my mom has a 97 F150 4.2 with 100k that developed a rod knock so I located another 97 that had a 4.2 with 106k that was in a rollover accident. It has sat since last summer he for some reason had the gas tank off so you couldn't start it. We cranked it but the fan blade was hitting the shroud. Looked at the dipstick, oil looked good no sign of coolant at all. Pulled the truck in the garage today drained the oil and the first quart or so was straight green antifreeze then oil. They were completely separate so it didn't look like it had been ran that way. There's tons of "could be" so before I came home I put a fresh pan left the drain plug off and filled the reservoir. I noticed a very slight drip took a long time between drips tomorrow I will know just how much has seeped through. Not sure if the motor had a problem and he rolled it for insurance money and just didn't say anything or if something was damaged in the accident. The truck isn't that bad just the corner of the cab is smashed down to the steering wheel the rest has no skid marks or anything. I'm just trying to decide if the motor is worth fixing or if I should start looking again. I only paid $400 for the truck and it will junk for more than that so I'm not worried about losing out on money, I just don't want to waste time on junk. Anybody have any suggestions???? Thanks

 

Might be the timing cover gasket. Mine leaked to the outside, but it just as easily could have leaked to the inside ...

Here's the write-up of my repair ... https://www.f150online.com/forums/ar...150-4-2-a.html

 

Look again - the 97's and early 98's had bad lower intake and front cover gaskets that do exactly what you are seeing. It's either hydrolocked or getting ready to.

Look for an engine with a build date after 1/16/1998. Build date is on a sticker on the driver's side valve cover.

 

I'm hoping it hasn't done that, we turned it over and tried to start it before I drained the oil and knew there was a problem, spraying carb spray in the throttle body it backfired I hope it didn't lock right then and there. The guy never told me about a problem with it

 

It sounds as if that motor was probably on its way out before he ever wrecked it. With the intake gasket problems on that year truck it is possible to have a small amount of coolant leaking into the cylinders and still run, after a while it would eventually hydrolock and most likely bend one or more of the rods. Just because the oil and antifreeze were separated does not mean anything, oil is lighter than water and will separate quickly. I would advise you to pull off a valve cover, if you are impressed with how clean the head is it is for a reason...the intake gasket leaking. I just went through all of this! The timing cover as said above is another place to check as well. Hopefully it is just an intake gasket leak and no internal damage has been done, but even then it is still expensive $280 for that gasket kit at autozone.