wierd noise

[liquidblue]

Maybe someone can help; I have a valve train noise on my 96 Trans am that shows up after one minute or so. It’s sort of like a chirping noise coming from one valve. I have checked the lash and it is fine. As I bring up the rpms it does not get any louder almost goes away. I ran some cleaners through the engine and it is still there. I was told to bring up the rpms to almost red line and the noise stopped for an hour or so, then came back. The lifter is still bringing oil the rocker and everything looks fine from up top. It seems to be the opposite of everything I was told about a bad lifter. If anyone has any ideas or have had this happen to them please let me know.

Someone told me this could be carbon knock due to the fact that it is not present when cold. it only starts up as it get warmer. and seems to go away at highr RPM's any ideas?

[liquidblue]

Any ideas to get rid of it if it is carbon knock?

[fastTa]

First thing to do is get the car on a scanner to rule out any possible detonation, a/f ratio, or misfire issues related to the emissions/electrical system.

At this point it is just anyone's best guess, but if it is truly making a "chirping" noise, that can often times be a rocker arm with a worn pushrod seat or vice versa.

You say the pushrod is still getting oil up to the rocker? How did you measure the valve lash? Did you re-adjust the rockers? Did you look to see if all the valve locks were still seated firmly on the valve stem?

If you suspect excessive carbon buildup in the combustion chamber area that is creating hot-spot induced detonation, BG products makes the best top end cleaners/solvents. They have o2 sensor safe stuff for late model motors.