Mangled03gmc

iTrader: (95)

Is there supposed to be a hard spot on these lsx engines. When I rotate it by hand it comes to a hard spot in the same place everytime. By the way it is a 6.0. I have the plugs out so it isn't comp related. could it be the oil pump. Is it a gear pump or piston pump.. any help is greatly appreciated..

dirt track racer 81

iTrader: (45)

check for nicks in the crank.. thats if its been pulled..

goshawk23

i have a 6.0 on the stand now and there is no hard spot when i turn it over. i don't have the oil pump still connected though. i would think it should be a smooth rotation throughout.

dirt track racer 81

iTrader: (45)

i dont think the oil pump would create a hard spot though..was the motor put together?? if so i would pull it back apart, if you hard a nick in the crank its not going to last long till you spin a bearing..

Mangled03gmc

iTrader: (95)

Ok So would it make a difference if it was up side down on the stand. I was just thinking that there is some oil in the pump that crating pressure to cause it to do this. It can be turned past that point but it gets hard to. The motor hasn't been apart other then me having the pan off to check it out. Is the pump a piston or gear pump?

Thanks again

1slow01Z71

iTrader: (36)

oil pump runs of the front crnak snout. The oil pump isnt causing the hard spot I would look more into something dragging. Is it a smooth bump or or is sharp if that makes any sense?

willyfastz

Oil pump is a gear pump drivin off the front of the crank, just pull the cam cover (front cover) and pull the pump off and urn it. That'll make you fill better about it being the pump or not. Shouldn't be though.

Mangled03gmc

iTrader: (95)

Ok I found the problem.. After thinking the worst, an getting ready to call this guy and let him have a peice of my mind, I decided to pull the heads off.. Come to find out there was a huge amount of carbon build up on the top of one of the pistons, was not letting it go threw it full cycle. The motor was out of a wrecked truck so I guess it caused it to fall on the top of piston from the impact. So with the heads of it turned over no problem, smooth. i also checked the crank to see if it was bent and it wasn't.. So now I guess I am going to have a mild mill job done to the heads. Thanks to those who posted response's to help.. John

1slow01Z71

iTrader: (36)

just cause you cant see it doesnt mean its not bent. food for thought...

Mangled03gmc

iTrader: (95)

Actually i used a dial indacator on the end of the crank and it did not run out all. So with that being done and it turnig over no problem I guess i will find out when it has fire in it.I and a few motor guys i know seem to think it is ok. So we will see, I am keeping my fingers crossed.