Strange Noise at startup

I have a '10 crewcab trd sport longbed. It makes a strange noise. Most times, shortly after startup, and I think it has to be in gear, you can hear a servo noise or small electric motor noise that lasts about 2 seconds. I don't think it happens again until the next startup-----and it doesn't seem to happen every time---(I only have 200 miles so IDK), This seems to come either from the firewall or behind the glove box. Any ideas ??? Thanks in advance.

 

Part of the Emissions control includes a blower that pumps air into the exhaust to get the cat up and runing faster. It sounds like a little motor, and when it turns off you will hear a 'whoosh' sound if the radio/engine is quiet enough. This sound like it could be it?

 

could be----i've not heard the woosh but i'll check it out. This sounds like a little servo motor zzzzzz then its gone. It happens so fast it's hard to pin it down. But I'll listen a little more carefully today. THANK YOU

 

maybe the fuel pump.

 

More than likely what you are hearing is the ABS system going through a self check mode on start up and it is normal. The pump is mounted in the engine compartment near the firewall behind the glove box.

 

thanks guys., I found another link that pretty much describes my exact noise and confirms it the abs. thanks again