Rotary Rasp

iTrader: (2)

It's 10am in the morning and about 60F outside. I walk outside get in my car and start it. What do I hear "weeeeeeeeeeeeeeeeeeeezzzzzzzzzzzzzzzzzzzzzzzz z" for about 1 minute. It has been this way for as long as I can remember, but it seems pretty damn loud. Is that normal?

For those of you who don't know, the secondary air injection pump circulates warm air from the exhaust into the intake to help meet emissions during cold starts.

ucfracerx8

Yep, mine has always done it. The colder it is when it is first started, the longer it seems to run for. I have not timed it to see if this is actually true, or if it simply runs for a set amount of time at Start-up. Maybe Zoom or RotaryGod knows for sure. I typically wait until it stops to move the car, I use the wheeezzz stop as my warm up guide, once it shuts off, I keep the RPMs under 4k until the temp is up to the middle and then drive normally.

MazdaManiac

iTrader: (3)

^^ This is exactly my warm-up schedule and what I recommend to every one.
The amount of time the pump runs does change according to temp, though I haven't seen any data in the shop manual to indicate what criteria the PCM uses to decide how long it should run, if at all.
30 seconds is typical.

xrider01

i don't think i've ever heard that. i always hear the clutch over everything else.

MazdaManiac

iTrader: (3)

It sounds like a mini vacuum cleaner. Next time your car is stone-cold, pop the hood before you start it and get out and listen to the device just in front of the windscreen washer bottle.

Rotary Rasp

iTrader: (2)

Makes the car sound like it has a jet engine under the hood.

xrider01

lol....i'll do that then. i gotta add a quart of oil today anyways, so i'll have the hood open

Imidazole

My old Camaro had the same exactl air pump sound.

RenKat

The air injection pump puts fresh air to the Cat until the Cat reaches light off temp.