engine noise at high rpm

[banditmotor]

I need a little help. I have 98 Z28 6 speed. When I run the engine under full throttle into the high rpms I get a knocking noise. It seems to come from the left side of the engine. The car also seems to lacking power. Occasionaly when I hold the throttle steady there seems to be a barely perceptable variance in the power.

I replaced the waterpump about 20k miles ago.

Any help would be appreciated.

Sean

[nhraformula]

sounds like pinging, better known as knock retard.
youre a/f ratio maybe off.

[banditmotor]

how do i adjust my air/fuel mixture?

[SeVeReDiStOrTiOn]

a tune......either on a dyno or canned

[Liquifire]

I need a little help. I have 98 Z28 6 speed. When I run the engine under full throttle into the high rpms I get a knocking noise. It seems to come from the left side of the engine. The car also seems to lacking power. Occasionaly when I hold the throttle steady there seems to be a barely perceptable variance in the power.

I replaced the waterpump about 20k miles ago.

Any help would be appreciated.

Sean
I seriously doubt that the water pump has anything to do with it.......unless you are running at 300 degrees.........do you have any mod's done to the car or stock?

[banditmotor]

There are no mods to the engine, borla exaust and K&N air filter are all that has been changed. I am beginning to think the noise may be coming from the clutch assembly. Possible damage to the clutch or fly wheel causing the noise. If anyone has an opinion, let me know.

Thanks for all the help so far.

[keliente]

Sounds like spark knock to me. High rpm's, lack of power, etc. Get it on a dyno and have a tuner work with you to achieve the correct air/fuel ratio. Or perhaps something mechanical could be causing the poor a/f ratio, such as oil consumption, etc.