My friend has a 1998 Camaro Bolt on car. Developed a tapping noise the other day and we figured it was a bent pushrod. We then pulled it apart and found a very bent pushrod. Replaced the whole set with hardened pushrods and put it back together. The noise is still there. Question is..can a bent pushrod take out a lifter? The noise seems to be faster and quieter than a rod knock..seems to be in the valve train? Car still runs good..oil pressure is the same as always...power is the same. Anyway to diagnose a bad lifter without tearing it down?

 

Any Ideas? Anyone.