Can the secondary air pump come on while driving?

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May 28, 2019 | 02:57 PM

#11

Brandon318

Thread Starter

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Joined: Apr 2019

Posts: 2,030

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From: Monterey, CA

Quote:

Originally Posted by FlyingZebra34

Hold on everyone. That sounds like your electric fan coming on. This fan is for when you are idling or running the AC. If you stop and air isn't flowing through the radiator, the temp will climb. Once you hit about 210 degrees on the thermostat the electric fan will kick on. Your SAI will never turn on after the vehicle warms up. Only on start up.

That was what I first suspected when she called this morning, but I ruled it out when she said the highest temp the Ultragauge reported was 204. Also, I don't think the electric fan produces much in the way of audible sound. It's pretty quiet/ish.

May 28, 2019 | 02:59 PM

#12

FlyingZebra34

Recovery Vehicle

Joined: Feb 2012

Posts: 1,039

Likes: 43

From: Aberdeen, Washington

Depends on the fan speed. The fan can be triggered by a myriad of things. I'd have to plug is SSD to recall everything. Mine is very audible and sounds like a jet turbine when it comes on.

May 28, 2019 | 03:48 PM

#13

Red5

Winching

Joined: Apr 2016

Posts: 524

Likes: 120

From: Chattanooga TN

Quote:

Originally Posted by FlyingZebra34

Your SAI will never turn on after the vehicle warms up. Only on start up.

I agree it's designed to come on only during a cold startup. Nevertheless, mine does come on for 5-10 seconds occasionally, long after the engine's warmed up.

May 28, 2019 | 04:07 PM

#14

Bignacio

Mudding

Joined: Apr 2018

Posts: 193

Likes: 28

From: San Clemente Calif

Mine only comes on for a couple of minutes from a cold start up. It has never kicked on while I've been driving.

May 28, 2019 | 04:32 PM

#15

jastutte

Recovery Vehicle

Joined: Jan 2011

Posts: 1,170

Likes: 300

From: StL, MO

my money's on the SAI. on both my '04's the SAI has kicked on occasionally for only a few seconds long after startup.

and, yes. it does sound like a vacuum.

May 28, 2019 | 08:20 PM

#16

CollieRover

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Joined: Mar 2014

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From: Chicago

Auxiliary fan maybe?

May 29, 2019 | 05:12 PM

#17

Discorama

Recovery Vehicle

Joined: Jun 2018

Posts: 1,235

Likes: 509

From: CA

Have never heard my SAI pump coming on when driving, only at cold start.

May 29, 2019 | 08:39 PM

#18

Best4x4

Super Moderator

Joined: Apr 2015

Posts: 7,981

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From: Beaumont, TX

My 04 doesn't do it, but I did have an 03 that would cycle on upon startup like normal, and then it "sometimes" would come on say when I exited a freeway and came to a stop on a cool morning.