340 TECH needed

[txracer]

Well a long story cut short. My 340 quit running! Seamed to be locked up. Had towed home. Crank will turn 360 degrees then stops ( more of a thump a than a clank!) . Took starter out, then took valve covers off to check for a dropped valve, then unbolted torque converter, then pulled distributor, then oil pump shaft, then pulled fuel pump! And dang! It still will turn 360 degrees then stops cold! won't go past that spot.

Any ideas!

txracer

 

[wannadrag]

Pull the pan?

 

[txracer]

thought so

:icon_rambo:

 

[Coronet 500]

Sounds like one piston stopping at the cylinder head.My spun rod bearing felt like a small clunk,clunk with small back and forth at the crank,kinnda like a loose timing chain feels like.

 

[txracer]

thanks

thanks for the quick responses.
all so pulled all the belts to eliminate anything on the front of the motor.

 

[Cranky]

Did it make any noises just before it quit running? Oil pressure drop?

 

[74sundance]

Pull the plugs and stick a straw or piece of stiff rubber hose down each spark plug hole then crank the motor over and watch to see if all the straws/Hoses move if one or more don't move get ready to yank that motor.

 

[txracer]

dart

I pulled all the plugs and felt the tops of all the pistons. I put my magnet down in all the cylinders to see if anything came out. Nothing.

I have not checked to see if all the pistons are moving with the straw trick yet. good advise.

cranky. Didn't notice any oil pressure drop. But I was not paying attention to the gauge either! I was just cruizing along at probably 35 mph with my 9 year old daughter going to the Spring car show last Saturday night. And just locked up. No noises at all.

 

[Cranky]

Doesn't sound good. Magnet in the cylinder will pick up pieces of an intake valve but usually the exhaust valve has a stainless steel head and the piston is aluminum. If you pull the pan and see nothing wrong, I'll be surprised....

 

[74sundance]

Doesn't sound good. Magnet in the cylinder will pick up pieces of an intake valve but usually the exhaust valve has a stainless steel head and the piston is aluminum. If you pull the pan and see nothing wrong, I'll be surprised....

I'm with Cranky,sorry.Sounds like a busted rod is getting hung up on the crank when you turn it over.

 

[69 Runner]

Either that, or a rod stretched and a piston is hitting the head

 

[Bruce]

Pull the heads sounds like there is something in one of the cylinders hitting between the piston and the head.