My buddy has a 1999 Expedition w/ a 4.6 and 190k. It has absolutely no compression in 3 cylinders. The plugs were unbelieveably fried. Never seen em that bad. His coolant looks like green swamp water I.M thinkin some of the valves are toasted 2, due to 0 compression. Apparently the car was blowing blue smoke, when it was running. The timing chain and components look ok, a little loose though. The cams seem to be in pretty good shape as well, aside from the couple of pieces of paper towels clogging the return on the oil filler tube side. I'm just about to remove the cyl heads. You think i'm wasting my time, and his money, sendind the heads out to be remanned, changing the timing chain +, buying all the gaskets ect, just to find the rings are shot, once I get it running?