Extremely high knock counts.

[tayto]

exhaust hitting frame, exhaust manifold leaks, faulty pcm, faulty calpack (try reseating), faulty knock sensor, faulty knock sensor wiring, timing chain loose hitting timing cover, worn out/noisy vakve train

once you cover all bases, you can try installing a brass 45* or 90* fitting between the knock sensor and block, this will "detune" the sensor slightly. if your engine is "stock" I would not be pulling timing from the stock calibration. you have a mechanical problem, not software.

 

[Schurkey]

exhaust hitting frame, exhaust manifold leaks, faulty pcm, faulty calpack (try reseating), faulty knock sensor, faulty knock sensor wiring, timing chain loose hitting timing cover, worn out/noisy vakve train

...bearing knocks, over-tightened knock sensor, incorrect knock sensor, wiring harness picking up electrical "noise" from some other component.

 

[tayto]

over tightend knock sensor is a good one. whats the torque for it like 14 ft-lbs?

here's another good one: when i built my first vortec headed 350 w/ tbi i had crazy knock counts. went 2 steps colder on the plugs and the counts went to virtually nothing. had only touched the VE tables, hadn't even messed with spark tables at this point.

 

[PlayingWithTBI]

went 2 steps colder on the plugs and the counts went to virtually nothing. had only touched the VE tables, hadn't even messed with spark tables at this point.

Yeah, I'm running colder plugs but, I also have aggressive SA and VE tables running a WBO2, with very few KCs. In this case, I'm leaning towards something mechanical.

 

[tayto]

yes I agree. for something stock my money is going to be on exhaust or internal engine noise

 

[Sabinoerc]

I had similar burst of extremely high knock counts on my 93 5.7l once. In my case it turned out to be a bad knock sensor.

 

[RI Chevy guy]

Take a look at your temp sensors, I has some issues with mine and it caused similar issues (though not as extreme). If it thinks it's running too hot it will retard timing and create a knock