Explorer Engine Swap

[k_williams1982]

For starters, I feel like a traitor to the IDI forum by posting here, but at least it's still a Ford right? I have a '91 Explorer Sport 4x4 with a 5 speed manual that I picked up with a blown motor. I'm putting a 4.0L from a '91 Areostar in it and I have a question. I found out that there is a difference in the camshaft between the '91-'92 and the '93-'94 4.0L engines. I won't be encountering this issue since both engines are a '91. However, I also found out that in the '91, there is a camshaft for an automatic and another from a manual. I can't see a difference in the pics, but they are different part numbers (off by one digit - the last digit too). Will this affect anything if I install the 4.0L from the automatic into the '91 Explorer with the manual?

 

[Optikalillushun]

i would say, no. the power difference will be negligable. Ford offered two ratings for the 300 (one for auto and one for manual, slight cam profile change) but both swap out with no issues.

 

[k_williams1982]

Well, I picked up a '91 Aerostar with a supposedly "running" 4.0L V6 in it. I got it from my mom's husband, so I didn't even worry about checking it over too much (I mean he's "family" right?). The transmission had been removed, so after some thought and research, I was able to take the motor out through the front by removing the radiator, bumper, etc., and removing the upper intake manifold before pulling it out. Well, went to drain the oil and found some problems. I yanked the valve covers off to find out even worse news. Here's some pics. The engine won't even turn over with a breaker bar! It appears someone just kept dumping "stop leak" in the poor thing until it just quit. So, I'm off the find an engine... again.

 

[k_williams1982]

Here's a few more pics. The heads are "caked" in sludge and crap. I'm so ticked off over this. A complete waste of my time pulling it, but at least I learned to checked EVERYTHING from now on, no matter how well I know the person.

 

[Optikalillushun]

wow that rlly sucks. looks like it had some water in it also from the rust.

best idea is to move on...no idea how plugged up the erl galleries or coolant passages are with sludge.

 

[towcat]

how gone is yours?
there's new heads avail if your bottom end is still OK.

 

[k_williams1982]

how gone is yours?
there's new heads avail if your bottom end is still OK.

I pulled the lower intake, heads and oil pan today. The pan had creamy oil in it, but the weird thing is that the coolant in the water pump was still green and cylinder 3 had coolant in it (also green - not creamy). The head gaskets still looked good, so I'm trying to figure out what happened to the engine. From some forums on Explorers, I've found out that it could have just been the intake gasket that went out. Most of the "sludge" appears to be sealant of some sort. A guy I know at NAPA says the heads aren't warped and that the head bolts don't appear to have suffered excessive heat (no "blue" color to them). The cylinders are smooth and still look good (cylinder 3 had a little rust starting, but cleaned up easily with some 600 grit sandpaper - only a few small spots). I sprayed the rods, mains, camshaft, crankshaft, lifters, and cylinders with PB Blaster and let it soak for about two hours. Now, the engine turns over easily. Don't know what to do now... I have a complete head gasket set sitting here so do I get the heads cleaned and clean up the block while it's all apart and put all new gaskets into it and then run both a coolant and oil flush through it, or do I just toss this engine and get an "unknown condition" engine from U-Pull It for $175 (after giving them this engine as a core)?