I know it sounds weird but I don't know how else to explain it. I think it all started when I installed my lt's a few years back. Whenever I turn the ignition off (doesn't matter if the car is running or not), I hear the air pump make a quick whining noise (I think this is normal), but then I hear what sounds like air going through the headers. Sometimes the noise is quiet and you can't tell, but other times its really loud and seriously sounds like someone is blowing an air horn or trumpet. Anyone have any ideas about this bizarre problem?

 

Why don't try disconnecting the air pump so it does not run and see if the noise goes away?

 

I suspect the noise is caused by the check valve in the air system at the headers slowly opening.

 

I'm going to try that tonight

Which part is this exactly?

Thanks alot guys.

 

Haha Sorry, but I laughed out loud when I read this.

 

 

Thanks a lot man.