only 50psi compression in cylinder 4... Help

Only 50 psi in cylinder 4 but all other are fine, took out shims but the compression stayed the same.
Smog check says it's running fine at 2500rpms but not at idle?
do I really need a head job???
Never ran funny or threw a check engine light.

 

sounds like a bad ring..can you hear it leak down? how many miles?

 

is that above or below the 3.4 waterpump

 

only has 123,000 miles, bad ring... dose that mean new engine?

 

So more likely it's a stuck exhaust valve... That means I'm taking off the head and taking it to a machine shop... Do the valves have to be removed before it goes or do I just take the whole thing down there?
And what am I looking at, $500.00 give or take for a valve job?

 

Take the whole head with valves still assembled.

 

thanks for the help. this is my first toyota... used to subarus were you never have to deal with such things.
Still curious about cost for work... I realize it's different depending on where your at. But we all know these ae "hard econimic times" or at least that what my boss tells me when I do the work of three people.