[Alekss]

I am trying to diagnose an annoying engine whine which increases with RPM so I am pretty sure it is something connected to the serpentine belt.
I have replaced the tensioner and idler pulleys. I also replaced the belt itself. I purchased a shorter belt (43.6") to bypass the A/C and noise is still there. I replaced the P.S. fluid and reservoir. The noise is still there. Next, I plan to look at the Power Steering pump itself. Which is why I am wondering if there is a shorter belt to put on temporarily to bypass the power steering pump? This will tell me whether it is the P.S. pump or the alternator. So If anyone has the belt size, please share.

btw. this is what the car sounds like:

https://youtu.be/A-KU4b-EySQ

[Serf27]

It’s hard to hear anything in the video, for me. A lot of static.

I’ve never heard alternator whine. I have heard alternator bearing rattle though, which sounds like a rattle/metal on metal and not a whine.

Does the whine get louder if you turn the wheel?
You can remove the belt and start the engine for a few seconds to see if the noise disappears.

[jadams161]

Have you run the car with the belt removed?? Thats where I would start.

[Suvorovo]

Haven't listened to the video.

Whine can be produced by a cheap oil filter if it's coming from that area. Can you double check that the filter element hasn't collapsed?

I agree with the above posters, alternator pulleys/powersteering pullies produce a rattle/metal on metal grinding noise. Power steering whine should change pitch when turning/holding in a lock position. I try to avoid locking my steering wheel since it puts the most pressure on the pump.

We're all running MANN filters. Or some other high quality brand that's not from autozone.

[Alekss]

Right, I removed the belt and the whine is gone. Also, I am using the MANN filter.
This is why I am left to believe it is either the P.S. pump or the alternator.

[Boston4]

Mechanic's stethoscope would help narrow it down - that'll allow you to listen to the alternator and PS pump in isolation.

The old trick is to use a long screwdriver and put your ear against the handle, and the tip against the pulley you're checking. Not sure if you'll have the room to do that in this case though.

[Suvorovo]

Originally Posted by Boston4

Mechanic's stethoscope would help narrow it down - that'll allow you to listen to the alternator and PS pump in isolation.

The old trick is to use a long screwdriver and put your ear against the handle, and the tip against the pulley you're checking. Not sure if you'll have the room to do that in this case though.

You can also cut a 2 liter bottle in half and insert the screw driver through it to amplify the noise without risking a pulley smacking the screw driver into your eye.

[jadams161]

PS pump. common issue

[Alekss]

I do have the Mechanic's stethoscope but I have no experience with knowing what the "healthy" P.S. pump sounds like vs one on its way out.

This is why, bypassing it with a shorter serpentine belt would be an easier method. So no length on this belt?

[e91Owner]

Originally Posted by Alekss

I do have the Mechanic's stethoscope but I have no experience with knowing what the "healthy" P.S. pump sounds like vs one on its way out.

This is why, bypassing it with a shorter serpentine belt would be an easier method. So no length on this belt?

I doubt anyone has done this. You can just measure it yourself though with a string and buy the appropriate belt.

[e90yyc]

How many kms on your car?

Does it change at all when you move the steering wheel—particularly when parked?

Here’s all the shit I’ve replaced:

• Power steering reservoir (OE)
• Power steering pump, twice (also OE, but thought perhaps the first one I got was bad)
• Steering rack (Genuine part, but used)
• Pulleys, belt (OE)
• Alternator (OE)

Despite all of that, I still have a whine. It’s probably way quieter than yours, but it’s there. When I bypass AC it’s still there, but when I remove the belt entirely it goes away.

I’ve given up on trying to solve it. Not saying you should—it’s probably the PS pump, especially if it’s original—but I’ve just accepted there’s a low-key whine that changes when I move the wheel.

[Serf27]

Never removed a PS pump and reinstalled.
How are the mounting points?

Is this a whine or a high pitch screech?

[whyzee125]

I don't know what a healthy pump sounds like with a mechanic's stethascope but I'd imagine you'd hear the same pitch/tone you're hearing through the device on the bad part. I'd imagine that listening with one of those tools to both, you'll know which it is.

I've not heard an alternator whine on an e90 but I've had it on a 4Runner before.

Does the noicse change at all by turning the steering wheel while stopped? I'd think if PS pump, you'd hear a bit of a change but that's not super scientific.

[Alekss]

Originally Posted by e90yyc

How many kms on your car?

Does it change at all when you move the steering wheel—particularly when parked?

Here’s all the shit I’ve replaced:

• Power steering reservoir (OE)
• Power steering pump, twice (also OE, but thought perhaps the first one I got was bad)
• Steering rack (Genuine part, but used)
• Pulleys, belt (OE)
• Alternator (OE)

Despite all of that, I still have a whine. It’s probably way quieter than yours, but it’s there. When I bypass AC it’s still there, but when I remove the belt entirely it goes away.

I’ve given up on trying to solve it. Not saying you should—it’s probably the PS pump, especially if it’s original—but I’ve just accepted there’s a low-key whine that changes when I move the wheel.

Replaced all those parts and still no change? I am surprised to say the least.
My 328 has 142k km. The car is in really good shape. I am a Honda guy but could not find me a TL-shawd in manual and I wanted an AWD manual car. SO the winning combination was a straight six cylinder awd vehicle with manual transmission. A lot of people say that these N52s are noisy and coming from a Honda this is a bit different for me

No change when I move the steering wheel..unless the RPM jumps a little then the whine increases with RPM.

[Alekss]

UPDATE on the issue, in case someone is experiencing the same in the future and is looking at this thread:

It was the P.S. pump. I purchased AAE 5799NH from Rock Auto and installed it myself.
The install was easy but take your time and don't rush. The hardest part was getting to the 22mm banjo bolt. I suggest removing the front splash shield and accessing the bolt from below. Also, removing the fan shroud helps free up space around the radiator and it only takes less than a minute to do. I had previously replaced my P.S. fluid and reservoir so no need to do anything there other than add a little bit of oil and burp the system.
I also obtained a new hose clamp 32416751127 and two banjo bolt gaskets 07119906463. I reused the original plastic pulley since it looked good with no cracks and was really easy to remove from the pump.