My 2003 Ford Ranger 3.0 flex fuel has a rough idle and throwing a misfire code on cyl 5 and it wouldn't pass smog here in California. It has 127,000 miles on it. It is NOT smoking or burning oil to any degree. No bubbles in radiator when running. I looked at the valve springs on that side and none appeared to be broken.I have changed plugs, coil, wires and all injectors check out fine. Idle control valve, maf and throttle body have all been cleaned. I had a compression check done and came up with 142 145 120 on passenger bank 90 63 and 90psi on drivers bank. The mechnic just called and said I need a new engine (he did NOTdo a leak down test) He seems to think it is the rings?? Is it possible that he is correct. Could it not be just a bad head on that side? Any idea on costs for replacing the head. I know I can get them locally for about 150 bucks a side. Any help would be appreciated.

 

How did the plugs on the driver side look? I think 63 psi is pretty high for blown rings or a hole in the piston, but yeah, anythings possible. If all the obvious checks out (which it sounds like it does), I'd yank the head and see whats up. Your parts cost should be pretty cheap, since the 3.0 is such a common engine. Not sure what it would cost to swap the heads out, I'd venture ballpark is around $1200. May want to search the forums (theres a lot more out there than ranger forums) and find a detailed how to. These engines are pretty basic and nothing beats doing a repair at the cost of parts.