Guitarz32388
1. Check your belt tension.
2. Check your radiator fan clutch (with the engine off). Make sure it is not free wheeling. The
fan should offer some resistance when your trying to spin it. The reason I say this is because you say that the engine temp goes down when the truck is moving (eg. generating more heat than idling) except that air is rushing past the radiator by ram action also.
3. If the fan clutch is ok, I would do a chemical flush (acid/base type) of the radiator and try to clear out the passages which may be clogged. Don't be over zealous in leaving the radiator flush too long since it is corrosive. It can do a job on your water pump seal.
4. Regarding Dexcool there's alot of controversy regarding that coolant. GM has had some issues with it regard
head gasket problems. IMHO it has a protective effect on the water pump impeller (from cavitation corrosion) in the LR.
LR suggest changing it every 3 years.

Ed

 

I had a problem with my A/C condensor fans.. You might want to check those out..The symptoms were the same but if my engine started to get hot I put it in neutral and put the Idle up and that would cool it down. I replaced the fans and havn't had a problem since.. I have a 98 disco.

 

Good idea.

 

I had an overheating problem literaly the day after I bought my 96 Disco SE7. After I replaced the thermo it still overheated. So, I removed the rad to have it flushed professionally and tested for leaks. What I found was the entire radiator ROTTED!!! You know how you can run your fingers over the flukes of a radiator and they'll bend slightly under the pressure? Well in this rad the flukes would just FLAKE off in your hand! An entire section the size of my fist had already been knocked off from riding around I presume. I'm not sure what caused such a massive corrosive breakdown, but I ended up replacing the unit. I got a good price for a used rad off line.

I flushed the system using a heater hose tap that I bought froma local parts store. Following the instructions was pretty easy. I filled it with Dexcool per some suggestions on this forum and have monitered the system regularly. My temp hasn't risen past the half way point on the gauge even with the AC running wide open and me and three buddies riding down I-20 from Augusta to Atlanta (150miles+Maybe?) in the absolute crazy Georgia heat!

 

You have to open the bottom hose and let it all drain out. re-connect the hose,fill with water through the bleed screw on top of the radiator and start you engine. With the heater going on full hot, full blast, let it warm up to operating temp and fill through the bleeder screw. Once you level is good, let it run a few minutes. Shut it off, let it cool, drain and repeat. I did this 8 times because of concerns about switching to Dexcool, and using the chemical flush. probably overkill, but I know there wasn't any bad stuff still in there. The heater hose tap sounds like a good idea, but I have never used one. I just like wasting my weekends on pointless tasks to make myself feel better.....
hope this helps

 

Hey guys just wanted to let you know I got my radiator cleaned. Apparently it was only like 20% effective. I drove it home a good half hour today which has been the hottest day this summer think with the AC on and my car didnt overheat. I have to drive tomorrow and the next day hopefully i wont have any problems. Thanks to everyone who helped. Now 've got to go start a new topic.

 

Well I called that one![sm=icon_rock.gif]

 

Which model did you go with, the aluminum or copper/brass? Which is more efficient, and which would last longer?

 

No, the right way is to open the block plugs and drain the block directly, you don't need to remove any hoses at all. The right one is a bit of a pain though, the left is obvious but the right is inside the engine mount, that took a bit of time to find.

 

Brass. The core dimensions are the same, so heat tranfsfer will be about the same from a brass vs. al radiator. The aluminum/plastic design will probably weigh less, but I'd rather have a radiator that doesn't corrode as easily. I believe brass holds up better to corrosion, but that I'm sure is easily up for debate. (brass is ~ $30 more)
I don't know if the LR stock radiator is al or brass.
Regardless of type, my main interest was moving away from the LR stock radiator which is easily prone to corrosion/blockage due to it's tight core dimensions and pipe bends etc.