I replaced my engine a few months ago because it was chocolate milk on the oil filler cap after an overheat. It's a 1994 with 220k on the clock. I replaced it with a low time 1995 engine and it's been working great.

I finally got around to taking apart the old engine to see what the problem was. But I can't find the problem. I was hoping it was a head gasket, and then I could replace the gasket or build the engine as a stroker. But the head gasket is in great condition. In the pics you can see where the majority of the sludge is and that was the only real part on the head. In the block by the lifters is where some sludge is as well, but only there. The sludge is only between the fourth and five cylinder (from the front back, not the firing order). The rest of the head is fairly clean.

So, is it a really small crack in the head? Is there a crack in the block? It's pretty hard to see down there. I cleaned it best I could, but there's still a little sludge and it's hard to see down there. If it's not the head gasket then it has to be a cracked head or cracked block, right?

I was hoping to rebuild this as a stroker, but now I'm thinking the engine is junk.

 

Take the engine to the scrapyard. It's not worth rebuilding, or even wasting the time and money to diagnose where the crack is.

 

I agree, the 4.0 is a dime a dozen, no sense in spending money on a block with a known problem.

 

Yeah, that's what I'm thinking. But you agree? If water isn't getting in through a blown head gasket, then it's a cracked head or block?

 

Or both. As I said, not worth spending time on.

 

Boat anchor.