Uh Oh! Engine gone?
I just had the same problem with my explorer, except it also blew a head gasket and had about a 6in crack in one of the heads. I don't know how many miles are on your engine, but if it is over 100k I would look into getting the motor replaced, or rebuilt. These 4.0's seem to hold up well for some people, but not for others (myself)
The guys who replaced my engine said that a 4.0 would run like a scolded dog, but not for long. They said that on a v6 that the metal that they are made from is thinner than a v8 and wear out faster. So I learned my lesson from these engines (last one I will own). My advice to you is, don't waste any more money on this engine and try to fix it, I would take the explorer to a good engine shop and have it rebuilt or replaced. It cost me about 2800 for my new engine and that price was out the door. I wouldn't drive it anymore until I had a professional look at it either, you might ruin the core. Tough luck man, I've been there!

