Troublesome Whining From Engine

[Ron17]

Starting about two weeks ago, I began to notice a medium-pitched whining coming from my engine. I can make it out very easily within my car when I turn the radio down. As the RPMs go higher, the whining gets higher pitched. As the RPMs come down, it gets lower pitched.

Along with this, I can actually FEEL the vibration in my steering wheel. It's slight, but perceptible. I was originally thinking that my power steering fluid might be low, but I notice this when the wheel is completely straight -- not just when the wheel is cut one way or another.

The more I try to locate this, the more I am beginning to feel like it is my alternator or something. I lifted the hood yesterday and revved the engine some, listening for the sound and trying to pinpoint it. I almost convinced myself that it was coming from the alternator, but I'm not sure if it is or not.

If anyone could shed some light on this, or how to track down just what it is, please let me know, as it seems to be getting worse as the days pass.

[mtrsprt3/ny]

It's your alternater. Mine had the same symptons until I swapped it out.It's starting to go bad.

[mrkurz]

I agree on the alternator...but it could actually just be a bad belt or pully too.

[Ron17]

Thanks -- that's what I was afraid of. About how long do you estimate I've got until it leaves me stranded? If I can, I'd like to make it to the Christmas Break, when I'm going to be doing TONS of work on my car, so I can do the install myself.

Also, how can I differentiate between belt/pully and actual alternator failure?

[Ron17]

Also, how easy is an alternator replacement to do as a self-install job??

[Ron17]

I just spoke with the $tealership about pricing for a new alternator and some other possibilities arose during my discussions with them...

I have heard about people having the bearings in their tensioner pulley go bad, which would cause problems. Could these symptoms be associated with that problem? I'd MUCH rather replace a pulley than I would an alternator.

Or, it could be another pulley aside from the tensioner.

So, how would I diagnose pulley/tensioner failure versus alternator failure. Well, not COMPLETE failure, but prelude to a failure. Diagnosis tips?

[Jim O.]

Use a mechanic's stethoscope to track down the source of the noise. If you don't have one, you can use a long screwdriver - press the handle against the bone near your ear, and touch the tip near the places where you think the noise is coming from. DON'T TOUCH IT TO MOVING PARTS, unless you want to hurt yourself...

You can also carefully shoot some spray lube into the bearing on the tensioner pulley, and see if the sound changes or goes away. If it does, then the pulley is bad.

Jim

[svb]

I have this exact engine whine come up recently. Ron 17 what did your problem end up being? Was it the alternator or pulley?

[BCM M3]

Maybe somebody secretly installed a supercharger while you weren't looking....


that'd be sweet.

[TedStriker]

I had the same problem as well. I first thought it was the idler pulley, so I ordered one. I should have loosened the belt first to turn the components to narrow it down. It was the alternator. The bearings were making a whining noise and were going bad. It's not hard at all to replace. Pop the cap off of your idler pulley, and use a hex key to turn the pulley "clockwise" as if to tighten it. This will cause it to move down and the belt will slide off. Then you will be able to turn the pulleys and alternator to pinpoint the problem.

The stealer wanted around 380$ for an alternator, and Napa wanted like 400$. I bought one at Pep Boys for 225$ and a LIFETIME warranty and replaced it in 30 minutes. Hope this helps.

[Ron17]

Originally posted by svb
I have this exact engine whine come up recently. Ron 17 what did your problem end up being? Was it the alternator or pulley?

As it turns out, it was the power steering pump. I had a slow leak in one of the hoses or maybe a bad clamp. I topped off the power steering fluid reservoir and the sound/vibration magically went away. It would come back a while later, though, and I had to top it off again.

I totalled the car before I could fix it (this was on my old Cosmos one). Never to fear, though... I have another M3 now.

[XOC]

Reading this, I was thinking that an easy way to isolate engine sounds would be to get a cardboard tube, like the kind christmas paper is wrapped around, and hold one end up to your ear and use the other end to scan around the engine, close to the parts in question.

[svb]

Thanks for your reply Ron 17...I topped off my ps fluid reservoir and guess what...the sound went away. I must have a slow leak somewhere in the power steering system too...no surprise there with these cars.

[mck325is]

Originally posted by XOC
Reading this, I was thinking that an easy way to isolate engine sounds would be to get a cardboard tube, like the kind christmas paper is wrapped around, and hold one end up to your ear and use the other end to scan around the engine, close to the parts in question.

You can pick up a mechanic's stethoscope at auto parts store for the same purpose, you can really hone in on faint noises. Great for isolating engine noises or possible wheel bearing failures etc etc etc.

[djm1k0]

I had the same problem as well. I first thought it was the idler pulley, so I ordered one. I should have loosened the belt first to turn the components to narrow it down. It was the alternator. The bearings were making a whining noise and were going bad. It's not hard at all to replace. Pop the cap off of your idler pulley, and use a hex key to turn the pulley "clockwise" as if to tighten it. This will cause it to move down and the belt will slide off. Then you will be able to turn the pulleys and alternator to pinpoint the problem.

The stealer wanted around 380$ for an alternator, and Napa wanted like 400$. I bought one at Pep Boys for 225$ and a LIFETIME warranty and replaced it in 30 minutes. Hope this helps.

how exactly did you replace the alt. i would like to do it myself but i'm not too sure of exactly what to do can you shed any light on the install what's entailed ?

thanks.

[fgraziano]

take off the belt, undo the 2 bolts, undo the wires, pull alternator out, use a gun to take the pulley off, put the pulley on the new alternator ( if it didn't come with one of course) put the bolts back in, reconnect the wiring, put the belt back on, i timed myself, did this in 6 minutes the other day. haha

[djm1k0]

ok i think this is one of those things that's easier said than done, how do i get to the belts for starters then how do i get them off ? i think changing out the actual alt will be the easy part.