5.3l Engine Knock On Accel.

[Ridgeback1]

My 08' SLT 5.3L 4x4 with 64K has been knocking while under full acceleration(?). I use major brand gas, mixing it up between 87 & 93 Octane. K&N air filter is only engine mods. - and it's clean. Anyone know what could be causing this..? Known problem with this (aluminum block) version of this engine?

 

Thanks!

[txab]

Could have some carbon build-up. Have you checked for any codes?

[TimoSLT]

i may not be a Gm tech but with what i have experienced when i get a little bit of a knock in the engine it means my oil is nearing the end of it's service life.

 

so when was the last time you changed your oil??

[desrtrat]

Could have some carbon build-up.

there is a difference between a knock and a ping. running a lot of 91+ gas will carbon up a motor quicker than 87 due to it's slower burn. at 64k i would do a Sea foam or BG upper engine treatment. also you may have a injector a little dirty and leaning out a cylinder just enough to cause a lean fuel mixture.

 

good luck

[Ridgeback1]

Thanks, I'll see about the codes and carbon. Oil is pretty fresh - synthetic.

[gmtech4]

you have 5 yr powertrain warranty