Uh-oh chunks in the oil

[DaveB]

I pulled the pan on the 4.0 in the Grand Cherokee that my wife picked up that had an engine knock. I was expecting to see a bad rod bearing and crank but what I found was chunks of one of the pistons in the pan:sick: I'm wondering what would make the lower skirt from a piston break off ????

 

[scoutabout]

I'm wondering what would make the lower skirt from a piston break off ????

Being made by j**p.

 

[Herzog]

Being made by j**p.

oh please. Like IH never had any problems what-so-ever.

 

[wr250]

run low/out of water/oil
blown head gasket, causing a hydrolock condition, ie the starter moves the piston up faster than the water can bleed off then bang, broken piston.

 

[PREMIER.MOTORS]

Too much piston to cyl clearance. piston gets rocking back and forth until the skirt breaks off.