2011 5.3 loud knocking

[Mrblazier]

I have a loud knocking, not ticking, noise with a little bit of  squeal coming from the bottom of engine. It does not go away after warming up. My fuel economy has gotten worse and have a intermittent lack of power during acceleration. There are no codes popping up. Any ideas of what it could be. I change my oil every 2000 to 3500 miles due to active cylinder management and loss of oil.

[Jsdirt]

Any time I've heard a squeal with any engine that wasn't belt accessory related, it was an air leak - usually combustion leaking, as in a blown head gasket. With newer GM cars, I've heard squeals from piss-poorly engineered PCV systems pressurizing the crankcase - that will cause air to blow across and through seals, which they're not designed to handle.

 

Something like this, first thing I'd do is remove the belt, and fire it up to see if the noise remains. Easy 5 minute procedure there. But, any kind of knocking in these engines, especially over 100k miles, and I'd be making plans for a new long block. Thank GM for that one. 300k mile engines weren't making them any money, so they built the '07-up engines with low bidder garbage.