Gentlemen,

This is crazy, but the engine hoots when shutting down or sometimes when reving over 4000 rpm. I think it is in the emisions valving somewhere.

Does anyone have a clue as to where to look?

Let me know if you have any ideas!

Best regards,
THC

 

Its the airpump on the passenger side of the engine. The sound you hear is it pumping crazy air that is supposed to enter the cat. Mine did the same thing. You can get a kit to eliminate the pump, probably a good idea.

 

Try disabling the shutter valve. Here's an old thread with some good info on that.

 

Thanks guys. Now I know what to work on.
THC

 

To test the shutter or (coasting) valve, pop off the stock aircleaner top, remove the eliment,there is a hole no bigger then a pensil, use your finger to block it off,,no vacum = shutter valve bad, vacum = something else.
now this test is for 12a engines (california)
The hose from the shutter valve to the underside of the aircleaner canister can be blocked off with a bolt.



















=

 

I think Mazda refers to that as "honking"

 

Dave at KDR mentioned to me that the shutter valve makes the rear rotor run lean. Should it be put back on when getting it smog tested or doesn't it matter?

 

I thought it was the other way around..... Vacuum meant it was bad, no vacuum meant it was good (at Idle)

Jeff

 

Woa..I took the big one off on the right side to see what it would sound like..you could call the ducks home with that hose off!

 

Yeah,, your right, it is the other way around.. I've got a brand new mazda shutter valve for 12a extra that i'll sell.
thanks for the heads up. man.

 

Do you clamp down on the hose when the car is idleing or when it's off? Is it better to have the shutter valve open or closed? If open, how do I get it to stay open so I can put the clamp on and vice versa? Thanks.

 

Clamp it when the car is off.