How to flush cooling system?

[anthonygubbin]

I wouldn't try and undo any drain plugs on the block. If they are anything like the 4.0 it will surely be seized and you could end up damaging something trying to get it undone.

Regards A

[anthonygubbin]

Originally Posted by Isaiah53

Anyone know what the approximate capacity for the water is? Just wanting to make sure I get the coolant/water ratio right.

Assuming Nulon green is ok just tip in 95% of the 5L concentrate bottle and fill the rest up with demineralised water. Keep the 5% concentrate for the overflow bottle. Nulon green is as concentrated as it gets, 5L will be plenty.

Regards A

[xjeepping]

On the petrol engine, there are two drain bungs on the block below the exhaust manifiold. I just changed the coolant in my radiator after seeing some brown color under the radiator cap. Old coolant came out light green but replaced it anyway. The little plastic radiator drain plug at the lower RH side (left from the front) is a bugger to access as it sits close to the headlight bucket in the front apron. Accessed after removing the front grill.

[..dylan..]

That's what I call an answer, thank you so much!

[layback40]

Originally Posted by Isaiah53

Anyone know what the approximate capacity for the water is? Just wanting to make sure I get the coolant/water ratio right.

Do you have an owners manual? ~ the book in the plastic pouch in the glove box. It gives all fluid capacities & plenty of other useful information.

[Roler]

It's somewhere around 11.2 ltrs in the 4.0, IIRC
Total, not the water part.
Make it 50-50 mix, or at least 33% coolant (I went from 50-50 towards 33% by having to add distilled water due to radiator leaking coolant slowly....actually brought my temp down over time)

[vernicious]

I need to do the same to my to my VM. I've been doing some reading on how to properly cleanse the entire system. My XJ is caked up pretty good. There are several thoughts on how to cleanse. I've seen people talk about using powdered dish washing detergent and other home remedies. I'm considering trying that as a first step.

Has anyone used CLR to clean the system? I've considered using it, but I'm concerned about the pump seals etc. (For the record once I found out that my #3 head was cracked I used CLR to see if it would clean the channels, and had zero issues with it eating the metal.)

So the question is, what have you used to get gunk out of the cooling system? My heater doesn't work as well as it should, and I already cracked one head due to faulty coolant flow...

And go!