Engine locked sitting in driveway

[uptonkid]

03 with 4.0 I started checking the motor would back up but worn't turn in the right direction, pulled the plugs that didn't help, pull vavle covers , timing chains look ok. I did back it up until it locked backward and then back the right direction, two times I think and it will turn over. I think its still something laying in a socket or something. Any Ideas??? Thanks Rickey

 

[JDraper]

More info please...were you working on the motor before this happened? Did it just lock up out of the blue? How was it running before it locked up?

 

[uptonkid]

the engine has been running great, drove it home it sit overnight. No start the next day, I started out thinking batt starter, but the motor wouldn't turn even with a wrech it would turn backward. I pull the spark plugs, still turn only backwards (stopping at the same piont in the right direction) now with the vavle covers off and backing it up and fooling with it seems to turn in the right direction, heading back out in a few to start looking again. Thanks Rickey My bad it still is stopping right after TDC #1 there is a little slack in the back chain

 

[uptonkid]

Update,,, head gasket and a broken giude from backing up engine. What a pain, Thanks Rickey