power steering pump whine
 

Let it get a little low, I think the rack is leaking. I can't remember if it was atf or generic power steering fluid and the noise went away but now the noise is back with a vengeance. Did i put an incompatible fluid in or did I get air in the system or did the pump bearing just kick the bucket?

First off, is the fluid top off? Most often you get that dreaded whine due to low fluid level.

yes fluid is topped off now :)

Is the whine still there?

yes

What fluid did you use?

i think it was 80% chance it was generic auto parts store power steering fluid. I may of just put atf in there since I typically will use that. It was a month ago that I added it. I have not been driving it much

My 06 CLS takes petrosin (I think I spelled that right) hydraulic fluid. CHF11. I would expect the E to be the same.

Same here. Use CHF11s on the E55. Autozone matched fcpeuro's price. AZ price was $10 more per can.

Picked up a 2L, one for the MB and one for the VW.

think its worth flushing it to try to get rid of the noise?

I have an 09 E63 and recently went rounds with my power steering. I used Febi-Bilstein Power Steering Fluid CHF 11S at $15 from Amazon. OEM and same manufacturer as the stuff above. I was told by multiple shops to switch our the reservoir first and see as the filter inside will clog and starve the pump; only way is to replace it. I picked up a new reservoir for $38 from mboem online parts or something like that. And it worked! quiet as can be.

regarding the pump, I was also told by multiple reputable shops, that it wont just be the pump pulley bearing that makes the noise, so you can rule that out. I did purchase a new pump from RockAuto as it was the cheapest over 6 or 7 our normal parts website at $240 or so (others wanted $400). Yes it's remanufactured but all them nowadays are and they don't make "new" ones anymore. Reman. is better than rebuilt (yes they are different I found out).

so do the reservoir first....took me like 30 mins to replace, then bleed the air out carefully; instructions are in another thread. results will be noticed fairly immediately if its the filter in the res.

So did you inspect the pump you received from Rock? Compare it to stock?

I ordered a reservoir and will flush. It would make sense that its starving for oil since it sounds like its low but its full