1998 F150 4.2L, 200K Mi... wont turn over

[20HondAccord02]

I have a 1998 F150 XL 4.2L. THis truck has been the best vehicle we have ever owned. Bought it brand new in 98 and 200,000 miles later, I think it may have bit the dust. I got in it one day, went to start it and it turned over then made a loud bang. I tried to turn it over again and it struggled seemed to get jammed some how. I really am not sure that it could have thrown a rod just trying to start it. Doesnt a rod normally go while you have the motor under a little pressure? It isnt the started because I bought a new one to eliminate that possibility. Also replaced the battery to reassure that it was getting plenty of power to the starter. It seems like the engine is seized but i dont understand how. The truck ran great on my way to work and has never had a bit of problem. Have done numerous trips out of town and have never been concearned even one bit about it. The truck has seen the proper maintenence it has ever needed. It has never consumed oil or anything. Any ideas? I guess if i dont figure it out, ill pull the motor and rebuild it. I want the truck back to life!

[Winddrifter]

Have you tried to turn the engine over using a breaker bar and a socket on the crank dampner bolt? I assume it is possible that the timing gear might have slipped a cog. If so you might have a valve up against a piston. If you try the breaker bar bit, be carefull not to wrench on it too hard as you may cause more damage. 200,000 is a lot of miles if you have never changed the timing gears and chain ( or timing belt if that is what it has.)

[celkins2004]

!!! CAUTION !!! to all 4.2 v6 owners. proceed with care !!!

i just stumbled onto your thread and i'm glad i did. i just rebuilt my 4.2 v6 about five months ago. the engine only had about 107k on it, blew an intake gasket and that was all she wrote.

the only thing is, it happened exactly like you said. i baby my truck, have all the repairs and scheduled maintanence on time and by the book. i even took it out the night before to grab a bite to eat. it never showed any signs whatsoever any time before. got in it about noon the next day, and when i got on the ignition, all i heard was this clank. it was as if someone hit the block with a sledgehammer. the truck never even cranked. i got out and looked under the truck and oil was pouring out. a rod had broken and hit the oil pan.

thank goodness nothing else was hurt. two pistons, one rod, a set of rings, oil pump, timing set, new oil pan, crank polishing, heads gone through with two valves replaced, upper and lower gaskets and new bearings all around later, we're up and running. about $1700 later (without labor, considering i did it myself) all is fine.

i suggest anyone with a 4.2 v6 (1998) go through and replace intake gaskets before or around 100k. in my opinion, this will save them money in the long run. i personally know of 8 instances that this very same thing has happened.