Struggling with cooling issue still. Had a spurting leak in expansion tank: replaced tank, Flushed system, New Thermostat, and bled system. One problem ... when traveling up hills the trucks begins to overheat. When the heater is turned on it blows Hellishly HOT. At idle the gauge stays pegged just below the middle-line same during normal driving (45-55mph) but after a only a few hundred feet of up hill driving it rapidly climbs.
Fan is turning (enough?), and belt tensioner and belt are 1 year old. Haven't heard the electric fans engage for awhile, but those are mainly to aid AC cooling correct? Any ideas what to check/replace next? Radiator? Fan clutch?




Oh ... this is on a D1 with 118K, from 1998

 

Your radiator is restricted.

 

Any suggestions where to get a replacement?

 

Is there a "higher capacity" alternative?? When I replaced the radiator on my Jeep XJ Cherokee a few years back, I went from a stock "double core" to a "triple core" and got about 50% more cooling capacity. While it's less of an issue on the Disco, I'd sure like to be able to shed excess heat more readily, particularly in the summer under extreme use!

 

DI's have a 3 core radiator and DII's have a 2 core.
Any radiator shop can rebuild your radiator if you take it out of the truck and take it to them and they can very easily make it a 4 core radiator if you want them too.
$200-$300 to have yours rebuilt, $600 for a brand new one.
It will take them a couple of days but its well worth it.

 

The AC fans should come on when the engine gets hot, even if the AC isn't running. But the engine should stay at normal operating temp even without them.
Make sure your viscous clutch is good, there are several threads here about them.
Make sure your radiator fins aren't clogged with debris, you can do that with a garden hose sprayer from the fan side of the radiator.
If both those check out, follow Spike's advice and have a radiator shop check out your radiator.
Around 2005 I had the same issue and ended up needed my radiator rodded, about $65. Unfortunately it was corroded enough that it started leaking a year later (the crud in it was actually plugging the leaks) so I had it re-cored. The shop will tell you if your tanks are in good enough shape for a re-core. I had them install a coolant drain **** on the bottom left corner at the same time to make coolant changes less messy. Mark a spot so it will clear obstructions before you remove it.

 

FWIW - I paid $125 to have mine rebuilt here in CO.

 

Check also for codes on low vacum lean fuel. Check to see if the fuel regulator hose is not disconnected.

 

I was told that DII's radiators could not be rebuilt. I ordered a new one from Atlantic british but does that sound right?

Dave

 

Any radiator can be rebuilt or "recored" as it is also known.
Does not matter if it is from a DII, a DI, a Jeep, Chevy, Toyota, Honda...you get the idea.
Talk to a actual radiator shop, not a mechanic.
You will have to get out the Yellow Pages and look one up.
Just tell them that you need a radiator recored and take it to them.