It's going through about a pint of coolant every couple of weeks. Not getting white exhaust, or sweet smell to the exhaust. Just a scent of burnt coolant around the engine when warm.

I've gone through the pressure test - held at 17lbs for over 20 minutes. I didn't notice any leaks as I was looking around.

Last time I used the block tester, there was no sign of exhaust in the coolant.

It's running great, no mis-fire, no stutter, no issues other than the coolant loss.

Today, after letting the Disco clear a path through the 2 feet + of snow in the driveway, I noticed some drips of coolant in the snow where the Disco drove. So I at least I know there's a leak.

I'm holding out hope it's not the HG, but can't for the life of me figure out where else to look. Dealer wants just north of $3k for the HG work, and I can't find any shop locally in southern NH who's willing to work on the Disco.

Any other thoughts on how to track down this leak?

 

One possibility could be coolant exiting the expansion tank and "burning off on the exhaust manifold. When parked where do you notice the coolant on the ground in relation to truck? You could pick up a UV dye test kit to check the rest of the system. might be a good idea to try bleeding your system a few times. If you have air pockets your going to run hotter and loose coolant via overflow. Do you have an aftermarket temp reader / "Ultra Gauge"?

 

Meh, prolly just a fuse.
Mentioned above, uv dye. Then make sure to look at the back of the heads. Likely if it's hg, that's where you'll find it

 

Could the Expansion Tank Cap have anything to do with this? If you've never replaced it try it. It needs done anyways.

 

Also the number one source of coolant leaks is the Throttlebody Heater Plate. Its loacted on the bottom of the Throttlebody. If you follow the coolant line from the bottom of your expansion tank it will lead you to it. You can replace it easily if you want, or some of us just leave the defective one in place and delete it from the cooling loop by bypassing it completely. All you need to do this option is a brass coupling with 2 male ends and some new hose clamps. It was the source of my slow leak. I spoted coolant on the driver side valve cover and and sterring rod. It wouldn't leak while I was under the under the hood looking for the leak, but only while driving. I guess it builds more heat and pressure while driving. I bought a replacement, but finally opted to just bypass it because the Risk vs. Reward ratio of it being in the cooling loop sucked in my case. I live in Alabama and it just doesn't get cold enough here to need it at all. I would definitely mention the bypass to a buyer if I were to ever sell my Disco, but come on... What kinda man sells his Disco?

 

Throttle body plate was taken care of last fall, and was leaking - so at least that's taken care of. But once it warms up a bit here I'll give the dye at try and hopefully track it down.

Good thought on the expansion tank cap, cheap and easy enough to try anyway.

But with another FOOT of snow expected tomorrow, I'll just top off the coolant and drive it for now.

 

I did that for awhile. I could always tell when I needed to add water because the Heater would start sucking. Lol!

 

When the snow lets up, lay underneath it with a flashlight and check the front and back of each head. You'll likely see an area where a tiny coolant leak has dried underneath the head. These head gaskets tend to fail in such a way that the only symptom is coolant smell and a slow leak. Pressure testing might show a tiny leak if you lay underneath it with a light.

Mine was blown similarly when I got my truck, on the front driver's side. I've just closely watched it and kept driving for almost 3 years and 20k miles. The leak has stayed the same, though the barrs leaks tablets stop it for about a year and then have to be reapplied.

I'm definitely rolling the dice that it could fail anytime, but at this point I'm curious to see how long it lasts. And I just finished a 2000 mile road trip with no issues.

 

What happened with the leak? Worthless thread started. 1 of thousands