[kericks]

When I first start my '07 Tundra w/ 5.7L engine, for about 15-20 seconds there is a decidely high pitch, motor sound coming from (I think) the passenger side of the engine compartment. It actuallys sounds kind of neat and high tech, but I don't know what it is. I only hear it on startup as well. You can hear the motor wind down as it shuts off too. I doesn't sound like a fuel pump either. Could it be part of that fancy Toyota "Acoustically tuned" air intake? Any ideas?
K

 

[blackgts2002]

i know what you are talking about. does it when it starts up. almost sounds like a Blow off valve (obviously it is not). I thought it might be the A/C compressor.

 

[grpweld]

Pretty sure it's the fan clutch

 

[emerson]

According to page 229 of the owner's manual it is the sound of the vehicle stability control system doing a self-test on start-up of the engine.:tu:

 

[kericks]

I'll buy the stability control answer!
Not a fuel pump or fan clutch sound.
Thanks!