High-pitched whine on acceleration? (No s/c)

[Hujan]

Last Tuesday I started noticing a really high-pitched whine when I accelerate. It comes on above 3k RPM and stays until I go back down in the rev range. The harder I accelerate, the louder it is. It honest to God sounds like I have a supercharger installed. It sounds a lot like the video clips I've heard of the Harrop kit or the people with solid/delrin differential bushings.

Dealership said they don't know what it is. Anyone have any idea?

[Ezio]

a lot of the times whining sound comes from the transmission

[C-M2]

Does it sound like it's coming from infront of you? Or next/behind you? If it's from the front I would check the air box to make sure it has a tight seal.

[sylonien]

Does it sound anything like this?

[s14_kev]

It could be low power steering fluid level. I'd try topping it off and see if that helps (you can pick up the Pentosin fluid at Oreilly, AutoZone, etc.).

I had the same sort of noise and that's what it ended up being, unfortunately I don't have a video of the sound. Good luck!

[Sered]

Mine ended up being my tensioner pulley, it was a little loose. I didn't discover this until I put my blower on, so there's a different kind of whine now haha

[C|3R1C]

Originally Posted by kevin///mlee

It could be low power steering fluid level. I'd try topping it off and see if that helps (you can pick up the Pentosin fluid at Oreilly, AutoZone, etc.).

I had the same sort of noise and that's what it ended up being, unfortunately I don't have a video of the sound. Good luck!

+1 on this. Pop the cap open when it cold and check the level.

[Hujan]

Thanks for the replies, guys. Much appreciated.

Originally Posted by C-M2

Does it sound like it's coming from infront of you? Or next/behind you? If it's from the front I would check the air box to make sure it has a tight seal.

Hard to tell, but I believe coming from in front. I will check the airbox to make sure it's tight.

Originally Posted by sylonien

Does it sound anything like this?

Nope. Nothing like that. I sounds a lot like the sound in this video at 0:19:

Originally Posted by Sered

Mine ended up being my tensioner pulley, it was a little loose. I didn't discover this until I put my blower on, so there's a different kind of whine now haha

Thanks for this. How did you tighten it?

Originally Posted by kevin///mlee

It could be low power steering fluid level. I'd try topping it off and see if that helps (you can pick up the Pentosin fluid at Oreilly, AutoZone, etc.).

I had the same sort of noise and that's what it ended up being, unfortunately I don't have a video of the sound. Good luck!

Originally Posted by C|3R1C

+1 on this. Pop the cap open when it cold and check the level.

Thanks for commenting guys. Man, I would love for it to be something as simple as that. I don't see anything that appears to be a dipstick for the power steering fluid. How can you tell if it is low? How much is supposed to be in there? Also, do you have a link to the exact fluid I need? Thanks!

[s14_kev]

Originally Posted by Hujan

Thanks for the replies, guys. Much appreciated.

Hard to tell, but I believe coming from in front. I will check the airbox to make sure it's tight.

Nope. Nothing like that. I sounds a lot like the sound in this video at 0:19:

Thanks for this. How did you tighten it?

Thanks for commenting guys. Man, I would love for it to be something as simple as that. I don't see anything that appears to be a dipstick for the power steering fluid. How can you tell if it is low? How much is supposed to be in there? Also, do you have a link to the exact fluid I need? Thanks!

http://www.turnermotorsport.com/p-56...FQGtaQodSFAAjA

I honestly just eyeballed it. Not sure of the exact amount but it's cheap enough that you could just pick up a bottle and add a little at a time so you don't over fill it. I believe if you over fill it, it will just leak out of the reservoir a little bit. This happens at the track too when the fluid heats up and it is meant to "vent" out this way. I have a microfiber towel ziptied around the cap for this reason. Let us know how it goes!

[C|3R1C]

On the power steering fluid cap look on the thing sticking down. there are two notchs/levels. the top notch is the full and the lower notch is the minimum. just take off the cap, wipe off the stick, gently screw it back on a remove and see where the wet line is.

[Hujan]

Originally Posted by kevin///mlee

http://www.turnermotorsport.com/p-56...FQGtaQodSFAAjA

I honestly just eyeballed it. Not sure of the exact amount but it's cheap enough that you could just pick up a bottle and add a little at a time so you don't over fill it. I believe if you over fill it, it will just leak out of the reservoir a little bit. This happens at the track too when the fluid heats up and it is meant to "vent" out this way. I have a microfiber towel ziptied around the cap for this reason. Let us know how it goes!

Originally Posted by C|3R1C

On the power steering fluid cap look on the thing sticking down. there are two notchs/levels. the top notch is the full and the lower notch is the minimum. just take off the cap, wipe off the stick, gently screw it back on a remove and see where the wet line is.

Thanks guys. I really think this be the issue. I'll tackle this today and follow up.
Oddly, Turner reports that the Pentosin CHF11S does work for the E92 M3. Seems to be the right fluid, though, no?

[s14_kev]

Turners website is wrong, sorry for the bad link. The reservoir cap should have a green label that says CHF 11S only and Pentosin is the OEM brand

See part #1 here:
http://www.realoem.com/bmw/showparts...36&hg=32&fg=20

[Hujan]

Originally Posted by kevin///mlee

Turners website is wrong, sorry for the bad link. The reservoir cap should have a green label that says CHF 11S only and Pentosin is the OEM brand

See part #1 here:
http://www.realoem.com/bmw/showparts...36&hg=32&fg=20

No green label on mine. It must have fallen off?

Anyway, I checked the level this morning and it was below the "dipstick" on the cap. In other words, the protrusion on the cap was bone dry when I pulled it out of the reservoir. Not good, Mav.

I stopped at O'Reilly's a couple miles from my house on my way to work and bought a can of Pentosin CHF 11S. I had to put quite a bit in there to get it up to the upper most of the two level indicators. The sound did not immediately disappear, but seemed to lessen over the course of my drive. I tried to turn the wheel back and forth at stop lights to flush some fluid through the system. Hopefully the noise is all gone on my drive home today.

One other thing: The fluid in the reservoir looked like yellowish brown and was faintly foamy/frothy. The new stuff was a light, clear green. I'm wondering if it would be a good idea to do a complete flush? If so, any DIYs on that? I am going to change the engine oil this weekend anyway.

[Beemdog]

Normally as the Pentosin 11S ages it darkens and picks up some black contaminants. Yellowish-brown color would seem to indicate a non-Pentosin fluid used. I would flush it.

Although on most other cars the P/S flush is usually accomplished by disconnecting a fluid return line and running the car for ~8-10 seconds, all the DIY articles I read on the M3 seem to advocate simply draining the reservoir multiple times as completely as possible (I used a Mity-Vac hand pump) and running it a couple minutes while turning the steering wheel lock-to-lock after each re-fill. It takes about two cans of Pentosin to flush it this way (about 6 drain and fills). I got sick of doing this after 4 re-fills and did two more drain and fills on subsequent weekends after driving the car around for a week.

[C|3R1C]

I would check your manual for the right fluid. I think bmw made a change from the first year or so. There's a DIY to fully drain the system at the steering rack. It's cake. Just pull out two bolts, let the fluid drain, turn your steering a couple times to make sure it's out, then put back the bolts and fill. The whole ps system is self bleeding so when you fill it with the car on it was suck in the new fluid and discharge the air so just keep adding until you hit the marks.

[Hujan]

Originally Posted by C|3R1C

I would check your manual for the right fluid. I think bmw made a change from the first year or so. There's a DIY to fully drain the system at the steering rack. It's cake. Just pull out two bolts, let the fluid drain, turn your steering a couple times to make sure it's out, then put back the bolts and fill. The whole ps system is self bleeding so when you fill it with the car on it was suck in the new fluid and discharge the air so just keep adding until you hit the marks.

Good idea on the manual.

Is this the DIY you had in mind?

http://www.m3post.com/forums/showthr...ighlight=power

It sounds a bit complicated.

[askjeeves]

I had a whining from the front that changed as rpms fluctuated. Turned out to be a pulley. Not sure if the dealership just tightened one up it replaced it.

[C|3R1C]

Yea that's the DIY. It's actually really easy. There's another on a 328/335 that's the same too. Google the torque specs for the bolts. It's the same as non m cars. I don't remember off the top of my head. It's as simple as take out the bolts, let's drain to empty, put back bolts, fill reservoir, turn on car, let it suck in fluid, put more until full. Done. It's really easy.

[M_Time]

I had that same issue a few years ago, I noticed it was getting louder. I Took it to the dealer, and it turned out to be a faulty oil pump. When it goes bad it sounds like a SC.

[Hujan]

The sound didn't really get better when I added the PS fluid. I'm going to attack the pulleys next. If it doesn't get better, I'm going (back) to the dealer to get it sorted out.

Originally Posted by M_Time

I had that same issue a few years ago, I noticed it was getting louder. I Took it to the dealer, and it turned out to be a faulty oil pump. When it goes bad it sounds like a SC.

That doesn't sound good at all. Did the pitch/volume rise with increased RPMs?
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[Sered]

To get to my tensioner, I had removed the intake scoop-thing off the top of the fan, then had removed the fan. I removed the fan because I was installing my blower at the time. You can probably get to the tensioner bolt without needing to remove the fan, it'll just be a bit cramped. If you look at the tensioner pulley, the bolt is to the upper left of it. Mine was loose causing it to wobble. The tensioner I am referring to is the tensioner for the water pump and alternator belt.

I had previously checked my PS pump and fluid and my idler pulley for the A/C and PS belt.