noisy 6 liter

[snorydermb]

Ive had the truck about 2 monthes when I decided to switch to synthetic motor oil now when I start the vehicle hot or cold I get a tapping or a rattleing sound from the engine you seem to hear it moore if you rev it up when the idle comes down is when you hear it.Im running mobil 1 synthetic with a wix filter im running 5 30 should I be running 10 30 if anyone else has this problem please post reply because I want to know if this is something zi should worry about

[Nice rig]

More than likely what your hearing is piston slap. Not a big deal, my 6.0 does the same thing and has 106k miles on it and is still a beast. I run 10 30 dino in mine, depends on the climate that you live in and what kind of driving you do. Look in your manual and it will state the grade of oil that is "recommended".

[TEE]

Seems the newer trucks take a tad longer to break in I guess.

My wifes 04' Sierra did it pretty good when was new but, seems to less noticable if at all right at start up.

[ChevyTech007]

I agree with Nice rig. It sounds like piston slap. Some people really get tore up about it but it will not cause any premature problems. I would use 10W-30.