I have a 97 discovery that keeps over heating. any1 have any ideas why this might be happining?

 

I have a 98 with the same problem - it would run for about 20 minutes then start to overheat when driving at hiway speeds. Here's what I've tried so far, based on some of the posts and advise from friends:
1. Installed a new Thermostat (the genius that had the truck before me had removed it). That didn't help.
2. Replaced 2 dead electric cooling fans that sit in front of the radiator. Fans helped, but still the needle moves up to the high end of the zone when the A/C is on. Turning the heater fan on high lets the needle come back down to half way on the guage.
3. Poured in a bottle of "Water Wetter". Some help - not much.
4. Drained all the old coolant (went thru several cycles of draining, filling with water, run engine, draining, filling with water, run engine, draining...) until the little black pieces of crap in the drained water cleared up.
5. Just finished installing new upper and lower hoses tonight and put new Dex-Cool in the rad ( based on several posted reccommendations.) Also threw in a bottle of Water Wetter for good measure. Too late to take it for a test drive, so I'll do that tomorrow to see how all that turned out.

Will keep you posted to see if that did the trick.

 

Well, the flushes, new radiator hoses and fresh Dex-Cool seemed to help alittle. Not a complete cure.
Next stop - radiator shop.

 

Are you sure it's really overheating and not a faulty reading gauge?

 

Hadn't considered that - thanks for the tip!
Is this the sensor that is in front, just to the right of the thermostat housing (as you're facing the engine)?

 

update:
Had the radiator rodded and cleaned out.
No more heat issues.
Now to tackle the other minor things...