[JaxOsloBlue]

Before I turn to head gaskets, want to rule out some things first. $138K miles, 2001 Diso II. Yesterday on way back from beach, started to overheat. Pulled over, notice it was belching coolant from the around the base of filler cap. Let it cool off for an hour, added fluid, continued on. I could drive for about 5 mins and temp would stay level, but no hot air coming from vents with heater on. Then after five minutes temp would slowly rise. I stopped, fluid spilling from filler cap and let it cool off. Proceeded forward again with same result at which point I called for a tow home. I did notice the top two hoses from thermostat were rocket hot, but buttom hose from radiator was literally cool to the touch. Today I replaced the thermostat (old one was only a year old). Just went on a test run and got the same result; level temp on gauge for five minutes, then it slowly starts to rise. Once stopped, fluid continues to leak from filler cap until cooled. Running to get a filler cap now. Any chance the water pump (only 1.5 old) is malfunctioning?

 

[JaxOsloBlue]

Ok, added new expansion cap and think I now got up to eight minutes of running at perfect temp before it started to climb upward. But in the end same result, starting to overheat and still no hot water to coils.

 

[Disco Mike]

You really need to stop driving it or even head gaskets won't help. That engine will only tale a couple of over heats and it is then a boat anchor.
How mechanical are you?

 

[03DiscoJay]

did you make sure you bleed out useing the bleed screw and also turned on your heat wile adding new coolent? i had similar problem took a like 3 gallons of coolent an air bubble could cause such problems. also make sure you not leaking fluid from your timeing chain gasket.

 

[Disco Mike]

You only bleed the system with the engine off and cold, you only turn on the heater once you restart it and recheck the fluid level once it sits overnight.
That being said, you have more going on then just a coolant cap failure

 

[JaxOsloBlue]

Wish it was just an air bubble. I took off bleed screw, raised the expansion tank out of its cradle and added fluid until it came out of the bleed screw. Should have enough fluid now, but still not getting heat to heater core when warmed up. And top two hoses from thermo get warm, but bottom hose from radiator to thermo has yet to warm up. Not hearing anything terrible out of water pump, but any chance its not spinning? If warm fluid is truly flowing to the core, how come I'm not getting heat into the cabin.

Mike: How mechanical? I've rebuilt drive shaft, replaced pwr steering pump, water pump, bearings, brakes and similar.

 

[Disco Mike]

Your guessing with no specific direction. If you want help, PM me your number and I'll call you today.

 

[JaxOsloBlue]

First, thanks Mike for help in trying to diagnose problems. As always, a wealth of info and goodwill. Ended up taking Disco to shop because I just didn't have time.

Shop said radiator was in bad shape, so replaced radiator, throttle gasket, and water pump. They also did a chemical test and determined that heads weren't perfect, and were beginning to seep, but were not thought to be the cause of my overheating under load.

After those repairs, rig still behaves the same; temp is fine at idle, but as soon as its put under load, overheats within minutes. Shop says its a sleeve or crack. Basically have a boat anchor as Mike says.

So now what? Absolutely love the Disco, its my daily driver. Intended to drive it "forever". Quoted a rebuilt engine out the door in the $4K range. Its 2001 w/ 138K miles. I have asked shop to assess condition of everything else. Speaking on pure practicality, I need a car. Is it worth putting in the $4K? Where do you get a used vehicle for $4K that you absolutely love? If a perfect world and installation of rebuilt unit went well, any idea what I could get out of the vehicle going forward? Lots of questions. Heartbroken. Welcome anyone's advice. Thanks everyone.

 

[MoShadeTree]

As I was reading this post... I was thinking basically the same as the shop. Clogged Raditor and perform coolant test. Since you said you are capable of working on the truck, I would recommend that you pull the heads and have them checked for being warp. I did head gaskets and took the heads to a local machine shop and all it costed me was 2 weekends and $525 (gaskets, machine shop charges, oil, coolant, etc) You can find an 99 - 02 for $4K but I doubt if it will not need work. I would not pay a shop to do the work. If you don't have time to sort the truck out, then your choice is buy another one or buy something different.