Hi everyone. New here. I have an 02 silverado lt 1500 5.3 111*** miles with a knock/tick. I can hear it when driving between 25-35mph at abt 1500rpm. I think it's on right side. I can't tell if it's a lifter, rod, crank bearing. Driving me nuts, I like to see if I can do something before it gets worse.

So a couple of weeks ago I went to my mechanic he suggested oil stabilizer. Wow that was a bad idea. Everything knocked bad. So I quickly went home changed oil AGAIN, week/days later I put in seafoam bc thing of not getting all the stabilizer out. Which I was Glad I did it bc more of it came out. Couple days ago I did a engine flush. That seemed to help alittle, not as bad of knock/tick. But when I am in driveway I have wife idle engine at 1500rpm +/- no knock or tick. What gives???

Do I try another flush? Pull spark plugs on passenger side. I always change oil (high milage) at 3000 mi or so. Also in summer it sits a lot bc I ride my bike. Could there be sludge built up? I read something abt other people saying "o" ring on the oil pump pick up tube. IDk. I know it's not piston slap. That's loud.

 

It might be piston slap. I recall reading about how the 5.3 liter of that era had lots of issues with engine noises like that, while still brand new. Too bad Chevy didn't just stick with the 350 CI, or slap a 327 CI in that pickup, for that matter. Might try the old "1 quart of automatic transmission in the engine", fluid flush, but I highly doubt that's gonna help. Are you the original owner of the vehicle?

 

I had to have two pistons replaced in my 2000 5.3. If the "tick" is loud, might be piston, I'd suspect lifter since you've flushed the oil out. If it where me, I'd try to pinpoint the location, if it's upper I'd either replace the lifters, or at least pull one at a time, clean them in diesel, then let set in fresh oil you are using, then re-install. You have to do them individual or make sure you re-install them the way they came out.

 

What is your oil pressure at highway speed and the oil pressure at idle. What is your oil weight and is it Synthetic or conventional. Normally, if you heard the tick on a cold start up I would suggest not to worry. The fact that it does not go away after warming up is a bit troubling. There is a Chevy bulletin (15-06-01-002C) for more modern 5.3 liter engines with Active Fuel Management (AFM) that talks about replacing the lifters if you can't get rid of the problem. However, your engine is not one of these. One thing Chev is doing these days is changing their oil requirements to fully synthetic 5W-30 oil. It has the Dexos designation. For instance Mobil1 makes a version. You might want to change your oil to this if you are not already doing it. Was that oil additive pretty thick? If so, it looks like the engine and lifters want a thinner oil, not thicker. From what already read, replacing the lifters is pretty straight forward, but if the cam is damaged it gets quite a bit more expensive.

SD