...at different points above 4000 RPMs. It feels like knock retard, but I am not to good at diagnosing that kind of thing. Can someone help me with some of the reasons that she's doing this, and some ideas on how to track down the problem? Thanks.

BTW, I have a new set of knock sensors for a 5.3L truck motor(LS platform)...what are the chances that they will work in an LT motor?

 

Have you scanned it to determine you are getting knock retard, or are you basing this on a SOTP guess? If you haven't scanned it, you need to use data logging software to see exactly what is happening.

The knock sensors out of LT1 engines are not fully interchangeable. Would be a real crap shoot to risk using something from a Gen 3 engine. And, the crystal used in the piezo microphone is "tuned" to specific frequencies, peculiar to the engine it is designed for. You could check to see if the resistance of the sensor is about 100kOhms.

 

SOTP, of course. I don't have any logging equipment. I am pretty sure its not a fuel flow issue, as I am fairly close to stock, and the power comes and goes. I found the tranny mount was loose (I got one full turn on the nut), so maybe that was a contributing factor. I'll go calibrate my *** and go drive it again, see what the meter says.

As for the knock sensors, I didn't know that they use Piezo Electric crystals. Thats kinda cool. I am an explosives guy, alot of rocket systems use them. Lean something new...

 

What about the knock module itself? I have heard of people "de-sensitizing" them with the soft touch of a hammer (or something of that nature). Is this a possibility? I don't know for sure where the knock is coming from, but I know that the car is running good and consistent. I get 20.5-21.5mpg average with 4:10s (M6). She doesn't burn oil, spit, sputter, hesitate, die, or any other tricks that these motors have a tendency do do sometimes, so I really think its a vibration (false) causing it...

 

Hit the knock module with a hammer to desensitize it ...... never heard that one.

You don't even know if you have knock retard. I'd find that out before trying to fix a problem that may not even exist.

There's the LT4 knock module from the 96 Corvette LT4 engine that has improved filtering, to reduce fasle knock from the Crane Gold roller rockers that were used in the engine. That's a direct swap.