I've searched this site but could find nothing that really fit. Consequently, the new thread. If I missed it, I apologize.

On cold starts only, after the engine has run for about 15 seconds, I hear a high pitched buzzing. It's very much like what a rotary saw blade sounds like when there is a piece of wood touching the spinning blade but not being pushed through. After 30 to 45 seconds, the pitch of the buzz drops quickly and disappears. It seems to be coming from the right, rear.

Any ideas, anyone?

 

Air pump...get it checked out

 

Thanks for the reply. I suspected it might be a pump of some sort; maybe fuel or air. To what or for what does the pump provide air? Is it the shocks? Maybe it pressurizes the gasoline tank? In any case, I'll certainly get it checked out.

How critical is the air pump to safe operation?

Thanks again.

 

My sounded like that...it finally crapped out. Mazda replaced it, now it's silent.

 

by the way, it's called the secondary air injection pump

 

it's located in front of the washer bottle under the strut bar.

 

ROFL, I was imaging my 450 pound cast iron monster Rockwell Unisaw crammed into the back of my 8.

 

It provides air to the CAT when it is cold to promote more rapid heating of the catalyst....and therefore better emissions. It is not critical to anything but that

 

me too