Kind of looking for clarity here, over the last 2 days, a tick has been coming from my engine, 305 Lb9 TPI, and I guessed it came from the #7 cylinder cause you can clearly hear it from the inside. Its completely consistant with RPM, cant hear it when idling. When I unplug the #7 fuel injector, tick goes away...whats causing it?

 

pushrod motor

ticking sound comes on suddenly

stuck lifter?

 

Motors been rebuilt but we reused the lifters, Im hoping its an easy fix, I dont want to take off the manifold again

 

might only be a blown exhaust gasket-that would stop ticking when injector unplugged

 

How could I determine a bad gasket? I just took the valve cover off and the push rods are fine, and there isnt any excessive play in the rocker arms.

 

AUTOMOTIVE STETHOSCOPE is cheap to come by, and can help you listen to specific components during troubleshooting

 

I think you will need to turn the motor over slowly one revolution, and observe the rocker arms for excess clearance at various intervals to conclude that there are no lifter problems. This test can be further skewed by the fact that a "stuck lifter" can be stuck intermittently, and fine at other times.

You should do this test when the motor is fully warmed, and only recently turned-off. Otherwise the lifter could be stuck from just being cold, and the pressure inside the lifter could bleed down if the car has been sitting for any length of time.

 

gave it a few revolutins by hand, seems good. I just hope cams not getting chewed up

 

OK

We'll say the lifter is good.

Cylinder knocks when fuel is provided.

Weak spark and/or fouled valve causes detonation?

Does the plug in the offending cylinder have sooty deposit?

Bad plug wire causing weak spark?

 

Pulled spark plug, looks good. wires arent leaking spark...looks like a trip to the shop is in order...