My e46 M3 is making the tell-tale whining and groaning of a power steering pump that is either out of PS oil, or gasping it's last breath. The oil level is fine, so I immediately jumped to the conclusion that the pump is bad. The thing that gives me pause is that the noise goes away after a few minutes, which seems odd. Do PS noises like this normally go away? The steering feels totally normal, still.

Also, I have read that a collapsed return line (to the pump) from PS rack could cause the same symptoms. Will a collapsed hose be obvious from a visual inspection? How do I differentiate between a collapsed hose and a bad pump?

Thanks, Jeremy

  • Odd, my E60 M5 does the same thing. I would check the return line for any kinks. Are you leaking any fluid? Have you tried bleeding the ps system to see if there is any air in the system?
    – NoCarrier
    Commented Mar 15, 2011 at 22:40
  • PS pumps are self-bleeding, so I can't imagine the issue is being caused by air in the lines. Also, I don't see any leaks on the garage floor, so that doesn't seem like it would be the cause.
    – JeremyP
    Commented Mar 15, 2011 at 22:51
  • Do you have a combo/serpentine belt, or a dedicated PS belt, and if a dedicated one, are you positive it's not belt slippage? Hmm, okay, just realized it's a BMW, going to guess serpentine and that the belt probably isn't the problem...
    – NSGod
    Commented Mar 22, 2011 at 8:50
  • Now, in 2017, the noise is the same and the power steering system still works fine. I guess it's normal.
    – JeremyP
    Commented Feb 26, 2017 at 11:27

2 Answers 2


My power-steering pump failed about 2 months after the noise you described. I'm in an E46 3 Series. The noise would be louder when turning at a slower speed than it would at a higher speed. Dealer labour and part came to $1600 CAD, warranty saved me there.


A lot of BMWs have a noise, but it might be a pump going bad. If I remember right, the lines are right under the reservoir. Check them for softness, and if they are soft/chewy I guess you can replace them. If it's a pump, run until it pops, as they are like $400. As far as the lines from the rack, those are hard lines, and unless clearly pinched not sure if you can see anything.

  • 1
    chewy is a gross image for a power steering line yet also absolutely perfect. Well done! ;-)
    – Bob Cross
    Commented Jun 5, 2011 at 19:30
  • @Bob Thanks. I do try to give the best description for the condition =-) Commented Jun 11, 2011 at 19:29
  • Chewy hoses? ;)
    – jp2code
    Commented Jun 14, 2011 at 17:41

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