Need help- knocking noise coming from Engine

[harrycalahan]

If it was a legit knock, then it’s your compressor knocking and self destructing. Not good but beats having a real rod knock.

 

[woodstock]

Had a harmonic balancer knock once

 

[YOTESHOOTER]

Should it be the a/c compressor and it destructs, the complete system will need to be flushed and condenser, and the evaporator also, be sure to refrigerant oil in the condenser, and make sure the compressor has oil in it before ever turning the a/c system on.

Before starting the system check the compressor oil level, if it is where it is suppose to be,
turn the compressor pulley 30-40 complete turns to make sure the refrigerant oil is not on top of the compressor pistons to prevent any damage from happening.

just a simple suggestion to consider...

 

[Tusker6N]

Due to the small passages in modern condensers, they can not be flushed, it will need to be replaced.

 

[3clicks_Off]

hopefully it's the idle pulley. had this happen before

Check this with belt off. If it feels rough spinning, replace.
Check ac clutch bearing same way while belt is off.

After though edit:
Just to release some possible liability issues.....Turn Off the engine first!

 

[8675309]

try listening to the component with a stethoscope
or a screwdriver first but dont get hurt

 

[Kahrnut]

or a screwdriver first but dont get hurt

Vodka and orange juice never hurt anyone.

 

[hops2899]

Had a harmonic balancer knock once

I have witnessed this in the past as well, worth looking into.

 

[Ken Ford]

Had transmission flex plate bolts come loose, sounds just like rod(s) knocking. Some mechanics will tell you it needs a complete rebuild.

 

[hikingthehills]

Release the midgets from under the hood and they'll quit knocking.