Hi

First I want to say I have been searching all over and have not found my exact problem, so that is why I am posting this. I have tried all the common things I can think of.

I have a 99 D1 with 135k miles on it. It has a 2" ome lift and full rock slides and bumpers (so it weighs a bit more) Its stock engine wise. My overheating problem started a few mo. ago. (its my fun or snow car only so I dont use it much.) I noticed that it would start to overheat only when I went up hill for more then a few min. ( I live in cloudcroft NM in the mtns) I never let it get out of the white lines so not to meltdown the motor. I took it into my friend and mech. and told him I think its the fan clutch, from what I read on the forums that made sense. We ordered one, then noticed my water pump bearings were bad and loose so I put in a new water pump too. Put in all the new parts and noticed I now have a hole in my radiator (gee I wonder how that happened) So I got a radiator and all the new parts in, filled it with coolant and water and took a spin. It was fine for a few min, Then shot up to hot. So I figured air bubbles. I spent the next 3 hrs trying to get all the bubbles out. I tried everything to get them all out... flat ground, a little angled all the way up to a crazy 45* angle. Its much better now, I can drive it on flat land up to 65mph and I can use the AC for a while, I can even idle for a long time, But as soon as I try climbing up the mtn road it overheats. I HAVE NO IDEA WHAT TO DO NEXT! Please help me. The thermostat seams to work. The heater is HOT. There is no coolant in the oil or vise versa, and the exhaust still smells like normal, not sweet. Could there be more air bubbles trapped in there? Any other ways to clear it out?

Any ideas or help would be much appreciated. I'm sure I must have missed something.

Thanks,
Colin

Here is a picture of it flexing so you can see how much weight has been put on.

 

Did you bleed the coolant system, are your 2 front fans working, how about your main fan, have you checked to see if the clutch is still engaging?

 

Well, I dont know if I bled the system right, (what is the right way) I put my nose up on an angle and kept the overflow tank open. Fans work when it gets REALLY hot or if the AC is on. Fan clutch seams to be working fine. (loud when it first starts).

Thx

P.S. I just checked the coolant for exhaust fumes using a chem. color change test and it passed. So it does not look like a head gasket.

 

Did you open the bleed screw on the top of the rad? open it, pour coolant in. Start truck with heater on full hot. Once coolant starts to move and the t-stat opens, fill and close bleed screw. top off reservoir and you are done.

Check that BOTH of your electric fans are working.

 

So what is up with the flexing in the Picture?

 

What have you done with your suspension? It seems that it flex a lot!!

 

once you drive a vehicle around enough after bleeding it awhile it will be low but fine. Especially on a d1. although its possible either the thermostat is screwy or the heater core is a bit stuffed. when its at an angle its makes a problem. Clean out the heater core with a hose and install new thermostat. Its a cheap fix. Plus make sure the hoses are installed correctly and make sure there is nothing impeding the radiator. To save on coolant loss, take a large hose and blow air thru it to create a siphon.

 

Sorry, I have not been on in a while, I was a little pissed at the truck, so I have just been driving my other disco for a while, but now the stock one has 2 flat tires, so I started working back on the green overheating one.

Yes it is still overheating up hill, better, but still unusable for the most part.

Here is what I done to it so far.

New (used but nice radiator)
new fan clutch
new water pump
new thermostat (I boiled both and the new one opened and the old one didnt)
I have also tested for blown head gaskets using a chemical test (some weird blue liquid in a turkey baster over the radiator opening LOL) and it said no exhaust fumes were in the coolant.
the ac fans to come on if the AC is on, and I think also if it starts getting really hot, (but I might need to make sure they are without the AC on. I know they stay on after the truck is turned off while hot.
Also I have found no leaks and there is plenty of pressure when I open the cap.

I dont know what else to check for??? It does seam to really overheat too, (using a therm. the heater in the normal range is 170ish. when it starts to overheat the air coming out of the vents is over 200!)

Could it be that the trans-fluid is old and is overheating, which is in-turn overheating the car? and when I say up hill, I am going up a mountain going from my work at 4k to my house at 7k feet in about 6 miles. it only starts to overheat at about the half way point. and if I turn around the temp drops right back down in about 1 min.

I have also never let it get out of the white lines, I pull over and let it cool down, as not to let it melt down. LOL

PLEASE HELP! I miss my truck and I'm sick of my stock one as its got its own issues ( It was a stolen and recovered truck that somebody really worked over)

 

Do you have an ODBII scanner so that you can see the actual water temp?

 

Send me your tele number and I'll call and walk you thru the next few steps.