Silverado Making Pinging/Crackling Noise w/87 Tune

[rsonnltz]

When using the 87 octane tune, my engine is making a crackling/popping/pinging noise constantly. It is much more noticeable under acceleration, but can be heard at cruising speeds as well. It is so noticeable that passengers have asked me about the noise. I was using the diablo tune with 91 octane BP gas without any issues. As soon as I switched to the 87 tune using 87 octane BP gas the noise started. If I re-install the stock tune the sound immediately goes away. Also, I tried going back to the diablo tune with 91 octane gas and the noise went away right away. I have tried with DOD disabled and DOD enabled and still get the noise.

The vehicle is a 2007 (new body style) Silverado 1500 with the 5.3 engine. The only engine modification is an Airaid intake with an Airaid drop-in filter.

Any help as to what is going on and how I can fix it would be greatly appreciated. Thank you.

[mikel]

the cai may have leaned you out a bunch, do some loggng to see what the fuel trims look like and see if there is any KR being picked up.

Thanks

[rsonnltz]

Mike - Thank you for responding. A few things I should have mentioned. I only recently got the Airaid intake and it was making these noises prior to the intake. I tried pulling 1 degree of timing from the lower RPM range and this made no difference in the noise.

I will do some data logging. Is it ok if I post the files here so you can take a look at them?

Thank you!

[rsonnltz]

Hi Mike - I attached a log I did earlier today. You can clearly see the two times I was accelerating by the amount of knock retard. I am guessing that I need to adjust the spark advance, but I am not sure by how much. Also, are there any other adjustments I need to make? The amount of knock seems excessive, so hopefully you can help me correct this.

This was using the 87 octane tune, with the only adjustment being disabling DOD.

Thank you again for your help.

[mikel]

id start by adding fuel in the rpm range where you see KR.