Toyota Repair: Toyota-camshaft, valve, camshaft

Question
QUESTION: I have a 92 toyota 4 runner w/ 3.0 v6.  It has an engine knock, several people I know have listened to this engine knock it has and believes it is in the top end, I'm not so sure.  The #2 cylinder has 120lbs of compression, all the other cylinders has 150 psi, I'm suspecting maybe a valve problem of some kind, I'm wondering what a bad cam bearing sounds like?  this knock sounds like a "rod bearing" knock to me, except it does sound like it's in the upper end of the motor.....what do you think?

ANSWER: Sounds like a valve knock.  Have you ever adjusted your valves?  The lower compression points to a valve problem.  Are you smoking out the exhaust at all?  Could also be a worn camshaft / worn valve seal / bad valve spring.

Hope ths helps

---------- FOLLOW-UP ----------

QUESTION: Yes it is smoking a little.  I don't understand "adjust my valves", I thought there was no adjustment on that overhead cam.  Are they adjustable

Answer
I don't know if this engine has adjustments on the rocker arms.  You can check in a Haynes manual for this particular model to see if it does have adjustments.
Does the smoke happen mostly during shifting?  This would indicate bad valve seal.  You may need a valve job on that head.

Thanks
Vince