I have a 99 Disco II with 160K miles on it. It's been running fine until yesterday. I drove it about 300 miles straight this past Sunday with no problems.

Then yesterday (Monday), I went on a short trip (about 1/2 mile) to the store. When I parked, I noticed coolant leaking out of the front on the drivers side...seemingly under the radiator as far as I could tell. I had not even driven far enough to reach normal temp.

I went straight home after the store and didn't drive it again yesterday.

This morning, I checked the overflow and it was empty.

I removed the plastic splash guards (I think thats what they were) under the radiator to see if I could find the leak.

I didn't have coolant on hand so I put about 1/2 gallon of water in and started it up...

No leaking..but after about 10 minutes of running, the overflow tank started to boil. I watched it come out of the hose...it was water at first and then the coolant started coming out.

Dash temp was still normal. I let it run for another 10-15 minutes, and the dash temp finally started to rise.

Turned the heat on...nothing but cold air. The heat worked on Sunday.

There was only a small amount of coolant leaking from the radiator on the drivers side this time. Most of it was bubbling out of the overflow. Including out of the cap. CORRECTION: I couldn't see the radiator so I still don't know where is was leaking from..I'm assuming a lower radiator hose??

I didn't let the temp get to the red...I shut it off before it could get that high.

So I'm thinking my thermostat quit working...or perhaps I have a clogged radiator?? Help? Need to know where to start!

 

Pressure test the cooling system.
Either your thermostat is bad, a blown head gasket or a clogged radiator.

 

Thanks. I don't have a pressure tester and haven't ever used one. I'm pretty mechanical, and have access to a shop with lifts...would it make more sense to buy one (around $70 at Harbor Freight) or take it somewhere?

 

You can rent them, the only problem you might run into is it may not fit your truck.

But if you can get one that does fit then doing a pressure test is easy.

With the engine cold and off put the tester on in place of your radiator cap, pump it up (its like a bike pump) to 15psi.
It should hold there for at least a hour.
While it is holding pressure you can look for leaks.
If it looses pressure fast the leak should be easy to find.
If you rinse the engine with water first the coolant will be easier to see where it is leaking from.

 

I'm not sure there is a cap on my radiator (at least I can't see one)...

Would I use the overflow tank instead?

 

Yes, sorry, the overflow is part of the cooling system and that is actually your radiator cap.
The overflow tank is also pressurized.

 

My newest Rover friend has a nice 2000 DII. He says he can hear water gurgling in the dash, any ideas?

 

Low on coolant.
He has air in the system, top it off and if it happens again have it checked for leaks.

 

Ok...so I rented a pressure tester from autozone. Of course, it didn't fit.

But...after reading some I realized that the overheating was probably caused by not bleeding the system after I added coolant.

So I followed the instructions for bleeding and filled it back up. Let it run for about 30 minutes and it didn't get hot...thankfully. Oh..and the heat worked again.

No leaking either. So I ran some errands and all was fine until I had been out (stop and go) for about 3 hours. I had driven about 40 miles total.

Coolant started leaking from that same front side! I still can't see where it's coming from...but it's so far in the front & to the left (drivers side) that its dripping from the front corner of the bumper. No overheating at all..just the leak.

This morning...I topped it off & bled the system again. This time it started to leak immediately. I hadn't even turned the truck on. Every other time I added coolant the leak didn't appear until I had been driving for hours.

Now the leak is constant and by the time I got home today, the truck started to get hot. Luckily that didn't happen until I was 1/2 a mile from home so it never got to the "red".

Obviously, the overheating happened because most of the coolant had leaked out by the time I got home.

Confused...I'm hoping this could just be a hose?? Is there a lower hose on the drivers side of the radiator?? I can't even see the radiator!

Also, does anyone know a Rover mechanic who can pressure test the cooling system in Michigan? Detroit area? Or at least where I can get an adapter for the one at autozone.

 

If its leaking onto the front bumper it is probably a bad radiator.
You are going to have to start poking around, take a flash light and get dirty.