Cold start noise!

[chasmanz28]

Hi to all first post and ill sure it wont be my last. First off just picked up my 2006 7x for a great price and very happy thus so far. One of my questions is when i first start it up, its sounds like a tap or maybe a fuel injector sound, it does go away when the engine gets warm is this normal on the 5.3., to me the sounds seems like its comeing from undernearth the passenger side floor, or maybe that side of the engine. It has 72k BTW.

[chiller]

can you describe what you mean by a tap or injector ? like piston slap ?

[earthworm]

Originally Posted by chasmanz28

Hi to all first post and ill sure it wont be my last. First off just picked up my 2006 7x for a great price and very happy thus so far. One of my questions is when i first start it up, its sounds like a tap or maybe a fuel injector sound, it does go away when the engine gets warm is this normal on the 5.3., to me the sounds seems like its comeing from undernearth the passenger side floor, or maybe that side of the engine. It has 72k BTW.

That explains the "low" price...The OO(original owner) got rid of it due to this "noise".
But it may be nothing.
Check your oil consumption - as always .

[chasmanz28]

Originally Posted by earthworm

That explains the "low" price...The OO(original owner) got rid of it due to this "noise".
But it may be nothing.
Check your oil consumption - as always .

Ill do that thanks.

[brykcity]

The noise you are hearing is completely normal and as chiller eluded, is referred to as "piston slap". The 5.3L LH6 V8 (and most related GM V8s) have hypertonic pistons that are actually designed to expand once the engine reaches operating temperature. That would explain why the noise goes away once the engine is up to temp. I would not worry about that noise at all unless it does not subside at operating temp.

[chasmanz28]

Originally Posted by brykcity

The noise you are hearing is completely normal and as chiller eluded, is referred to as "piston slap". The 5.3L LH6 V8 (and most related GM V8s) have hypertonic pistons that are actually designed to expand once the engine reaches operating temperature. That would explain why the noise goes away once the engine is up to temp. I would not worry about that noise at all unless it does not subside at operating temp.

I had the x on the car ramps to listen to it better, it sounds like metal rubbing against something, its the craziest thing, i really dont think its coming from inside the engine at all, maybe the flywheel, or a sticking valve from the transmission. It doesnt do it all the time but when it does i can hear it.