Hi All,

I haven't been on here for a while since I sold by last Discovery a couple of years ago, but I remember this forum being a wealth of information. Unfortunately, I don't think I found my exact problem via the search function.

I picked up another a few weeks ago ('02 Disco II), and have just started having some issues. The previous owner had just replaced the radiator due to a split tank, but the thermostat didn't look new so I put in a low temp version.

Everything was going great except for a slow leak, which I thought I had narrowed down to the throttle body heater since there was a very small visible leak. I was one day away from changing it out, when all of a sudden the truck started going through a lot more coolant.

I am now having to fill the expansion tank daily, so I've started putting distilled water in since a few days ago until I had time to investigate further. When removing the bleeder screw, I see coolant in the system, which I thought would have run out by now as quickly as I'm having to add water. Am I looking at things wrong? Shouldn't there not be coolant anymore since I've probably put 4 gallons of water in?

Any suggestions on what the problem might be? I'm obviously fearing head gaskets, but I feel like a defective thermostat might be the culprit if it's stuck closed and not letting coolant flow. Temps used to be about 185-188, but now they tend to be at around 195-215 around town. Not terrible, but definitely higher than before.

I'd appreciate any help!

 

If you are constantly filling the coolant it is going somewhere. Either being burned and exhausted or dripping out of the bottom.

No leaks?

Is it rough to start after sitting overnight? That can be coolant in the cylinder/s.

Any misfire codes?

No odd noises in the engine bay?

Can you pull the plugs and see if one looks suspiciously clean? Steam cleaned.

Pull oil cap. Any sludgy looking stuff?

Drop the oil and look for the same.

 

It's not clear whether you're having to refill after you drive the vehicle, or if you have to refill even if the truck is just sitting overnight.
If you have had to add 4 gallons of water in a few days, I'd really expect you to be seeing some symptoms if it was disappearing into the engine, or even directly into the exhaust stream.

Are you sure you just don't have a split in your expansion tank?

 

4 gallons is a lot, are you seeing fluid on the ground? Also check the big tube on the bottom of the expansion tank. That nipple is prone to break off and lose fluid. If your temps are climbing, something is happening, but as others say you would likely see some kind of misfire or symptom

 

Does the coolant smell like coolant or do you have a faint gas smell or oil smell in the coolant jug?

Have you pulled the engine dipstick to make sure you aren't running around with a lovely mocha chino oil/coolant mix? The last time I heard of someone dumping that much coolant into their system over a very short time period when they pulled the dipstick is was actually reading around 10qt due to coolant going directly into the crankcase and mixing with the engine oil...

My Parts truck (an 03 D2) when I got it I was able to crank it and drive it up onto the trailer. When I got home it barely started, but I finally got it to run well enough to move off the trailer it had nearly 11qt of lovely coolant/oil in it. I removed as much coolant as I could, depressurized the system, and changed the oil. The engine is repairable unless the block is cracked, but I'm guessing a bad front timing cover.

It's either leaking internally or externally. Remove the silly engine pan cover to get a really good look under it for coolant leaks. Let us know what you find.

 

I'd be cautious with the water.If it gets low and hot it turns to steam and will blow out your gaskets or hoses.

There is always some coolant lurking unless you completely flush, including the drains on the engine.

The questions above will help you figure it out but that's a massive loss and should be fixed pronto

 

OEM Thermostat or an aftermarket like Motorad/Proline?? Unless you do an inline thermostat stick with the OEM 180F Thermostat.