What's the sound? - The Unofficial BMW M5 Messageboard (m5board.com)

am5 · 13th April 2006, 05:40

Is a vacuum-like sound the car makes at start up in the morning. It last for about a minute, it winds up and then goes away.

mchin · 13th April 2006, 18:15

i believe it might be the smog pump which some refer to as a secondary air pump. I hear it in the M5 every now and then and in my E36 M3 it got really bad with age and sounded like there was a vacuum cleaner in the engine bay.

Hope this helps.

Michael

ksmith80209 · 13th April 2006, 18:25

Oh - that. It's the sound of the M5 modification bug automatically sucking all the money from your wallet. Mine activates whenever I go near the car!

mchin · 13th April 2006, 18:44

"Oh - that. It's the sound of the M5 modification bug automatically sucking all the money from your wallet. Mine activates whenever I go near the car!"

LOL --

Brother I see we share the same problem. However, if you think about it, it ain't that bad.

Happy motoring.

Michael

Beamer_usa · 13th April 2006, 22:14

Quote:

Originally Posted by mchin

i believe it might be the smog pump which some refer to as a secondary air pump. I hear it in the M5 every now and then and in my E36 M3 it got really bad with age and sounded like there was a vacuum cleaner in the engine bay.

Hope this helps.

Michael

Pardon my ignorance, but is that also known as the cold start valve?