One of the nipples on the thermostat on my Discovery II broke and I had to replace it. It keeps loosing over heating. I don't know if it's losing water but I'm not sure if that's from the overflow bottle bubbling. Does this system have to be bled of air? On some other cars (like my old Saab), they had a bleeder valve to let air escape.
Is there something I'm missing maybe? I don't think it's a head gasket because it's not blowing any smoke or burning any oil. From what I can tell, the same thermostat is used from 1999 to 2004 so I doubt I got the wrong one.....

 

Did you bleed the coolant system afterwards while the engine was cold, if not, it needs to be bled for starters and go from there. Do not drive it till this is resolved or you could toast your engine.

 

Can you tell me how or point to a procedure? I have done this before but want to make sure I do it right on this vehicle

 

just remove that bleed screw on top of the top radiator hose until a good flow of coolant comes out then close it. my car does best if pointed slightly up hill but I did my rover on flat ground and it seemed to work fine.

 

I found the bleed screw. If I was not looking for it, I would never have recognized it as such.
I'll work on it tomorrow. Either my battery is dead or the starter brush is worn as it's clicking and not starting. I'm charging it now. If I can get it started, I'll bleed the system and let you all know.

 

The LR has been holding fluid fine. I'm now thinking that either the water pump is going or the radiator needs to be flushed. I suspect the radiator as it seems to be moving fluid fine. I'm going to flush it today.

I had considered both since I have a bit of a belt noise. I think the tensioner is actually going. The parts guy at the local LR dealership said that the right hand side tensioner is known for failing. He also told me this model is known for sediment in the bottom of the radiator. I'm going to see if a flush helps.

If it doesn't, I'll loosen the belt and see how much play I have on the pump.

One question though, is there an easy way to loosen the belt?

 

Read the write up section, how the bleed the system is in there as well as other common questions.

 

I've read it and bled the system accordingly. I think the thermostat I got is bad. The lower hose is cold and the upper ones are very hot. I don't think I'm passing cold water through the thermostat. I'll get another one. If that doesn't work, It's most likely the radiator, even though it looks new.

I flushed it and it passed a lot of water freely. Yes I know that doesn't mean the radiator is necessarily ok but it's not too clogged. I also did not see any sediment being passed.

I'm not blowing smoke, the hoses aren't getting pressurised and the oil is not milky. Also, the fan is spinning and is resistant while it's engaged so I think the fan clutch is good. There is on play on the water pump bearings as I released pressure on the belt and tried to move the fan and it was tight. The belt has very little play.

That being said, it's either the thermostat or the radiator. I think it's the thermostat.

 

Lets hope so.

Glad you did your homework.

 

Just wanted to update everyone that I found my problem. The thermostat I got was bad as I suspected.