99 Explorer start-up noise

[akcrxnj]

Truck is making a weird noise during cold start-ups. The noise is audible when the temperatures get below 32F or so. The colder the temperature the longer the noise lasts. I have uploaded a video which I took this morning. The temperature outside when video was shot was 10F.

 

[akcrxnj]

Can this be the power steering pump. The last thing I did was change out the fluid in the power steering pump. I added some of the Lucas Power steering fluid in as a proactive approach. I changed out the fluid last night and replaced with Synthetic ATF. I haven't heard the noise since (3 starts). Could this have been the problem? Does the power steering pump run at start-up? If the noise does not return I am planning on removing the fluid again one more time just to make sure I get as much of that old stuff out of there.

Lucas Power Steering Addative.
http://www.lucasoil.com/products/di...w&headTitle= - Lucas Power Steering Stop Leak

 

[n2epv]

I would guess that it's the power steering pump! If the old PS fluid was dark and cloudy, then it needed changing anyway - flush it again if it isn't completely clear now. The suspended dirt particles in the old fluid will wear the pump (cheap and easy to change out) and the steering rack as well (which isn't so cheap or easy to replace). Looks like the noise got your dog's attention, too!

If it growls again on a cold morning, move the steering wheel back and forth - if moving the wheel changes the sound, then it's definitely the pump.