I went camping in April and my 95 disco started getting hot while wheeling. I made it home after refilling the coolant (with water) 3 times. Highway was fine. When I got home it was boiling over out of the reservoir any time I would drive in town. I ended up changing the thermostat, did nothing but it was only $4 so not thay much of a loss. I flushed the radiator the other weekend to work out air bubbles, and after idling it for 20 minutes, no boil-over, but also no heater. I plan on flushing my heater core this weekend but I'm thinking its my water pump. It's not leaking or making a noise but I do believe the spindles have rusted away because I have yet to see any type of flow going through the reservoir tank while its running. I want to Lear it down and look at it but I don't have a gasket to seal it up afterwards. Are there any other symptoms to a bad water pump? Is there anything I'm missing? Let me know.

 

Symptoms of bad WP include leaks, wobbling. RTV will do as a gasket. Read my posts at the bottom here on cooling issues, you could have a sludged up radiator inside and out, a wimpy fan clutch, etc.


Highway was fine because 5280 feet per minute of air flow. Slowed down, a blocked radiator and weak fan clutch can get to you. 180 thermostat is a good idea. Fan clutch when warm, engine off, spun, released, should coast to a stop in less than 1 revolution. Radiator when warm, truck off, should be within 10F top to bottom on fins in a vertical line. Your age radiator could probably use a rod out to remove calcium. Heat core and lines could use a reverse flush.

 

Thank you for the input, I'll check my radiator fins. As for fan clutch it doesn't have a lot of play to it. It doesn't free spin after shutting off the engine and I can't get a full revolution if I flick it. When I flushed my system there weren't any rust flakes but there were some white flakes here, possibly calcium. Not a crazy amount though. Before I went wheeling I didn't have any problems, now I can't drive it more than 3 miles without boiling over. What could overheating do to my cooling system to cause it to malfunction?

 

Just spent about $1000.00 replacing cooling parts just to find out the AC condenser was packed with trash. replacing every cooling part did nothing to affect the overheating issues, but a bit of compressed and no more overheating at all. So, before following in my footsteps, check to make sure the radiator is getting air...

 

Such a short time before overheating, assuming that coolant is full, belt on correctly (water pump not running backwards) - would point at something like a stuck thermostat, or one installed backwards (spring goes inside the block) or head gasket or cracked block or head. My truck hardly gets up to operating temp in 2 miles.