Well, me and my uncle have the same truck, same engine, just mine is an 02, and his is an 01. We have the exact same issue too, when we start the truck after it has been sitting for a while. It sounds like a diesel. Literally.

We have both gone to different mechanics, and got different diagnostics from each of them.

One said it as due to the aluminum heads needed to expand from cold to warm.

One said it as lifter tap.

One said it a valve limiter put in there from GM, so you can't rev the engine high when cold.

One said we need to be running 91 or higher gas.


Anyone else have this problem, or any ideas for me?

Thanks






**there is only one true love in my life... and my girlfriend has learned to live with it**

Do the trucks run fine?

If so whats the big deal, just hate the sound?






How many steps to heaven, Doc?
...Ah, metaphysics.

ya, they run fine. For now. Who knows what could come in the future. A gas engine should not sound like a diesel.





**there is only one true love in my life... and my girlfriend has learned to live with it**

Ever been around an Ecotec engine when it starts up in the cold winter mornings?
It's pretty noisy too.
Later
Redrider02


"big boom big boom"-Adam Savage. "quack damn you"-Jamie Hyneman "mythbusters"

I thought back in the day there was a TSB about cold startup, where it was piston slap. I could ask my brother, he would remember better than I can. Once it warmed up, the tolerances got better and the noise went away.

O noes!

If it goes away once its warm, its the LS engine wrist pin issue. All 5 guys that I work with that have 5.3/6.0 have the noise. There is a fix, but its expensive if you are out of warranty. New crank, rods, pistons from the newer engines.

As fat as those other "mechanics", I want to know what they're smoking and why aren't they sharing, they probably still tell people that if you mix green antifreexe and dexcool that it hardens like concrete, and that dexcool eats aluminum.



Lifes too short to drink cheap beer.

its piston slap. Nothing wrong with the engine. All LS based engines do this to some degree. GM has a couple of TSBs about this. New rotating assembly will not resolve this issue. The new ones still did it when I left the dealer in Aug.

Keep driving, dont worry about it.

Invest in a remote starter. By the time your ready to drive it, the engine will already be warmed up

They were all dealer mechanics too, that's funny part. Not my everyday mechanic.

I do usually give it a good 20-30 minute warm up in the morning before work, I have a long drive, no point in freezing for half of it while the truck warms up. So, it is not really and issue there.

Still, even if it sits for an hour, it will do it again.





**there is only one true love in my life... and my girlfriend has learned to live with it**

http://www.pistonslap.com/index.html

My 3100 runs like a tank when cold. As soon as it warms up, it runs like a charm.

Look at the bright side. If engines are made to run with @!#$ty tolerances in the build, they will likely still run just as well when they are all worn out.

Chasing an engine noise is always an expensive proposition. My best advice is to drive it until something breaks.

And then get this crate engine from GMPP. If it's made at the real shop, it'll be a tight setup.