My new Disco 1, hello from Socal
 

99 Disco 1 with 135k miles, aftermarket front bumper, hella lights and 265/75/16 BFG AT's. Her name shall be "Hell Bitch".

Got some catching up to do here. Lol. Repaired leaky head gasket, replaced fan clutch (oem), hard wired fans to ignition source (switched), 180 t-stat, double coolant flush (4 day process) and 150 psi blowout of coolant system, engine oil flush and changed fluid/filter (lucas oils), added lucas trans additive to trans and tcase (shifts good, looks good, will change soon), changed spark plugs and changed driver side window motor. This rig was in decent shape. Replaced a few vacuum lines, clogged pcv and cleaned all the air fuel sensors. Runs and shifts great. 4x4 engages and diff lock works amazing. Needs paint and will either go with Coyote or olive drab? I have some 285/75/16 bfg at's coming my way next month. All for now, carry on..

Here's a pic.

Atta Boy! Looking good.

Thanks man.

Well took her out for a long spin and she overheated.... Coolant was boiling in the coolant expansion tank. Coming out the cap! Seemed to be fine in park and neutral but would climb as soon as there was a load on the engine (drive). Did a deep flush twice with prestone coolant flush, blew out all coolant lines and radiator (adapter I made) with 150 psi compressor. Idled fine past 2 days (30+ minutes) and quick spins around the block. She ran great! Thought I had it fixed... Maybe trans is all clogged up? Not circulating coolant right? Shifts smooth and has no weird noises. Gonna drop the tranny pan this weekend and check everything out. ZERO oil in the coolant and ZERO coolant in the oil.... Any ideas?

How exactly did you "repair a leaky head gasket?" Doesn't sound like you did a head gasket job. One of those snake oil solutions?

You most likely have a radiator issue. No amount of flushing
will help that. Most likely clogged. You can get a D2 style for around 200 on ebay.
I'd check thermostat too. Water pump flow. And the space between the condenser and radiator for debris. It likes to gather there. Also belt routing. I guess it's easy to route the belt the wrong way and get the water pump spinning wrong.

Its not recommended that you ever ever let the truck get to the boiling point. These trucks are very sensitive to warped heads and catastrophic damage from overheating. Since you have a 99 get an Ultragauge. The factory temp gauge is crap.

With regards to colour, I vote for sandglow.

New tstat and belt is routed correctly. Had trace amounts of exhaust in my coolant (neighbor had tester). Use Blue Devil/demon sealer as I've used it before and it has worked great. Retested after running it's course. No exhaust gasses in my coolant. She's not eating coolant, burning oil, leaking at all. Gonna go with a we radiator I guess. Doesn't make sense tho, as she's only overheating under load.

I have a tech tool that reads real time engine stats. Idle and driving around town it runs at 205-215 all day with no tstat... Any load on the engine and it'll climb.