I'm a new '03 Disco II SE owner who is anxious to get routine maintenance items resolved so I can get on the snowy roads here in PA. We just got 8" of powder and the Rover is sitting in the garage - not very happy about this.

I'm thinking the PO had some stop-leak in the radiator because when I drained the coolant to refresh the system with new 50/50 Dex-Cool I got a pretty serious leak from the heater core. The sense I get from reading through many, many, many posts on this subject is that the cores rarely fail but it is the o-ring seals to the heater core pipes that go bad.

So my questions are (1) Should I be prepared for an 11 year old heater core to have failed?, and (2) How difficult is it to replace the o-rings and heater core pipes with the dashboard in place?

Thanks in advance for advice from members who have been through this.

(BTW, seems there should be a write-up on this heater core o-ring replacement procedure in the prevailing Stickys but I'll be damned if I can find it. If someone knows of such information for the Disco II please provide a link in this thread - thanks.)

 

1st drain the Dex-Cool and use regular Antifreeze and distilled water at 50/50. Or use the pre-mixed.

Have you determined 100% that it is Antifreeze that is leaking? Is it sticky oily feeling?

Take a look at this post for ideas of a short cut in case it is the Heater Matrix.
https://landroverforums.com/forum/di...acement-21963/

 

Okay thanks for the link I'll have a look. Yeah, unfortunately the passenger side carpet is wet with coolant and it leaked out through the floor onto the ground. Bitter taste, definitely coolant.

I'm a Dex-Cool guy...

The owner's manual says stick with it -- have you experienced trouble with the extended service coolant? I thought unless you had one of the BMW engines Dex was the way to go on Land Rovers.

 

Dex-Cool is horrible in these engines. Just do a search on this forum for Dex-cool and see.

 

Okay, I'm in no position to disagree with anyone here being so new to the Disco experience. It will be Prestone and distilled water on the re-fill then.

 

Ditto on using regular old coolant - I swapped mine about 3 years ago and the cooling system has been working great *knocks on wood*.

As others have said, there are many studies, pictures, and even dedicated websites showing what dex cool can do to certain systems and engines. I think it was hastily adopted by land rover at the time, before most of this research was done (kinda like the entire bypass-based cooling system itself! - which they also no longer use lol!)

I don't think an all-out failure is that common though, how many miles are on yours?

 

Which Prestone? There is Prestone Dex-cool, Extended life (another organic acid based coolant), and the old green stuff.

 

It's a garage-kept beauty with 137.5K miles, probably all asphalt.

 

Yeah, I meant the old green stuff. It's been really cold so I haven't done the work yet -- can a person still buy glycol-based (old green stuff) coolant?

 

If you want to get it on the road, just disconnect the two hoses on the core in the engine bay, cap the core off, and throw a hose connector between the two any bypass it in the meantime so you can get around on the sloppy roads for now, just keep an eye on the temps, not sure what % cooling capacity the core actually adds but if your thermo and fans are working correctly shoudlnt be an issue.