I just picked up this 2000 SS Camaro a week and a half ago.

When engine is cold, it has a noticeable "knock" that sounds like a rod knock. It is definitely NOT a valve tap...it sounds much deeper.

When engine is warmed up, the noise is all but non-existent.

Oil pressure reads 60psi at light throttle cruise
Just shy of 40psi at warm idle
50psi at cold idle.

Original owner said he used Mobil1 only.
Engine has 110,000 miles but runs fantastic.

If you rev the engine up, noise is gone...or at least I cannot hear it then.

I tried SEARCH function here and elsewhere and most engine knocks seem to be when HOT, not when COLD....

Any ideas?

 

sounds like piston slap. "normal" in a ls1 I believe.

 

Yes it's quite normal in an LS engine. They have a very short skirted aluminum piston that can rattle when cold but it expands as it warms up and the noise goes away, usually within a minute or so.

 

Again, normal for LS1s according to GM. Some do it, some don't. Do a search on "piston slap" for TONS more info. And while you're searching, there is a lot of information on engine oils, and why Mobil 1 products (especially as of late) are not optimum for the LS1. Some people have had success quieting the noise with a different oil.

 

Welcome to the LS1. Please try the fish

 

What oil do you use for your LS1?

 

I'm also wondering what is, or may be, better for this car...
Most of what I could find last night said Mobil 1

 

BTW, thanks for the replies guys...I can live with a "normal noise" that all but goes away...

 

I use synthetic oil in all of my vehicles. And since Mobil 1 no longer makes a true synthetic oil, I use Castrol Syntec and Amsoil.

 

I used Penzoil 10/30 this oil change and its ok. next oilchange im thinking Advance Q or Royal Purple

 

I have an LT1 and use Mobil 1 0w-40....from what i read this a great oil for the LSx and LTx

 

Except for the fact that in the manual in a warning bubble it says not to run any oil thicker than 30w.

 

its a perforamnce motor, thicker oil will not hurt it any, im in the road racing scene and we have 2.3L 4cylinders using 15/50 full syn for a couple of seasons they last thats a few years of every weekend running the **** out of these at almost 8grand

 

That's true.........






..........If you're running a 2.3L 4-banger

 

It's got nothing to do with whether it's a performance motor or not. It's all about oil clearances in the bearings. LSx factory oil clearances are designed for 30 weight oil and running thicker oil reduces the amount of oil per minute the flows thru that gap causing excess heat at the bearing surfaces.

And who gives 2 cants for how you abuse a 4 banger?