I have an 03 Chevy pickup 4.8 liter vortec. It has a loud tic tic tic noise when cold. After it reaches full operating temp it goes away. I believe it is a lifter noise. It is noticeably loud.
Will it hurt to keep running it? what's the cure? Any ideas?

thanks, wingnut

no sweat. its normal. just keep that oil changed regularly. if it gets worse, you could have someone try to decarbon the motor.. but from my experience, most all those do that lifter tick when they are cold.

mine did it when i didnt use the right oil, be sure to use what it says in the owners manuel.

It is annoying.

5w30. dont let them put 10w30 in your truck. i have seen some ford motors burn up crank bearings using the 10w30.

Its carbon on the pistons causing the noise. GM has a technical service bulletin regarding this issue. However annoying it is-- its normal. You gain get rid of the noise by removing the spark plugs, filling each cylinder with GM top engine cleaner, let soak overnight, spin the engine over to remove solvent, replace the plugs and drive it. Your noise will be gone for about 20-30k miles- depending on how frequently you change your oil

Yes, I am using the correct oil 5w-30. Change it myself.
Just so I can understand what is going on, how does excess carbon cause a lifter noise? is the carbon buildup causing the valves to stick? or is it the noise of the piston slapping the carbon buildup at the top of the stroke? thanks

carbon on the piston is contacting the cylinder head. I know it sounds like lifter noise but its not. Wait until this winter when its about 40 degrees out and it will sound like a rod knock. I've seen it so many time i cant count.In 1999 when the 5.3 was first introduced, we were actually installing new lifters per GM, we were also cleaning the heads and piston tops before reassy.It was the cleaning, not the lifters that solved the problem. Then for the next 2 yrs we were doing what i described before, with the top engine clean, then GM decided it was normal noise and would in no way affect the longevity or durability of the engine and would no longer perform the service under warranty-- see TSB 01-06-01-028A - It really pissed off a lot of customers

I was one of those pissed off guys that knock drove me crazy but I was told that year model had roller rockers and that was normal and after a few min it would stop it did but man you talk about mad but I drove that truck 180,000 without any problems.

thanks for the info. can B-12 be used to decarbonize, or does it need to be the GM stuff?

this is why i like my ford right now.

Any name brand top engine cleaner should work.

Might try adding some Seafoam in with the gas every other fill up. Then follow the routine schedule on the can. Just a thought.

MY WORK TRUCK IS A 2000 CHEVY 5.3 AND MY KNOCK WAS BAD, THEN I FOUND NEEDLE BEARINGS IN THE OIL DRAIN PLUG, IN TURN HAVING TO HAVE THE VALVE TRAIN REPLACED NEVER LEFT ME STRANDED THOUGH

thanks for all the help.

get a can of amsoil powerfoam, that will decarb your top end in a breeze

My 2001 started that also. I think also it alot to do with the gas. the crappy corn squeezings.Might want to change fuel filter also if you have one. Traded mine in last year got the 5.3.real happy with it.

OK, I ran some B-12 in the gas for a few days. . . .no change.
Then, Marvel Mystery oil in the gas as directed. Drove it about 35 miles and parked it. The next morning the knock was gone and has not come back. Thanks for all the help. It sounded just like a stuck lifter but it sure must have been a little carbon. Does anyone else use this stuff? It seems strange that you can add it to the gas or oil.