What is the loud Whine when starting cold?

[redbluff]

WHen you first start the car cold I get a loud whine that then shuts off after maybe 15 seconds. Anyone know what that is?

[Amethyste]

something to do with the catalyc converter, it should stop within a minute or so... there is nothing to worry about.

[kwagar]

It has to do with the burning up of residual gases in the catylitic converter.
It is normal and is part of the low emissions sytem.

[Smartfor2guy]

It is the preheater for the catalytic converter. It only stays on for about the first 30 seconds of start up. I use this time to let the oil circulate in the engine before takeoff

[eqwalker]

Same thing observed here. Thanks for the information of exactly what it is. I was told earlier (cannot remember who on the forum) that it was an air pump purging the exhaust of unburned gases.

[Lance42]

Sounds like the high speed electric motor that drives an impeller to centrifugally induce air flow into the engine exhaust system at start-up. This is needed to pass all 50 state emissions.

[heathere3]

Thank you for asking and answering that, I was wondering what on earth it was. I knew it always shut off, but was curious!

[redbluff]

one more question. after warming up I notice what sounds like a army chopper or something tapping. Does yours sound the same? Only notice when idling and engine warmed up.

[jwight]

Lots of discussion of that here:

http://smartcarofamerica.com/forums/...hlight=tapping

[DavidV]

Originally Posted by redbluff

WHen you first start the car cold I get a loud whine that then shuts off after maybe 15 seconds. Anyone know what that is?

Girlfriend? ThankyouthankyouI'llbehereallweek

** DavidV