I have a '98 Disco LSE. I've had my cooling system issues this summer. Wound up replacing the radiator once and the fan clutch TWICE. Since early August, there have been no cooling issues, except the loss of coolant. After I got my truck back from the second clutch repair (first clutch was defective) I noticed the dreaded anti-freeze smell. No leaks, so I naturally thought it was a head gasket leak. But nothing but exhaust smell is coming out the back. My mechanic told me a while ago I had a small head gasket leak, but nothing major. I only lose coolant on long trips when I have the truck over 70 MPH. At speeds over 70, I notice a slight moaning noise under the hood, although I have not been able to identify where it is coming from. If I travel over 100 miles, I will lose a pint or so of anti freeze. Under normal driving conditions, I lose no coolant. There is never any puddles on the ground. The truck starts and runs like a champ. I'm thinking it may be leaking out and burning up on the cats. Anybody have an idea where my mystery leak might be? Any info would be appreciated.

 

I have a 99 with the same issue. It's getting worse and have an appointment with the mechanic for head gasket replacment.

On ours the coolant was dripping out on the drivers side and hitting the CAT and burning off.

 

The best way to confirm that head gaskets are going is to inspect with a flashlight (from under the vehicle) the area behind the exhaust manifolds on each side of the engine---where the cylinder heads mate to the engine block. You will see a seeping of coolant and/or engine oil from that location (sometimes just a couple of drops hanging there). Another place to look ---that is common on the Discovery--- is the throttle body heater plate. This is on the drivers side of the engine-- up top-- under the entry location for the intake plenum. When these leak, the coolant finds its way to the back of the engine and then drips on the exhaust. It is MUCH less expensive to rectify than the head gaskets. And also check the carpeting around the footwell on the passenger side. If it is wet, then the heater core may be the source of your coolant leak. This also sometimes manifests itself as a "film" on the windshield when initially using the defroster on cold mornings. But you would probably smell the coolant if the heater core was leaking badly.

Hope this helps.
Geoman
www.eurotekapg.com

 

Might want to have a shop either do a pressure test on the coolant system or a chemical test that will confirm internal coolant and exhaust mixing.
Mike