I bought a 2004 Discovery with 75k and started driving it back home. Traveled about 90 miles and stopped for fuel. Getting back on the road as i accelerated onto the interstate the temp started to rise. Pulled off and found the coolant level low. Replaced about half gallon and drove another 200 miles on the interstate without trouble. Stopped for the night and replaced about 1/2 gal in the morning before heading home. Traveled another 200 miles before siting in traffic just off the interstate and had another temp rise and a need for another half gallon of coolant. I see no exterior leaks. Bought a replacement thermostat hoping that is the problem but where is the coolant going? So i suppose I am burning it off thru a leak in the head gasket? Haven't replace the thermo yet and also have Blue Devil Head gaskets fluid to try. I am not a real mechanic and am afraid to do anything without experienced advice. HELP!

 

Pull the dipstick, if it's getting in the oil it will show there as a chocolate milk shake colour. Go from there. Also, double check it isn't leaking out the back of the heads onto the transfer then hitting the exhaust pipe.

 

If you can't see a leak, sounds like the head gaskets. I had a similar problem last year and that turned out to be the throttle body heater plate gasket. It will drip all over your driver side valve cover.

 

certainly sound like a head gasket

 

Go to autozone and get the head gasket/block tester. Basically the fluid changes colors when exposed to CO2 in the coolant reservoir. That will tell you if you have a hidden head gasket leak/ block leak or a leak somewhere in your hose. In which case you might look into getting a pressure tester. Tough to find one to find Disco reservoirs though. Good luck!

 

Before major repair is taken on answer these questions first:
These are the list of things that can cause an overheat without losing fluid
1. Thermostat sticks or does not work
2. TRASH in front of radiator
3. Crap (stop leak among other things) has some of the radiator blocked up.
4. Water pump not operating at 100% due to worm parts (impeller)
I have had all of the above happen on one of mine so it is common.

 

You just bought it and it's leaking 1/2 gal every 200 miles? Is returning it a possibility? or you got a good deal? I hope it gets sorted out soon

 

do you have a more precise gauge to measure the temp? such as an ultragauge? to find out exactly how hot your D2 is getting, and what temp it is when not overheating?

 

Is there white smoke coming out of the exhaust? If there is, that is definitely a head gasket leak or even an engine block leak. Get it pressure tested. Or check the compression of the cylinders yourself. If you have low compression, that would also indicate a head gasket leak.