How much play should a valve stem have?

Does this engine have decent compression? How may miles?

There shouldn't be very much play in the stems. They are inside brass guides and the guides do wear out. When worn out, it is a waste of time to put new seals in it, they will wear out or pop off fast.

Are you chasing symptoms of worn out valves?

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

William Oliveri wrote:

The compression readings my mechanic gave me were 150 psi across all cylinders. I'm getting blue smoke after idling for a few minutes when I press on the gas. It doesn't smoke when keep the gas peddle down for a length of time. So I'm chasing symptoms of worn valve seals according to what I've learned.

Can the brass guides be replaced and if so how much of a job is that? Does the head need to be removed to replace the guides? These are exploratory questions.

Thanks,

Bill

You are basically talking a valve job. The seals are fairly easy, the fix just might not last a long time if the valve guides are sloppy.

Mike

William Oliveri wrote:

Please define sloppy. How much play, if any, should the valve stem have?

exploratory

Ok, had to go look it up.

In reality almost no play at all.

If you have the spring compressed or off and the valve loose from the seat about 1/16 down, then the most allowed side to side up at the top of the valve stem is 0.003" to call it not worn out. Specs call for

0.001- 0.003".

That sure isn't much. Any more and it will burn oil pretty bad as well as start wearing out the seats.

Mike

William Oliveri wrote: