2002 D2 4.0L
Not mine, but a friend of a friend. Don't know how often or how far it overheated before it was towed to my friend's house 3 years ago. Apparently at some point had a leak because there was leak seal everywhere it shouldn't be. We ran several different cleaners through the system, and finally straight vinegar for a few days starting it and letting it circulate, then letting it set. At some point, my friend pulled the radiator, and rodded it out himself with a wiper blade refill metal runner.

It can idle all day, but as soon as it is under a load, it starts to overheat.

Finally towed to my house for head gaskets, as we figured that was a possibility. No coolant in the oil though, and combustion leak test negative.

Compression test showed the following:
Left bank front to back: 135, 110,110,90
Right bank front to back: 135,100,120,110

Pulled the heads this afternoon.. The cooling system is pretty calcified and rusty. Water pump impeller rusty and pitted. Heater pipe to intake manifold seized with corrosion as I couldn't remove it from the intake. Water outlet pipe rusty inside.
Head gaskets intact as far as I could see though it was getting dark. What rather surprised me was how easy the head bolts came out. I've heard stories of a 4' cheater pipes having to be used. I am 5'9" and 140lbs. I broke them all free with a 18" breaker bar and minimal effort. If they weren't torqued previously, wouldn't that have shown on the combustion test, or something?

It's going back together tomorrow, with a set of machined heads from my old engine (also 4.0 non SAI). Since the gasket wasn't blown, I am assuming the 90psi on cyl 7 must be a valve problem, and should be solved with good heads. Also replacing all rusted heater and outlet pipes with good spares I have in the garage.

Is there anything I am missing?

 

Did you happen to perform a leak down test? Our blocks are known to fail from either slipped lines or pinhole leaks behind the liners. A block pressure test will tell you or a leak down.

 

No I didn't. I am going to weld shut one of my old water pumps, then fabricate some block off plates to the water jackets on the block so I can pressure test it.

I'm not in any huge hurry to get this back together, considering it has been sitting neglected for the past few years.

 

Something to add that I realised this morning: The driver's head gasket had been previously installed upside down. I didn't realise that last night as I was fairly inebriated by the time I got the heads removed. Today, as I was inspecting the gaskets, I remembered I had bent down a corner of the upper front of the driver's gasket. When I repositioned that gasket to how it was on the block, "TOP" was against the block.

 

Finally got the basket case all back together. Took a while to start. Had to spray starting fluid in the throttle body to get it started, but after that, starts every time. Definitely have to replace the idler pully bu the PAS pump. Noisy as heck. Let the spilled gunk burn off the engine and get to temperature.
Felt like a misfire, checked with scanner. Yep. P0300, P0301, P0306, P1300, P1319. The P1319 is because there is very little fuel in the tank (less than 2 gallons). Worst of all, I was checking temps on the scanner and shut it down when it got to 212*. Going to bleed it tomorrow morning. Hoping for an air pocket, but given the lower radiator hose was cold to the touch, I think the radiator is still clogged.
The misfires are also bothering me. New plugs and wires. Going to pull the plugs tomorrow mornign and see how they look. Might swap wires with originals to see if new wires are **** from the box. If plugs and wires don't change anything, pull plenum and swap injectors I guess.

Unless anyone has any better ideas...

 

Dumb question.
Did you look at night when it was running to see if you had any cross fire from the wires to the block or valve covers?
Had a nice glow from the 2000 when I had those codes.

 

Just went out and checked: No light show. Since the plugs and wires are brand new, and since cylinders 1 & 6 are side by side on the same coil... I wonder if that coil has failed either while parked for 2 years, or while sitting on the ground next to my garage door for 2 weeks.

If the plugs look good, I think I'll swap it out with a spare I have.

Don't have a spare idler though, dang it.

 

Misfire mended. Both plugs looked good. Smelled slightly gassy. Removed wires from the driver's coil and was considering attempting to change it without removing intake plenum. Then decided to swap wires instead, so plugged everything back in before changing out the two wires. Just for grins fired it up, and no misfire. Must have been wires not fully engaged in coil.

Let it idle for a bit watching temps on scanner. Got above 200, heard the condenser fan come on and shut it down. Upper hose is hot and very firm. Lower hose is cold. All of the radiator is cold. Radiator leaking at the seams where it was put back together after my friend rodded it out in an attempt to clean. It's going to need a new radiator due to the leaks, and I highly suspect it is still clogged.

 

The rad from O'Reilly's works great on my truck and was cheaper than purchasing online.