Topic: ticking and gradual power reduction

[bestos]

yo,

had ticking when i accelerate for about the last year.  and power has definiately dropped.  I KNOW for certain that i cant see the stud/nut on the rear hole for the exhaust mani (so i'm sure it leaks there) BUT when i put my hand behind the motor along firewall, i Feel relatively cool air moving back there (not exhaust gases). 
is it is possible my real power loss is coming from a bad head gasket on the very back of the motor?  i dont have any water/oil mixing.  I have replaced my cat, which did help things some, but i know that ticking during acceleration is telling me something and so is the blowing air.  Any thoughts?

[bestos]

yeah, and i know -- compression test is forthcoming over my 2 day break next week.  I want to see how the 4th cyclinder stacks up against the other. 

i really believe the very rear of the gasket is blown and b/c there are not the water/oil ports back there, i will only see a compression prob.

[VA_YJ]

It could also be a burnt valve.  The compression test will find that also.  You can buy a fitting that screws into the spark plug hole to allow you to put air (pressure) on the cylinder (not too much now!).  That may be useful for diagnosing your problem.

[bestos]

called a LEAK DOWN test correct?  just making sure i got the right test.  that checks the valves of a particular cyclinder after the compression test shows i have a problem right?