Cold PS Noise

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Sep 14, 2015
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885
Location
NE Ohio
Hi all,

The power steering on the expedition is making noise when cold. It subsides some once it's warm but you can still hear it.

Does a fluid change usually resolve this? I've read where people have changed to a different fluid, currently it's got what I'm assuming is factory fill of Mercon LV, I have topped off. No steering difficulties have been encountered.

My first thought is that the pump is bad but want to eliminate simple solutions first.
 
Hi all,

The power steering on the expedition is making noise when cold. It subsides some once it's warm but you can still hear it.

Does a fluid change usually resolve this? I've read where people have changed to a different fluid, currently it's got what I'm assuming is factory fill of Mercon LV, I have topped off. No steering difficulties have been encountered.

My first thought is that the pump is bad but want to eliminate simple solutions first.
Worked for me.
 
Thanks for the replies so far. Those of you who have changed PS fluid for this reason, did you use OE spec fluid or something else?
 
I'm not advocating for it without research, but I'd swear I've heard of people using 'Honda Spec' PS Fluid in other pumps and it worked well for older things. The Honda fluid is slightly thicker and has a few more additives in it or something along those lines. I'll have to see if I can dig up the posts. Maybe @MolaKule remembers that.

--Edit--

Found the discussion of what's in it:


--Edit Edit--

Might have been this one:

 
Last edited:
Hi all,

The power steering on the expedition is making noise when cold. It subsides some once it's warm but you can still hear it.

Does a fluid change usually resolve this? I've read where people have changed to a different fluid, currently it's got what I'm assuming is factory fill of Mercon LV, I have topped off. No steering difficulties have been encountered.

My first thought is that the pump is bad but want to eliminate simple solutions first.
I used M1 ATF in my 04 Expedition and it was quiet after changing, just a slight noise before when cold as well. My 94 F350 was changed to Lubegard PS fluid as it had typical Ford whine when I got it this year on unknown ps fluid, clear. Lubegard ps has made it a lot quieter but still has an acceptable whine when cold. Not sure what year Expedition you have but fluids can help.
 
I used M1 ATF in my 04 Expedition and it was quiet after changing, just a slight noise before when cold as well. My 94 F350 was changed to Lubegard PS fluid as it had typical Ford whine when I got it this year on unknown ps fluid, clear. Lubegard ps has made it a lot quieter but still has an acceptable whine when cold. Not sure what year Expedition you have but fluids can help.
The OBS C2 pumps were horrendous. A Sag swap is the only sure way to gain quiet, and you'll be pleasantly surprised at the additional assist. Ford never used the C2 in the vans, and that's telling.

For the OP, I'd at least suck out the fluid and try fresh. I doubt it'll make a difference but will cost, what, under 2 qts? I'd probably just use VML 'cause it's readily available but maybe there's a better option.
 
I've used John Deere Hygard LV (J20D) in power steering and hydraulics with good results. For some people its easy to find and the price is usually not bad. A THF that meets J20D would be similar but you don't need the friction additives in steering /hydraulics applications. Don't think it causes any harm though.

The noise you are hearing is likely cavitation and definitely a sign of trouble. A higher quality, fresh fluid should help. Add some magnets to the reservoir if you can.
 
I suggest finding an appropriate low viscosity or synthetic fluid.

My Trailblazer was horrendous during cold starts. Usually past that -15/20c mark it would honky and whine. I lived with it for about 6 years. Finally replaced it with some Amsoil synthetic ATF I had, which was eventually replaced over the years with a group 4 based ATF. All but cured the noises. Around that -35/40c mark she will make some milder noises.
 
Hi all. Thanks again for the replies. I opted for Lubegard Synthetic fluid. It is specced to replace the prescribed Mercon LV (and a ton of other fluids). So far I've exchanged 2x reservoirs worth and the noise isn't gone yet. You can barely hear it at idle but it whines audibly from inside the cabin on acceleration.

No leaking noted via fluid level retention and no loss of power assist.

Old fluid is very dark and smells like every other power steering fluid I've smelled.
 
Finally figured this one out. It was the stupid tensioner idler pulley. When none of the other PS symptoms showed up I used a long breaker bar followed by an actual stethoscope and confirmed it was the tensioner idler.

Oddly, the one that came off looked like OEM Ford but had a "CHINA" bearing on the pulley.
 
Finally figured this one out. It was the stupid tensioner idler pulley. When none of the other PS symptoms showed up I used a long breaker bar followed by an actual stethoscope and confirmed it was the tensioner idler.

Oddly, the one that came off looked like OEM Ford but had a "CHINA" bearing on the pulley.
Thanks for the update! Post a pic of the squeaker?
 
Thanks for the update! Post a pic of the squeaker?

IMG_20250325_150802855_HDR_AE.webp
 
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