Engine whine at startup

[Irv Mac]

Hello,

On cold starting, my Smart has a fairly loud, high-pitched whine. It goes away after less than a minute, as though some part were being energized. Is this normal?

Best regards,
Irv

[Dunerunner]

It is a turbine blower that purges unburned fuel from the Cat. Normal, they all do it!!

[smarticus]

It's not really the engine, it's the air injection system that helps the exhaust stay cleaner when a "cold" start takes place. You should never likely hear it for more than just a minute. If it does stay on for much longer times or all the time, call smart.

[JPaul]

Irv Mac,
Your car is just purring its happiness to see that you'll be soon driving.

[Irv Mac]

Thanks everybody,

Best regards,
Irv

[GHammerly]

It's a electrically driven centrifugal air compressor, it pumps fresh, oxygen ritch air in to the exhaust to help the catalitic converter get lit up.
Think of it like blowing air on the charcoal of your barbacue to get the fire going.
Many modern cars use the same system, my 2000 Passat 1.8T and 2001 Honda S2000 had this system.

[MB DNA]

Originally Posted by Irv Mac

Hello,

On cold starting, my Smart has a fairly loud, high-pitched whine. It goes away after less than a minute, as though some part were being energized. Is this normal?

Best regards,
Irv

To ALL the respondents to this post (and so many others) and fellow smarts:

While I often think I know it all, I am truly amazed at what I learn EVERY DAY from the posts by the community about our favorite new car!

Thanks to all who share their knowledge with the rest of us - in this case SMART KNOWLEDGE!

Have a smart day!

Tom

[NCC1701]

I'd just noticed this phenomena in the past several days and was getting curious enough to think about posting the question myself! Question answered. Thanks!