Hi guys, I've recently developed a whining noise that starts at around 2000rpm and goes away when I take my foot off the gas. Comes back again when I reach 2000rpm and so on. Only just started a few days ago. Stays the same pitch throughout, not sure how far into the rpm range it stays for.
Any ideas what it could be ? Cant really pinpoint where it's coming from but isn't speaker feedback.
Car is a stock auto 305tpi with 62100miles.
Cheers.

 

Whine? Is it possibly a whistling noise due to vacuum leak?

 

definitely more of a whine than a whistle.. Can't rule out a vac leak though I guess. Had been meaning to get a smoke machine to test for one to rule it out of my small misfire, which I now think is related to my excess fuel use.
Old cars never give you a moments peace lol.

 

Hi KR81, it's more like; "ALL cars never give you a moment's peace" .

A zillion years ago when I was a young mechanic, my favorite old guy mechanic mentor used to say to me in his gravely voice; "Kid, , , never forget, if it's got **** or wheels, it's trouble!"

Man oh man was he ever right !!!!!

 

Ain't that the truth

 

Does the whine change pitch with engine RPM? Does it increase in volume with load?

 

Alternator whine?

 

Stays the same.

I thought that, is that an indication it dying ? I did recently add a 2 channel amp for my front speakers, in addition to a small monoblock for my sub I've had for years but the noise started well after the install..

Also the Alternator was new in mid 2015 and probably has less than 5000miles on it. Battery is quite old though, maybe 6/7 years, don't know if that's relevant though.

 

You said its not speaker feedback, so is it underhood noise? Maybe the bearing on the alternator or even a idler pulley/bearing. If so, id spray a little lube on those areas to start. 2k rpm is about where the alt kicks into high gear i believe.

 

Hi guys, I've recently gone back to determine what this sound is and it is 100% coming from the alternator once it hits 2k rpm and will stay if above that rpm and go away when it drops back under 2k and continues this cycle. It's never done it until around the original date of this thread and I've since put in a new alternator and it does it with the new one too.
I've since disconnected 1 of the 2 amps so I'm back to only having 1 amp power a sub which is what it's had since I bought it but still it persists.
Any ideas why the alternator/s have started making this whine noise ?

 

If you've replaced the Alternator, I can't see two alt's doing the exact same thing the same way.

Could it be the power steering pump?

 

Unfortunately not, I stood right in front and took it past 2k rpm by opening at the throttle body and imo is definitely coming from the alternator.

Here's a video:
WARNING LOUD!!

 

Okay, that's not a whining noise in the bearings, that sounds a lot like an electrical noise. You need to start checking the charging system out.

 

Thirdgen89GTA has a good point. I have heard the power steering pump do this before. Turned out, when the PS fluid was checked, it actually was low. Topped off, and sound went away. I would still check the pump for shitz n giggles...it's free to do.

 

Cheers guys i will check it. Had it rebuilt recently but I haven't noticed any fluid leak.

 

Hi KR81, Tell me, have you tried the trick where you take a 3 foot piece of a wooden broomstick held to your ear and touch the alternator, power steering pump, and everything else that spins on the front of the engine to nail down where the sound is coming from? I know this method is "old school" but when you develop a feel for it you'd be amazed at how easy it is to pinpoint a noisy component

 

OrangeBird I'll try that.

 

Wow...I didn't hear it from the engine compartment, but when you moved around to the passengers side door, it's quite noticeable.

 

Hi guys. I've brought up this problem before and haven't been able to solve it and now I'm back to trying to solve it 😆 I'll link the other post I made earlier this year for anyone who wants to look but I'll outline the issue again here.
This noise randomly started one day, hadn't done any recent work or maintenance, literally just came into my life lol. It used to start at 2k rpm and go away after a few seconds or if I eased off the throttle. Now it's starting at 1500 rpm. Comes back and goes every time I hit 1500 and goes away as outlined above. Seems to be coming from the area shown in the video. No where near the alternator as I previously thought or pulleys or power steering pump as others suggested to check. Really annoying and I feel like it's building slowly to something bad.
Any advice much appreciated.

Warning! Video is loud!!

https://youtu.be/JI-Y-iko-2A

Old thread: https://www.thirdgen.org/forums/tech-general-engine/779151-whining-noise-2k-rpm.html ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

 

It would be helpful to remove the accessory drive belt and briefly run it again while the engine is still warm. That will isolate a lot of potential items.

 

I don't think I ever saw the vid (link not working), but any chance it could be the blower fan. Someone mentioned it got louder on the passenger side. Not the first time that sucker of fooled me.

 

841LE No, it seems to be coming from the passenger side but like halfway up the engine bay, pretty much exactly around the view in the video in my previous comment.

 

How long can I run it without the belt on before it'll over heat etc.. ?

 

Without putting it under load (in gear, driving) it should be able to run 3-4 minutes before the coolant really starts to get hot.

It may interest you to know that a lot of engines in autos, trucks, and implements used convection cooling (called thermo-siphoning) for many years before someone thought that a water pump was a good idea.

 

Hi guys, just resurrecting this to post a conclusion.
The noise was coming from the smog pump. Removed it and ran a 6PK2460 serpentine belt then test drove it and no noise anymore!
Thanks for everyones advice!