the engine.

It shouldn't be the pump, it's less than a year old. My car was also still running and moving when I overheated.

There was a large amount of steam coming from the stem below the the radiator cap.

I don't know if that's a pressure release area or if the plastic stem of the radiator cracked.

The fluid is all over the top of the engine. Like I stood in front of the car and just sprayed it with a hose.

I would think if a head gasket failed, that the fluid would just pour out.

Any thoughts on this?

Thanks
 
#4 ·
Radiator Leak / Engine Coolant Steam Bath

There was a large amount of steam coming from the stem below the the radiator cap.

I don't know if that's a pressure release area or if the plastic stem of the radiator cracked.

The fluid is all over the top of the engine. Like I stood in front of the car and just sprayed it with a hose.

I would think if a head gasket failed, that the fluid would just pour out.

Any thoughts on this?

Thanks
First, wait for engine to cool down then rinse entire engine bay to get the coolant off all the rubberized items. DO NOT RINSE A HOT ENGINE

Let dry before you try to crank !!! If you have a leaf blower, you can push the water out of the accumulation points. I think the spark plug wells are a shallow area which can be a problem for wash downs.


Your leak could be one of a few things.....

You should have a hose from just below the radiator cap down/over to the expansion tank. If the hose is loose, it will vent steam instead of fluid back to tank.


If the radiator has a crack in the area around the cap, which is common, you will need to replace the radiator. $130 max and about hour of time. very easy.


OR, look carefully, could it be one of the upper radiator hoses connecting near the cap ?

My hose rupture was the bypass hose left and below distributor. steam / fluid was everywhere and it took a while to find the source until after I refilled radiator with coolant mix.
 
#5 ·
So the latest is it's a cracked radiator. Thankfully that's all it is. I feared the worst, that it was a valve gasket.

My brother did a pressure tesT to determine It was the radiator. So he ordered me a new radiator and cap. I believe there's a NAPA location near me to pick up some ZEREX asian formula coolant.
 
#6 ·
In short, no....that is a waste of time and an abundance of waste generation for a low risk issue related to old fluid.

Drain old, there isn't 1% of old fluid remaining pooled in the system.
Fill with water, circulate for a couple minutes DO NOT ALLOW TO HEAT UP with straight water.
Drain...there isn't 1/1000 of original coolant remaining and it is biologically harmless at this stage.

Fill with proper 50/50 mix and away you go.
I checked mine today. My anti freeze is really clean, but was only good to 10 degrees. I wanted to drain a gallon out, and add straight anti freeae, instead of 50/50. Where is the drain plug on these rads? I looked forever, I could not find it?
2000 Xterra 3.3/Auto

.
 
#7 ·
I checked mine today. My anti freeze is really clean, but was only good to 10 degrees. I wanted to drain a gallon out, and add straight anti freeae, instead of 50/50. Where is the drain plug on these rads? I looked forever, I could not find it?
2000 Xterra 3.3/Auto

.
Bottom of the radiator, slightly off center towards the drivers side. May be a rubber skirt you have to remove to find it. Drain looks like this.

 
#12 · (Edited)
In short, no....that is a waste of time and an abundance of waste generation for a low risk issue related to old fluid.

Drain old, there isn't 1% of old fluid remaining pooled in the system.
Fill with water, circulate for a couple minutes DO NOT ALLOW TO HEAT UP with straight water.
Drain...there isn't 1/1000 of original coolant remaining and it is biologically harmless at this stage.

Fill with proper 50/50 mix and away you go.
actually I would greatly disagree with what you said. The cooling system on the xterra holds 11 5/8 quarts of coolant. Thats almost 3 gallons of coolant. Unless you pull the plugs on the engine block you are not going to get anywhere near that much out of the system. And most people arent going to go through the trouble of pulling the 2 block plugs to drain it completely. You will be doing good to get half the coolant out of the system by draining the radiator. So after a drain and fill and another drain you are still going to be looking at an absolute best case scenario of 20-25% of the coolant left in your system that is still sitting 50% full of fluid. That is assuming the car ran long enough to mix the water and remaining fluid well.

Does this mean you need to continue to fill and flush to get it all out? I would say no, but if you really want to get the system clean and get a proper level of coolant put back in the car you really need more than a 50/50 mix after a single flush. One flush would leave you with 20% mix in half the system and 50% mix in the other half. So again best case scenario you end up with about 35% concentration of coolant in the system. what I do is drain the radiator twice, fill with 50/50 after the first drain let it run for a bit and drain the system again and fill with 50/50. and then after about 2 weeks I drain again and refill with 50/50. Is it overkill, possibly, but I am also the kind of guy that uses distilled water for flushing the system. never understood buying high dollar coolant that is vehicle specific to stop corrosion and then using a water hose to flush your system.
 
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