locked up straight 6

[80f150]

My father in law has a 75 ford truck with the straight 6 in it, he was driving it then parked it for about 6 years, and its froze up, what can i put down the spark plug holes to loosen it up.

 

[Fellro]

If it was running, and then parked, it for the most part should be ok to just put some good penetrant oil in, not WD40, that really isn't a good penetrant. Check to see if there was any water when you pull the plugs to put oil in. It may be just a light rust that is hanging it up. You can bar the motor over by putting a socket on the crank.

 

[m78]

In 20 minutes you could have the head off. Then polish the cylinders put it back together and drive it for another 50k miles.

 

[O'Rattlecan]

Use good old fashioned motor oil in the plug holes. Take a little care not to completely saturate the plug hole threads with oil. It won't hurt anything, but it's not ideal to replace plugs that are totally lubricated.

Do you think it will crank on its own?

Ryan

 

[80f150]

when he stopped driving, he said it drove perfect, he just wanted newer truck

 

[Fellro]

I would just pull the plugs, use a decent funnel, oil it up with like Ryan said, motor oil or maybe a little thinner like atf or Marvel oil. If it is a manual you might try tugging it a little while in gear. Hopefully no water went down the intake while it was sitting.