6.0 LQ4 Severe Engine noise when starting cold start

[Noveske2016]

I have a 2000 Yukon XL 6.0, when starting engine cold, engine has a severe engine noise and is getting worse....let idle to warm and noise is there but quieter...take for a test drive )Hard 2-3 miles) noise goes away...no loss of power, no engine codes. I was a service writer for Chev from 99 til 2010 and remember something about the new LS engines at the time with cold start engine knock and piston skirts being to short, I have heard my fair share of them but none have sounded as bad as this is. My next step will be to remove the oil filter and cut it open to look for metal...any other ideas??

[00Silverado4x4]

Sounds like the infamous piston slap. Do a search on YouTube for GM piston slap and listen to their engines. Does it sounds like that? I know mine has it, but it goes away after warming up for a minute or so.

[sahls01gmc]

Yup, mine sounds just like that as well. It's the same sound 300,000 miles later....I still trust it!

[jimlem]

It's the same noise you heard in thousands of customer's trucks in your career. Then you told them it was operating as designed and was considered normal. Then you told them to just go away.

 

Most likely, you were cursed by hundreds of dissatisfied customers. Payback's a bitch! Best I can tell you is the same thing I was told when my new 2002 Silverado 6.0 did the same: "Oh don't worry about it. It's normal. Just live with it." BTW it turned out to be piston skirt slap. You got some real balls coming here and asking for help. Merry effing Xmas.

[Noveske2016]

Mine just seems to be a lot louder from what I remember, Im pretty sure it probably is though...

jimlem, you sound butthurt...did your mommy and daddy not play with you as a child??

[Noveske2016]

Sounds like the infamous piston slap. Do a search on YouTube for GM piston slap and listen to their engines. Does it sounds like that? I know mine has it, but it goes away after warming up for a minute or so.

Listened to the Videos, those are more of a click...mine is an actual knock, last for 10-15 minutes...does go away when at operating temp, no power loss...Im just gonna pull the filter and run it through a paint filter when it quits raining.