To start off, I would like to say that I am new to this forum. (Hopefully I posted this correctly)
I am seeking help/advice about what I can do to help a family member that is having Issues with their 04 Disco II.

I have some, but limited mechanical knowledge, I could probably do most things if I have proper instructions.
Here are the symptoms:
It began when the car started to overheat while idling in a pickup line. The red light came on on the temperature gauge, and it was slightly above 1/2 way up the gauge. From my research on this forum, It seems that is around 220 C. (I know, that's very hot)
Wet passenger carpet, and occasionally the rear passenger side carpet.
When I checked the coolant 2hrs after parking the car, it had almost none. Like less than a 1/4 full. (Coolant Expansion Tank)
After this incident I filled the reservoir with bottled water. I know I know, It isn't the best thing to do, but I did not have any dexcool available. It was NOT tap water.
Then, it drained out again and the passenger carpet was even wetter. (Although the carpet does not smell sweet like coolant)

The A/C drains were completely clogged on both sides, so after a little bit of wrangling my arm up around the (transfer case)?, I used a pick to clean out the A/C drains, and the drains work fine now.

After this I went to the local supermarket to buy distilled water.
I then proceeded to use distilled water to refill the reservoir 3 different times. 1 time it had 1/4 left, another 1/2, and the last time it had like 2/3 left.
The A/C is colder on the drivers side than the passenger side when maxed out. I read this similar thread: Driver Side Cold Passenger Side Not as Cold

After this, it didn't loose any coolant until the rear A/C was turned on the next day.
When the rear A/C was tuned on, the car tended to loose coolant when I checked the level at night. Like between 2/3 and 3/4 full. My question is, is it burning the coolant off or do I have a bad heater core?
I understand that this is confusing, but to be clear it was loosing coolant and the A/C was not draining.
I would also like to know if it makes sense to flush to coolant system with distilled water and replace the dexcool orange/red with standard Prestone pre-dilluted.
Note: the truck is stock with the exception of larger tires.
Any help is appreciated.
Thanks.

 

220 F, if it was 220 C things would melt down. Literally.

The coolant on the floor board is a leaking heater core. Will have to replace the unit. Kinda of a pain. Water wont hurt it in the short run. The dex cool is crappier than water IMO.

Running that hot might have caused a slight head gasket leak which is fairly common. You'll want to do more reading about a cooler thermostat, fans etc. The rear AC will only make the compressor run under the hood, which makes the truck run hotter.

You most likely have a heater core leak, possibly more. You got pretty hot but might have gotten lucky? Pressure tester on the coolant system is your friend. You probably have air in the coolant, which needs to be bled after you fic the leaks.

 

Thanks for the reply.

I also realized the mistake I made... 220 F is correct

I will try to bleed to cooling system and see how that goes.

Is a cooler thermostat one that opens at a lower temperature?

To solve the wet floorboards, is it ok to bypass the heater core with a U shaped hose?

I bought prestone pre-diluted non-dexcool, Is this better than Dexcool? From what I have read here people seem to be saying that dexcool is terrible.

 

@RoveronLand Dexcool was a real problem a number of years ago it affected and attacked certain gasket materials, but you are better off replacing it if you need to flush anyway then you do not have to worry about it.

 

Thanks for your reply, I want to replace it but might not have time to do it for a while.

 

It is ok to by pass the heater core. I did that for awhile before I fixed mine.

The wet passenger rear floor is all draining down from the front. Nothing to do with the rear a/c there.

The heater core might not need replacement. The hoses that attach to it could be old and letting coolant spray through the firewall. I've seen this happen.

If you are that lucky, you would need to clean the existing inlets with a brass brush and brake clean or similar, and then replace the hoses with new OEM ones.

Also, if this was your truck, and you lived in the south, I would suggest doing the in-line thermostat mode and throttle body bypass.
Not sure how involved you want to get ?

 

Yea it's also worth thinking about pressure testing. Like COSitsWORTHit said, it may not be the core itself. I'd inspect the hoses and if they need replaced, go ahead and replace them and then pressure test.

 

Pressure testing is something that I certainly plan to do the next time I am down by the car, which I won't be for a many months, as it is not mine. When I am there next, I do plan on flushing the coolant and replacing it with the Prestone green kind, not sure which one exactly.
I will also check the hoses when the engine has run for a while.


Note I: I did notice a very small puddle of coolant on the top of the valve cover, but the pool never seemed to get larger, and was filled with older, crusty coolant. I also did not notice any leaking coolant hoses.
Note II: The heater core blows very hot air.
As someone asked, the car is in Florida, and I am not usually in Florida.
I will have to look into lower temp thermostats, or removing it completely if possible. I have also read about the throttle body bypass, but I'm not sure of its benefits.