Noisy Power Steering Pump

2001 dodge caravan. After sitting in cold weather (say 40 degrees and below) overnight, the power steering pump makes a loud whining noise when car is started. It goes away after a minute or more (depending how cold it was overnight, colder = longer).

I changed the power steering pump and belt with slight changes in sound but the problem still exists…

Thoughts?

I suspect there is a remote fluid reservoir that feeds the pump. There will be a fine filter screen inside the reservoir through which the fluid must pass…If it’s plugged up, the pump will starve and make a lot of noise. Remove the reservoir and clean the screen…Use a turkey baster to suck out the fluid first…

My 2006 does the same thing…thanks. I’ll check the filter. Also, it will make the same sound when you back up if the fluid gets low. My dealer said I had a minor leak, but so far after two months the fluid level is steady and no sound backing up.

I realise you are not operating as a professional mechanic but the first step a pro whould take is to check for bulletins (from Dodge) perhaps the problem and fix has already been worked out.

One of the first steps in auto repair (after verifying the problem) is to check for bulletins.

Good Call. I actually detached the return line placed it in a plastic bottle and started car for a few seconds to flush out most of system fluid, this drained the resevoir which exposed a filter that can be seen only thru the fill cap. I could not access filter to remove, so to test your theory I poked holes in filter, refilled system w new ATF+4 and sound is gone. Definately a restricted flow issue. I will order a new resevoir and replace.
Thanks for the help.

It is kind of weird that in warm conditions enough could get by filter to not cavitate pump, but during cold nights 20f and below the viscosity of ATF changed enough to cause noise.
Now how to fix those sticky shock strut pivots ???..

This is almost a universal problem…As cars age, particles or rubber flake off the power steering hoses and slowly plug up the reservoir intake filter. Few people, including professional mechanics, even realize it is there…