I have a '01 Disco II with about 99K on it and today it started running real rough, got a flashing SES light and the temp gauge rose a bit on it. It never red lighted with the temp but rose on the high side nearly to the red. Haven't had a chance to read the codes but trouble shot a bit and the radiator seems like it may be plugged up some. The input side is screaming hot then about 9 or so inches over it is cool to the touch and continues to be so the rest of the way to the output with the exception of about a 3 inch section almost directly in the middle of the radiator that is warm all the way across. The lower radiator hose is cool to the touch all of the time and at idle the temp needle stays in the normal range but the reservoir gets screaming hot and when you open the bleeder screw at idle it shoots about 2 or so feet in the air.

Does this sound like a plugged up radiator to you guys?

PS heater temps normal also

 

Check both your thermostat and radiator first. I would not drive it anymore until you find the issue, serious damage will occur if it has not already.

 

Replace the thermostat, bleed cold and recheck when warm.

 

Your description makes me think of a clogged radiator, uneconomical to repair, would have to be replaced. This is a horizontal tube radiator, so it should be hot on inlet side, cooling off as you go across. If you test top to bottom fins you may find bottom is much cooler (by more than 10F), which indicates clogged lower rows.

If doing the stat at same time consider the 180F model.

Note about temps - normal range is 180 - 205F. At 212F the electric fan should come on. Some fans are failed, and fuse blown, owners think everything is fine, no fan. Heat gauge continues to point at 50% "like a rock". When in fact the engine is already overheating. Anything above 50% is overheat. Use a scanner or Ultra gauge to see the real temps from the OBDII port, and you can tell if you are making progress with the repairs. No point going to 240 - 250F.

Note that head gasket problems make high heat as well, and usually leave products of combustion (exhaust gas) in the coolant. Hope you don't have bubbles running in papes sound under dash, which can be air or exhuast. There is a $50ish chemical test for exhaust in coolant. Changes color.

 

Don't do any thing including new parts at it before you have it tested. How mechanical are you? Have you been adding coolant lately, is the coolant low now, do you see any coolant leaks?

 

I just paid $208 for a new D2 radiator - that includes shipping.
There was no tax for me as the shop is in Texas.

RockAuto Parts Catalog

I'll get the rad on monday and let you all know what happens.

Your rover heated up so fast - I am thinking you lost some coolant.
Are the hoses getting bloated?
Hopefully not huge pressure in the cooling system.
Cause that means.... HG troubles.

 

It didn't lose any coolant, it was still at the normal level, it never boiled over and never maxed out the temp gauge but did go close to the red. The hose did move a bit when I unscrewed the cap the first time indicating quite a bit of pressure in the system.

T-Stat opens, and the electric fan didn't kick on and I didn't drive more than 2 miles when it started happening as thankfully I was close to home.

 

Took the radiator old and pulled the tank off. Here is what was inside of it, has the feel of jelly, seems to be some old stop leak from a previous owner.

 

Maybe some Blue Devil..... so would that blob in the tank have blocked off water getting to the rest of the rows? That would have been a small radiator for sure.

Check your fan (blade spins free), relay and fuse under hood; it should have come on. If electric fan starts to sieze, it will blow fuse, and you never notice that it is not coming on.

 

but besides the goo it looks rally clean inside ... no calcium