Something is rattling in the engine bay that I can't seem to figure out.

I checked every part of the engine, everything is tight. I checked Intercooler pipes, good. I checked the exhaust and driveline system, tight.

it rattles randomly and it gets worse when the HVAC kicks in when the A/C is on. I checked everywhere and I can't seem to find it.

 

Did you check your heatshields?

 

yup, not it.

 

Is the exhaust hitting anything? Downpipe on oilpan?

 

lose bolt somewhere, socket left in there, have you worked on your car lately and is now looking for a tool or bolt that you cannot find?

 

Negative.

It sounds like something is hitting something especially when the A/C kicks in but she I look down I don't see anything.

Having Superman's x-ray vision would definitely help in this kind of situation you know.