04 Silverado Knocking At Startup

[jrh_67]

First i would like to say hello!

 

My problem is I just bought a 2004 silverado with the 5.3 engine with 57,000 miles on it and everything seemed fine. I changed the oil for the first time last weekend and used royal purple 5w30 with a k&n oil filter. When i first cranked the truck after changing the oil i noticed a slight knocking sound that went away after a few seconds and i thought it must be because the oil had to get circulated through the engine. Now after a couple of days and really listening for it i notice it does this every time I start it...knock knock knock for a min or so, even on warm starts like going into the convienance store or something. It is worse on cold starts but is still there slightly on warm ones also. Since I just bought the truck I'm not sure if it was doing this before i changed the oil and i just didn't notice it because you really can't hear it in the cab. Should I change back to dino oil? is there a certain oil filter these trucks like? The truck runs great with good oil pressure but i'm just concerned because i don't want to damage my engine.........

 

Thanks in advance.

[txab]

Cold start knock is pretty common on these engines. Mine does it, but goes away quickly. I'm running 10w30.

[2000DV4.8]

Do a search on here for "cold start knock" or "piston slap", this is a very common (non)issue with these motors. My truck's got over 180k, has knocked as long as I've had it (about 30k), and it hasn't gotten any worse. Unless you have a really severe case, you have nothing to worry about.

[jrh_67]

Thanks for the responses! As long as it doesn't damage the engine i can deal with it. Has anyone had any luck stopping it by using different oils or filters?

[Silverado4x4]

Your best bet would be to get rid of the k&n oil filter and go to a factory ac oil filter, I have heard this happening before with after market oil filters. I dont think your hearing piston slap because you say it happens everytime you start the truck and everything was fine before.

[jrh_67]

So when i try the ac delco filter should i leave the 5w30 royal purple oil in or try something else?

[txab]

So when i try the ac delco filter should i leave the 5w30 royal purple oil in or try something else?

 

Run it with the RP. you could always try 10w30 next time