What is the noise I hear when first starting the car?

Probably a stupid question here, but my curiosity compels me to ask. When I first start my car in the morning or after an extended amount of time (ie after work) the engine starts and sounds normal however there is what sounds like a fan spinning up that lasts for about 10-15 seconds then it shuts off and I hear a click of a relay in the dash. I'm curious what this is. Anyone?

Views: 75

Reply to This

Replies to This Discussion

The dealer rep that ran me through the new owner's training stated that I would hear the coolant pressurization pump run for half a minute or so when the cold engine first starts. Once the engine is warmed up and running, the coolant will flow between the radiator & engine without the pump.
It only happens when I start the car cold so, that seems to fit the circumstances. I am just one of those people that likes to know everything that is going on with my car, not to mention, everything I can about it as well.

Thanks for the info.
Seamas, thanks for asking; Cliff for answering! I heard this, too, on our new smart and was wondering, but never thought to ask!
I had to ask, it was driving me nuts trying to guess what it was lol
Cliff's dealer gets style points for creativity, but you are not hearing a "coolant pressurization pump." The whirring sound you hear during a cold start is from the secondary air injection pump. It's designed to reduce tailpipe pollutants when the engine is running cold, the fuel mixture is rich, and the engine is putting out maximum garbage. It's one more way your smart is designed to be a "green" vehicle.

This topic was banged around a lot about a year or so ago, shortly after the car came on the market. Here is what smart says about it:

"Engine 132 is fitted with a secondary air injection pump (electric air pump), which injects additional fresh air in order to reduce exhaust gas emissions after a cold start and to accelerate the warming of the catalytic converter to its reaction temperature.

"The necessary air is injected into the exhaust ports in the cylinder head by the secondary air injection pump via the combination valve.

"The secondary air injection pump switchover valve is supplied with vacuum from the vacuum reservoir at the intake manifold via a check valve. When actuated, the secondary air injection pump switchover valve releases vacuum to the combination valve. This opens and the air injected by the secondary air injection pump passes through to the exhaust ports in the cylinder head.

"The injected air reacts with the hot exhaust gases in the outlet port. The carbon monoxide (CO) and hydrocarbon (HC) are oxidized. This "afterburning" process increases the exhaust temperature and reduces pollutants.

"The duration of secondary air injection is dependent on the coolant temperature.

"The secondary air injection pump is only actuated at a coolant temperature of 45 °F to 97 °F (7 °C to 36 °C) and for a maximum duration of 33 seconds."
Well, I'm blown away;-) Thanks for setting me straight!
Ditto! lol
I thought it was the turbo charger firing up, or the afterburner...LOL THanks, that was the first thing I thought this morning! prepare to takeoff!

Seumas said:
Ditto! lol
Well that Explains why I have that Kompressor Emblem on the back of mine...hehehe

Thanks JackB...Someone else suggests it was a clutch disc problem,which seemed doubtful because I only have 2,000 miles on my Smart...
Brabus007 said:
Well that Explains why I have that Kompressor Emblem on the back of mine...hehehe


What type of exhaust do you have there?
~$3.53 each~if you do this "You'll Love Them"~one of the Best Low Cost Easiest Mods you will ever do to your Smart~

They are a Perfect (snug)(just press & wiggle them in by hand) Fit...<:-)) I Dremeled out a center hole ~ Taped around the end that slips into the 3" tube (its just the right size already) and painted them Silver (I used "Rust-Oleum" paint~it worked good) after scrubbing them down with a "SOS" pad to make sure that they were Clean & free of any mold release resido ~ I drilled a little hole for a little screw in the 3" Tube just to make sure they would not back out...
NOTE: I also Bought a Spray Can of Black Barbecue HiTemp to spray the Muffler Shield ~ the little Exhaust Tip ~ and the visible Silver from the Rear lower part of the Tranny Pumpkin ~ All that Silver Crap under there just disappears when L00KING from 20ft. behind (looks like My Picture) Naturally I cleaned it up good before spraying, and I shielded anything I didn't want painted with Tape & News Paper before spraying...
http://www.smartcarofamerica.com/forums/f25/save-our-tubes-de-dion-...

3" Atrium Grate
http://www.lowes.com/lowes/lkn?action=productDetail&productId=1...

Seumas said:
Brabus007 said:
Well that Explains why I have that Kompressor Emblem on the back of mine...hehehe


What type of exhaust do you have there?

Reply to Discussion

RSS

find a

smart center

go

Photos

Loading…
  • Add Photos
  • View All

Videos

  • Add Videos
  • View All

© 2014   Mercedes-Benz USA, LLC.

Badges  |  Report an Issue  |  Terms of Service