Sgtinarms

Hello,

I have a 2002 Chevy Silverado 1500 with the 5.3L. The truck has 198k miles on it and still runs strong. Lately it has developed a knocking noise at the 1100-1300 RPM range. The noise goes away when I apply more throttle and get it out of that RPM range. No metal in the oil, Fresh oil Change, still has good power. I feel like it might be a stuck lifter/loose lifter, but I wanted to get a second opinion. Do any of you have an idea of what it could be? thank you for your time and help.

MountainTodd

I'm not a professional mechanic by any means, but my experience with sticky lifters is that it's more of a tapping sound. It also usually taps just after starting the vehicle, then goes away if you are lucky.

rockin5b

I know this is "old business" but, here is a little of my experience with my 2002 Chevy Silverado LS Z71. I just recently changed out my knock sensors. I had a trouble code that popped PO332. It is, from what I have researched, one of the top most common things that need fixed on this year of Silverado. I have had that same knock on my truck for years and was told that it is common and "not to worry" thing when I first heard it on my truck. I am the second owner of this truck and bought it with 64,000 on it April 2007. I have heard this knock for almost the entire time I have owned it. It always started out in the beginning of the "cold start" and always went away. I have the common habit of starting my truck and letting the engine get a little "warmed" before scooting to my next point with my pick-up. I have been at least 95-98% accurate with that habit the entire time I have had the truck. I put off replacing my knock sensors for about 6-12 months...no, I know, not a good thing... Anyways since I had replaced those sensors I have had absolutely no knocking what so ever since the replacement. Hopefully this helps someone.

2001 chevy silverado

#1 KNOCKING NOISES ARE IMFAMOUSLY HARD TO CHASE DOWN - EVEN FOOLS 9/10 MECHANICS

make sure where the knock is !!!

sounds bounce around metal blocks like you wouldn't BELIEVE. a deep thud knock sounding like an crank case noise could EASILY be a power steering pump noise. easily.

put a long screw driver to your ear, find out where sound is loudest. and remember: even that won't always tell you for sure (loudest doesn't always mean you found the source)

"only everything on the drive belt and behind it might be responsible for that noise"

2001 chevy silverado

#2 WHENEVER YOU HEAR ANY KNOCKINIG OR TAPPING. check to make sure all your lugnuts are tight

even safety inspectors (who remove wheels) are famous for sometimes forgetting to tighten them (or doing it wrong)

you could loose a wheel - always whenever you hear noises if it sounds like under the dash or not - always check your lugnuts

2001 chevy silverado

you may need to run it on a car lift to isolate the noise. if that doesn't work - then you'd be thinking "ah, bearing or something"

you know how to check bearing play i assume? I think your truck has sealed bearings so i'm not guessing loose spindle - but i'm unsure about 4wd models