Spark Knock/Pinging Issues im Having

[HotRodV6]

Ok, my 03 Silverado 5.3L vin T has just over 59K miles, and runs pretty strong for a bone stock truck. But ive noticed in the last month or so that when i get on it hard you can hear some spark knock, especially in the 3500-4000+ RPM range. Well i have only been running reg ole 87 in it since i bought it, and have ran one can of seafoam in the gas tank thur it, and didnt really notice any differance, but now that i think about it the pinging started after the seafoam.

Well this last tank i filled up with 89 to see if it would make any differance, and i have alittle over 100 miles on this tank so far, and used about 1/4 of a tank and it doesnt seem to be any better.

Any ideas as to why im having this problem?

Thanks

[ff_jeff]

Get a tune!!! Oh Mine did that when i first got it, (I bet This gets some negative reactions but) I ran 100percent acetone, 2 oz of acetone to 10 gallons of 87 and I never had the problem agian. Maybe a coeenkydeenk but Who knows. Now i run 93 with my tune... no probs

[HotRodV6]

yeah i want to get it tuned, but my money tree is getting pretty thin this time of year.

And with the low CR of these engines you shouldnt need the higher octane gas, but maybe next fill up ill put 93 in it and see if it makes a differance.

[farmtruc]

Maybe it's running a little too lean, what's the a/f ratio?
During the winter, our trucks run stronger and if the a/f ratio is on the edge, it may be running lean.

good luck,
allen