Ok guys, a member of our forum asked me to look at his DII, no heat. The dealer told him he needs a new radiator.
He just dropped it off and I spent the last half hour looking it over. Here is what I have found so far.
It was low on coolant, topped it off and bleed the system.
Upper hoses get hot, top of fan shroud gets hot, heater lines get warm, not hot but very warm, both supply and return lines. No heat inside the cabin.
I let it idle for about 20 mins, no heat. Temp gauge is normal.
Ideas? I am going to let it sit in the garage over night, I am going to pressure test the system tommorrowand re-bleed starting with a 100% cold engine.
Any other ideas?

 

Make sure that the heater box doors are operating properly. By changing the temp rapidly you should be able to hear them move. It sounds simple but, you kick your self when that ends up being the problem.

 

do rovers have a heater control valve that lets coolant into the core? If they do, I'd check that.

 

I was thinking the t-stat was bad, but the temp gauge is normal and the top of the radiator gets to hot to touch. As with the upper radiator hose's, I tried to sqeeze them to see if they were full of coolant but they were to hot.
Keep the idea's coming. I think that it is a simple fix, but I just want as many ideas as possible.

 

looks like they do have a heater control valve..I'd about bet money that is the problem.

http://www.roverparts.com/Parts/BTR4022.cfm

nevermind thats for a D1..maybe DIIs dont have them?

 

I will look and see if it has that valve or not. I will also check the operation of the blend doors.

 

It looks like the DIIs have a temperature servo attached to the heater housing. I don't know if that control's the fluid flow or if it it for an air flap.

Willie

 

Ok, here is where I am at. Bled the system last night, no heat.
Let it sit overnight.
Topped it off and this morning heat, kick butt heat too.
Rented a cooling system PSI tester from AutoZone and it wont fit the truck. So I have to look for leaks the hard way and so far I cannot find any.
I am letting it cool off right now, will look for leaks when I can touch it.

 

Ok, done.
I can see why you guys like your DII's, the interior is very nice, but man, working on the thing is a PIA.
Took me a hour and lots of skin to reconnect the lower radiator hose to the radiator.

 

I'm betting its the temp servo attached to the housing... I've actually had this problem.