2003 3100 Woes

[Cornholeo1]

My daughter has a 2003 Grand Prix with the 3100L. She was driving and the check engine light came on and was flashing. The engine has a sharp tapping sound from the rear valve bank. Cylinder 3 has a misfire was thrown by the OBD. I have checked the compression and all cylinders range from 160 to 179 pounds. Any body seen this one before. Thank you!

 

[Steel Armadillo]

Taps all the time? Taps at idle? Taps worse at WOT?
What exactly was the trouble code?
Last time you did an ignition tune up?
Mileage?

 

[dpzelenak]

same^^
need more info to help out

 

[dsmuts]

How many miles and has the lower intake manifold gasket ever been changed?

 

[Steel Armadillo]

thread: FAIL.