Posted by Johnd [172.70.34.200] on Thursday, January 04, 2024 at 12:19:14 :
In Reply to: Stuck valve posted by David Sherman [172.71.147.182] on Wednesday, January 03, 2024 at 17:07:46 :
I would only remove the head as a last resort. You may create new problems like broken studs, rusted studs, etc.
First, since the valve is open, use the plastic straw on penetrating oil to squirt into the valve chamber thru the spark plug hole. Your goal is to get the oil to run down the valve stem into the valve guide. Use lots of oil, it won’t hurt anything if you keep it out of the cylinder bore.
Next, try to pull the valve down from inside the valve cover. I have used the points of a tie rod sperator at the BOTTOM of the valve spring to pry the valve down. You can use a socket or block of wood as a fulcrum between the pry bar and the engine block.. Don’t bend anything, gentle pressure is the goal. You might need to tap while prying to help it break loose.
After breaking it loose, my experience is that it will probably stick a few more times, and require repeating the process a few times. When you are satisfied, put the spark plug back in and run the engine with the valve cover off. Let the engine get to operating temp before putting the covers back on and going for a test drive.
I estimate a 75% chance of freeing up the valve without pulling the head.