I've occasionally noticed that on a cold start the power steering pump will be a bit noisy. I've only noticed it a few times over the past few years, but yesterday I was under the hood right after starting the engine after it had sat a few days, and I recorded this horrible noise it was making.

The noise went away after the engine warmed up. This is on my 98 Mazda 626, and I'm wondering if maybe this indicates a problem with the PS pump that could be putting mechanical drag on the engine and causing it's low, rough idle under load.

EDIT Jan. 24th, 2018

I checked this morning, the PS was 12*C/53*F and made no noise on start up. I noticed a few small bubbles right at start up, but that was it.

  • 1
    I'll go out on a limb and ask you if you've checked the fluid level for the ps pump? Jan 23, 2018 at 13:29
  • @Pᴀᴜʟsᴛᴇʀ2 Fluid level is completely normal. Like I said, I've noticed this a few times over the past few years, but it's never sounded this bad before, and it always goes away after running a few minutes. Jan 23, 2018 at 14:18
  • Has the power steering fluid ever been changed? Does this only happen when the outside temps are very low?
    – CharlieRB
    Jan 23, 2018 at 15:29
  • 1
    I'd suggest flushing the system. If that doesn't help, you probably are looking at a new pump. The pump on my Silverado has been noisy since I bought the truck (used) about eight years ago. I've not had any problems with turning the wheels so I haven't worried about it too much. It has gotten a little noisier over time, but it still works. If it's something you can live with, you might just let it ride. Jan 23, 2018 at 17:15
  • 1
    Are there any bubbles or foam in the fluid when it is noisy? Jan 23, 2018 at 18:41

2 Answers 2


Since a lot of other sources speak about an alternator squealing, I'd like you to test something to confirm the source. Initiate a "squeal event" in the driver seat and do one of 2 things while its making the noise.

1.) hit the rear defrost, if it gets louder its alternator related.

2.) turn the wheel, if it gets louder or changes its the PS pump.

The slower way to do this is to get a friend to start the car in a way that produces the noise after removing the belts, one at a time. That would also let you know which belt system is connected to the culprit. The only other thing that that isn't PS fluid level that could affect or make that noise (that I can think of) is trans fluid level.

Belt tension is the most likely cause in either system. next order of likeliness is a bearing. If nothing changes the sound (or you can't reproduce the noise consistently enough to test) you will have to wait until spring and ask again if it ever makes the same noise in warmer weather.


IMO, I believe this is related to old fluid in the system. Like other oils, power steering fluid becomes contaminated with age. The sludge, grit, moisture, and other contaminants that build up over time will cause flow or pressure issues.

Since it is much less expensive, I would suggest changing the fluid before changing the pump. There are a number of Internet sources showing how to change the fluid, so pick what works best for you.

Sources -
Do I Really Need to Flush My Car’s Power Steering Fluid?
Do You Need To Change Your Car's Power-Steering Fluid?

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