What is that noise?

[JLDickmon]

Like CHP sez: Several things going on guys, during "Wait To Start".

Fuel pump building up pressure.

Vac pump building Vacuum. (brake booster, SOF locks, Heat/AC blend doors reseting to positions at last shut down)

Glow plug relay hum'n

ECM/PCM doing system check(s)

Chimes Chime'n

Dingers Ding'n

Unless we hear a STRANGE noise never heard before.. ? No Worries.

What Joe said.

Most likely it's the vacuum pump, as they make a godawful racket compared to the others

 

[seawolf 1]

That is what a mechanic friend of mine said it was. The ABS. He said not to be concerned. Thanks for the replies.