paroxysym

injectors/fuel pump... or i think when i had a prob with my smarty/FASS bob wagner told me its the truck cycling through the fuses.

Spooler

It's the vaccum pump running. 03-04.5 trucks still have them. They went away after drive by wire that came out in 05'.

worldindustries

I have had it since day one, pretty sure its the injectors doing a test or purging air, normal

sallyman1

vacuum pump for what? for the brake booster? where is it located?

RonP

The vacuum pump does make noise ocassionaly, but I am sure you are hearing the injectors cycle lieka few folks have mentioned. Mine will do it everytime I turn my key to the on position and has for the last 108,000 miles.

AH64ID

The tick he is referring to is most likely the injectors as other have mentioned.. My 05 and my dads 06 do it also.

I didn't think any 3rd gen had one? Or are you referring to an elec one?

SuperGewl

Is the noise on the passenger side near the firewall?????
Does your cruise control work properly?
It may be your vacuume pump running, may was makeing all sorts of noise due to the line being split and the pump was not mounted properly due to the install of the exhaust brake.

Spooler

On the passenger side behind the battery from what I remember. It is used for the cruise control only to actuate the dashpot for 03' to 04.5' trucks.


You can get a clicking sound when you first fire a truck up and yes it is due to air purging out of the system unless you have an Airdog like I do and you don't get that noise anymore

xtoyz17

I get a noise from the passenger side firewall near the glovebox anytime I unlock my doors it seems like. First thing in the morning when I unlock and open truck I can hear something near the glovebox, and it will do it if I lock and unlock the doors again? I'm an 06, so no vacuum pump. Anyone have any ideas? This morning I actually heard it more towards my radio, it almost seems like it's the HVAC actuators moving?