a strange story of squeal
got the dreaded squeal on my '02 3.0 flex ranger. read a lot of great post here, and all over the net trying to track it down. throughout used a mechanics stethoscope to try to find the problem.
replaced (in order):
PS pump and pulley(damn thing is still growling after vacuum bleeding three times!)
Alternator (little squeak in it with belt removed)
at this point i figured that it was probably engine related and not belt drive. took the belt off, and sure enough, still squealing like a pig. i feared the worst at this point, cam bearing shot to hell, but it only has 76k on it! did a little research and found out about the cam syncro, so i replaced it. figured it was a good thing to do after i stumbled across all of the horror stories (damn fine piece of engineering there, NOT!). but afterwards it was still squeaking!
I finally noticed that there was one of the spark plug boots that was burnt looking. put my hand down there while it was running and felt a steady stream of hot air that increased with throttle!
strangest thing, sounded just like a belt squeal! is there that much backpressure in these exhaust systems?!?!
I've done exhaust gaskets before, and the manifold never seems to fit back on right, so i purchased the whole thing from napa for $60, bought some grade 8 equivalent bolts in 30mm and 65mm and a bottle of antisieze. used about a pint of aero kroil to loosen everything up (best stuff on earth, gonna start wearing it as cologne!) and everything came out with just a 3/8ths ratchet. finished the swap, nothing remarkable, and sure enough cured the problem.
so, if anyone else is banging their head against the wall trying to find a squeal, check your manifolds!