I have an 07 chevy 1500 classic with a little over 82,000 miles on it, in the last few days the engine has developed a "knock" in it, but the knock is only noticable between 1,500 and 3,000 rpms. Anyone have an idea of what this could be? thanks for the help

 

Is it from the bottom of the engine or top? Oil pressure look normal?

 

Hard for me to tell top or bottom, i can hear it in the front drivers side cylinder. oil pressure is normal, can hear it going down the road as well, but cant hear it below about 1,500 rpms driving or sitting still

 

How does the engine seem other than the knocking? Down on power any?

 

no loss of power, runs the same

 

I've seen cats make a knocking noise. In fact I bought a new 5.3 because I thought it was the engine knocking. Turned out to be the cat knocking.
Just a thought

 

mine did the same, it was the gas i was pumping.

 

Anyway to check the cat and ive bought gas at about 3 or 4 different places since this started. Anything to do to clear it out if it is gas induced?

 

Pop the valve cover off and rule out a spring or pushrod issue.