My air pump seems to be making more noise then it should. its a hollow burbly type of sound, not metal on metal at all. just sounds like air moving around but its loud. now i took the pump out and when i spin it by hand i can hear that sound, even when i take the diverter valve assembly off it makes the sound. occasionally i have a backfire under the hood and seems to be coming from around the air pump/diverter valve. my car is a 3.1L so the air pump just pumps air into my passenger side exhaust manifold, no cat hookup or anything. i was told that the black metal ring thats right after the rubber hose from the diverter valve that hooks up to the AIR tube on the manifold is a check valve that keeps exhaust from coming into the air pump diverter valve and pump itself. is there anyway that that check valve could have failed and lets exhaust get into the diverter valve? might this cause a random backfire every once in a while? also does it sound like my pump needs to be replaced because its making a loud pumping noise? i havent been able to find a store that has a good air pump in stock to compare too so i dunno how these things are supposed to sound. also when moving the pulley on it its not real smooth, it stops a little in certain spots. and do any of u know how to check the check valve and the diverter valve?

 

ok further inspection seems to indicate the noise is coming from the check valve ( i think?) right after where the rubber hose connects from the air pump to the tube that runs into the manifold. can these go bad? how do i check it and how much do they cost? when i disconnect the air tube hose to it its very loud and i can feel suction at it. during higher throttle it seems to be pushing air out slightly.

 

The noise from the air pump sounds normal. Yank the hose going to the check valve and blow through it. The valve should pass the air. Give the hose a suck. If you get nothing, the valve should be fine. More throttle, more air to the ports (eventually the diverter valve should switch to the cat--yank the hose and see if you can feel air).

JamesC