Lifter Adjustment

mtnflyguy · July 16, 2009

I own a 2001 2500HD with the 6.0 engine. This weekend I will be replacing the knock sensors. While I had it opened up I thought I would adjust the lifters. When I start the engine I get a little knock or a tap for the first few minutes each morning. After about a minute or so it stops and I don't hear it for the rest of the day. I have been told that this is the lifters that need adjusting. I am just wondering if you guys agree and if so how difficult is it to adjust them? Thanks!!

496SS · July 17, 2009

I own a 2001 2500HD with the 6.0 engine. This weekend I will be replacing the knock sensors. While I had it opened up I thought I would adjust the lifters. When I start the engine I get a little knock or a tap for the first few minutes each morning. After about a minute or so it stops and I don't hear it for the rest of the day. I have been told that this is the lifters that need adjusting. I am just wondering if you guys agree and if so how difficult is it to adjust them? Thanks!!

I believe they are non-adjustable. Many of the LS engines have this rattle on start up. Suposidly it is piston slap at least in the LS1. Information I have found is that it doesn't hurt anything and I just reciently read a post where the owner switched to Penzoil Platinum and it went away.

mtnflyguy · July 18, 2009

hmmm??? Maybe I will switch to a synthetic and see where that takes me. Thanks for the tip!

clm7214 · July 18, 2009

I own a 2001 2500HD with the 6.0 engine. This weekend I will be replacing the knock sensors. While I had it opened up I thought I would adjust the lifters. When I start the engine I get a little knock or a tap for the first few minutes each morning. After about a minute or so it stops and I don't hear it for the rest of the day. I have been told that this is the lifters that need adjusting. I am just wondering if you guys agree and if so how difficult is it to adjust them? Thanks!!

I suppose you mean rockers, and not lifters. The rockers are non adjustable. You can however take off the rockers and check for any excessive wear on the rockers and pushrods, then re-torque to spec. I did this on my 6.0 and didnt find anything and it didnt make it any quieter. My 6.0 at 150,000 miles is louder than any duramax ive driven. Most of the ticking coming from the valve cover area is from the injectors and fuel rails anyhow.

What you're hearing at startup is piston slap thanks to the short shirt LS pistons. Just run a good full synthetic oil. The LQ4 engine is why i'm buying a new truck, i cant take it anymore.