I was driving my 78 cutlass home last wesday an started to notice a loud knocking from the top of my engine. upon pulling off the valve cover a noticed a loose rocker arm. the center bolt was tight but the arm had some side to side play. the valve spring was also loose. is the valve bad, or do i just have to replace the spring. could save me from pulling the head if its just a bad spring.
I also checked the push rod which seems to be ok.

 

could be more likely a collapsed lifter, or bent pushrod, also im not familiar with the 425's but dont most of those have rocker arm studs? make sure the stud is pressed all the way into the head, ive seen some studs on chebbys back out like an 1/8th of an inch

 

Could also be a worn rocker arm or rocker arm pivot.

- Eric

 

Only the '65 425's have rocker studs. All others have the normal rocker bridge and arms.
I'm thinking you have a broken valve spring.
Maybe a broken alum bridge, but that should be real easy to see.

Gene

 

broke it down and the spring was broke, replaced the spring an it runs fine. should I worry about the other 15 springs or is this just one of those rare things that happen?

 

If it ain't broke, don't fix it

"make sure the stud is pressed all the way into the head"

"pressed in" ?

Not on an Olds V8...

 

The '65 425 heads have SCREW in rocker studs!!

Gene