Hey all, I've been initiated into the exploded 4.2 club!

Only had this truck about six months. '98 F-150, 102K miles. Truck had been running fine, then one evening, I went to start it and was met with a "thunk" pulled the starter, had it checked, it was fine. Re-install after cleaning, "thunk." Give it another try, it turns over, then starts, but sounds like its gonna explode. Shut 'er down in horror and crawl back under to find a chunk of oil pan on the ground. Awesome.

Drained the oil, no OBVIOUS signs of coolant...

Pulled the engine, the front driver-side rod bent and broke near the crank, which is what busted the pan. Good news, (I think) is that other than a minor nick at the very bottom edge of the cylinder, nothing seems destroyed beyond the rod and piston skirt. And oil pan... Oil in the pan seems gloppy, not coating the whole pan, just kinda clumped in the bottom of pan, but the whole pan glistens like its wet.

Cylinder is clean, and the crank & other pistons spin freely. Praying the crank is ok, this is gonna be expensive enough. I'm hopeful a rebuild with new rod/piston will fix it.

It sucks because I really like this truck, its very clean, but the fear of this happening again has me considering fixing the engine and getting rid of it, as I couldnt afford another blown motor. Hell I can't REALLY afford this one, but no choice.

Intially I'm thinking coolant leak, but the oil *seemed* fine. Though there was some "chocolate milk" in the passenger side valve cover. I thought this odd since it was the driver side rod that broke....

Motors never been apart that I can tell, gaskets are all stamped Ford.

Whats your experience with repairing these issues? Are they prone to happening again? Are broken rods common to the coolant leak, or mostly just bent rods? Could I safely expect years of trouble-free service with a fresh rebuild with the better intake gaskets?

Sorry for the long winded post, half "thinking out loud," deciding what to do. Pictures to follow....and I'll check the build date sticker...

 

I rebuilt my 4.2 over 4 yrs and 46k miles ago due to a bent rod from bad intake gaskets. They are bad for leaking into the intake ports and hydrolocking the engine. I haven't had any trouble with it since.