I recently bought a 87 F-150 with a I6. about 2 or 3 weeks ago I noticed a slight clicking noise that was not there before. Now it has devoloped into a knock. I had low oil pressure so I thought I would replace the stock pump. I would up having to replace the pump with the oil pan still on it. (that was very much fun). I thought I should check to see if there was any junk still in the bottom of the pan to see if the pick up tube could be clooged with. I found a good size piece of metal. I thought it could be a piston, my father and in law thought it was a bering, so did the guy I took it to to have it checked out. turns out I was right the guy who check it was able to get the pan off and found another piece in the pan. the pieces match and are in the shape of a piston. I forgot to ask the person if there were any other pistons that were cracked. I told my Uncle who, builds engines, about it and he said that if one was cracked there is a good chance that there are more that are cracked. does anyone have an idea of what could have caused the pistons to crack?
I'm probabley going to have the engine replaced and I want to make sure that it does not happen again if I can prevent it. All ideas are welcome.

Thanks,
Knightrider77

 

Don't know how many miles are on the engine... but here's a few causes..

Wrist pin(s) start to seize up, making the piston "rock" in the bore. Eventually the rings will break up and sometimes the piston will, also.

Lack of lubrication.

Detonation (pinging)... tears the hell outta pistons.

Overheating.

Mixture too lean.


The I-6 is a stout engine. After a quality rebuild, good maintenance is the key. Change fluids and filters regularly. Use the correct octane fuel (see owners manual.)