1994 Explorer Engine Swap

[muddinbronco87]

I bought this Explorer with blown headgaskets and am getting ready to put engine in but I have 2 engines and not sure which one I should go with.

Engine #1. Its out of a 94 with roughly 70k miles and was supposed to run great its the engine the p.o. was going to put in it. When I pulled the spark plugs, plug #5 was really black and the rest looked good. What could be the cause of this.

Engine #2. I pulled out of my 91 Explorer Automatic that has about 60k miles on rebuild, engine runs great but I've read I'd have to swap over some parts off the 94 engine to get it to work.

If that black plug on the 94 wasn't a bad thing I'd rather swap in that motor, just wondering what you guys thought.

Thanks

 

[MrShorty]

The usual problem associated only with the #5 cylinder onthe 1st gen OHV is problems with the intake manifold gasket. This engine has a tendency for the lower intake bolts to work loose, which allows coolant and/or oil and/or air to leak into the #5 cylinder. (This issue is often accompanied by a pinging/detonation. You'll find a lot of references to it by search engine ping or similar). Often the issue is resolved by simply tightening the bolts back down. It might be difficult to see if that's all it needs until you get the engine installed, though.

There are certainly a few parts that would need to be swapped onto a '91 engine. Recognize that '91-'94 long blocks are the same, so you don't have to do anything any deeper than that.

 

[biggs92EB]

go with the newer one, i little more power, direct fit, and oem standards. IMO

 

[marragtop]

I would definitely go with the 94.

 

[murrayexplorer]

Mr. Shorty- I have a '93 Sport that goes through quite a bit of oil and coolant. I have a new radiator and lower radiator hose and there are positively no leaks anywhere. Your comment about the intake manifold gasket caught my attention because, as of late, I have been thinking about swapping engines from a wrecked Explorer my in-laws have. I'm going through oil, coolant, pinging when I run it a little hard, and now some hesitation and consistent, high rate "missing" that happens for a few miles before it smooths out; the smoke, on the other hand is a constant I've learned to live with. Other thoughts regarding a diagnosis are head gasket, rings, and/or valve guides; maybe a combo also. I really don't want it to be rings. Any help/opinions/ideas/solutions would be greatly appreciated.

 

[muddinbronco87]

Okay well I think I'm going to go with the 94 engine than. Can I tighten the lower manifold bolts without taking off the upper? How hard would it be to change the gaskets out once the engine's in if I was to end up having to change them?

 

[wood1]

Sure you can tighten the intake bolts without taking the upper off. You'll know right away if they are loose. A few of mine were barely finger tight. I think there was a couple that I needed a universal joint to reach.

 

[Blacksheep Josh]

No one mentioned it, but with the 94, the engine will also have EGR while the 91 and 92 do not. Which means if you went with the earlier engine, you'd have to get another computer, and cut out one 02 sensor. So you made a wise decision with the 94