My Tahoe has some pretty wicked piston slap when cold. Well, I was told it was piston slap, but it almost sounds like rod knock; but it goes away when warm. I bought the truck like this and I am about to be ready for my first oil change. Is there some specific oil I should use to quieten it down. Would a higher or lower weight oil help? The previous owner said he ran synthetic, but didnt specify what oil.

What oil?
What about additives?

Other than the noise on startup, it still runs great...

School me please..

 

I run mobil 1 synthetic. I have found that running is 0-30 Over a 10 - 30 Seems to help

 

Stick with 5w30, because it will still happen with what ever oil you put in, just let the truck warm up a little bit when it's cold, the warmer the engine gets the less you hear it when you first start driving.

 

That knock was pretty specific to 2000 - 2003 5.3 motors. It knocked like hell cold and then would go away. Mine started at 10,000 miles and finally went away about 60,000. I even wrote chevy a letter and they told me it would not be a recall, then they sent me a document to reasure me the motor was fine and they would back it for 100,000 miles. It never gave me a bit of trouble. The motor is cammed with Zo6 heads and in a Jeep with over 95,000 miles and going strong.


Vid:
http://www.youtube.com/watch?v=OBWEY...e=channel_page