I have a '97 SE7 and live in Las Vegas. When I drive, my temp gage stays below the half way mark, but when I turn the car off I hear a sizzling sound from what seems to be my overflow tank. When I turn on the A/C it stars to over-heat after some time. Shops say that it is my radiator, but whats funny is when I squeez my upper radiator hose (when running) i have no coolant flowing. I replaced the water pump about a year ago and t-stat a month ago. Please send some light my way.

P.S. does anybody know what size the plug is on the radiator so I can out a metal one on. Instead of a plastic.

 

I dont understand how you know there is no coolant flowing.

The plug is 1/2 pipe thread.

 

Yup, your radiator is clogged/restricted. You need a new radiator.

 

I'm sorry first off, hello fellow disco owners. I have been a disco owner for 1 1/2 yr. I love her we have our battles but we get through it. Ok so my dumb question is does coolant flow from bottom to top or vise versa? Every time I squeeze the hose when cool or a really hot engine it feels like nothing is flowing everytime. I am not a mechanic so of course I could be wrong.

 

The coolant always flows from bottom to top, cool engine coolant comes out of the bottom of the radiator and is pushed through the engine by the water pump.
It gets picks up heat from the engine and carries it to the top of the radiator.
It then flows across the radiator and back to the bottom of the radiator to be pumped through the engine all over again.
If you had good coolant flow the upper radiator hose would be hard when hot, in other words you could not squeeze it much.
First thing you need to do is double check the belt routing, it is very easy to put the belt on wrong but it looks right, if on wrong the water pump will turn to slow.
http://www.roverparts.com/TechTips/s...g_defender.cfm
If that is correct then you need a new radiator.

 

Ok thank you spike555 I will look at that.I think it may be on wrong. Also were can I buy a metal radiator plug. I just broke the plastic one. Half turned in my rad and the rest broke off. Any ideas how I could un screw the screwed in piece.

 

Are you sure it is PIPE THREAD? I saw this come up a while back and I believe I remember a disagreement regarding pipe thread vs another standard which escapes my partially compromised memory.

Can anyone verify please. I know brass ones are available from RN and I think AB but they are probably much higher than a good local supply house.

 

You can force in a 1/2 NPT plug, but it's not the correct thread, it's actually 1/2" BSPP. That's why they have a flange and o-ring.
I have them for $19 shipped priority mail.

You might not need a new radiator. Pull yours and take it to a radiator shop. They'll tell you if it's too far gone, needed to be rodded, or needs a recore. All are cheaper than a new one.

 

Thanks Tom, I knew I had seen something about this before.

 

Ok so I had the belt on wrong. I put it on the right way. I can't see if I have a bad radiator because I broke the plug and it has a hole in the center, and it is leaking out of it. Thank you everyone for all the help.