O.K. Thanks Kyle,
I can eliminate that. It does have a coolant leak which does appear to be dripping off the back of the motor. If coolant is leaking into the intake, would the "miss" feel like a balance issue with the motor???

Our next step would be to R&R the intake and inspect.

 

A miss would definitely cause the engine to feel out of balance.

When you were shutting off injectors, did you just turn one off, then repeat the increase in RPM and then let off listening/feeling for a change?

 

After shutting down each individual injector, there was a noticable difference, like disconnecting the spark plug wire, so we didn't do individual testing with the throttle.

 

Ok. That really does not disprove the thought that it could be a deceleration miss.

 

While tearing down the top of the motor to start the intake job, we noticed a broken plastic fan (radiator) blade that was broken off almost completely, which attaches to the water pump. Would that make a noticable difference in the balance???

 

It is possible... Remove the fan/clutch assembly and run the engine at the point where you were experiencing the balance issue.

 

We twisted up the EGR tube. Does anyone know where to get the EGR tube (pipe) that threads into the front of the intake (near EGR) and the other side threads into the exhaust manifold in the rear of the motor. We're doing the intake gaskets and this tube is irreplaceable. The dealership wants almost $140.00 for this 3/4" metal tube that's about 20" long. The parts store say they can't get it?? Anyone know where I could get the part much cheaper????

Am I missing something here. Any help would be great.

 

WELL kYLE,
I did an intake gasket kit replacement and replaced the fan blade on the clutch and no more shake in engine.

If anyone ever has a out of balance feeling when they rev their motor, make sure you check to see whether you fan blades are all O.K. Just one of those blades was broken in half and it thru the balance of the whole engine off!

 

Good deal. If you have a PN for the EGR tube, you could check GMPartsDirect.com or Parts4Chevys.com to see what they could get it for.