What’s this whining/whistle noise? Alternator bearings?

[Toyolo_Camper]

I have a manual 2C engine and just notice a whining/whistling directly linked to engine revs, it almost sounds like I have a turbo when shifting from 1st-4th and when I engage the clutch the sound is temporarly gone. I’m guessing this is probably a faulty bearing within the alternator assembly?? Any other thoughts to other components that can cause this sound? I read somewhere that the vacuum pump could also be suspect...

If it is the alternator, how difficult is it to access and remove it?

[JDM VANMAN]

Just out of curiosity, is your stereo playing while driving, shifting, acceleration? The reason why I ask is cause the sound goes away when you press the clutch and the RPM’s reduces, could be a bad ground in your stereo or amp and your getting some (turbo spooling sound) feedback thru the speakers upon acceleration?

Maybe I’m totally off topic but it’s something that could be eliminated if it’s not the case.

JDM

[Burntboot]

JDM has a valid point, especially if the van is new to you.

However, I would tend to think that if pushing on the clutch pedal makes the noise go away then the noise is likely within the clutch/trans assembly.
Think throw-out bearing, maybe?

Generally speaking, alternator noises do not change with clutch engagement.

[Toyolo_Camper]

I’ve owned the van for some time now, it’s got about 116k miles on the clock. About the radio, that’s an interesting thought, didn’t realize this could also create a phantom sound, but I had the radio off during the test drive. The other day I had the engine cover off and was pulling on the throttle and couldn’t really hear it the noise well, however I can kinda hear it when I drive and more so when I slow down right before downshifting, so I guess a bearing in the clutch assembly would make more sense. I also have a cigarette adapter that reads the tire pressure and alternator current. Last weekend I completed a 3 hour after discovering the whine, and the voltage meter stayed between the usual 13.3-14.4v. Also it appears the noise was louder at first, and now after driving 170ish miles, it’s more subtle. Could extra dirt cause the clutch to temporarily make noise? I was driving on muddy surfaces, prior to camping, and then the next morning it appeared and slowly has improved, but still slightly audible.

if I don’t have access to a lift, would repairing the clutch assembly require this? Any thoughts on how th proceed next?

[Burntboot]

Sadly there are no short cuts when it comes to diagnosing problems.
Weird problems only require more diagnosis.
Diagnosis, at least in the moment, always seems like the biggest waste of time, that is until you find the smoking gun, but even sometimes then it can still seem wasteful.

Dirt can indeed cause problems, but shouldn't be getting inside the clutch/transmission.
Usually a good cleaning is enough to dislodge anything the is at issue.

If your problem is in the trans/clutch you will have to pull the transmission out.
Totally doable in the driveway but by no way a fun job and not something you want to dig into unless its necessary.
And if you're going to drop the trans to investigate you will probably want to action things while there, just because you are in that deep, think new clutch assembly, release and pilot bearings, if the input bearing needs attention now is also the time cause your right there.

A lift isn't absolutely required for jobs, it just makes most of them easier and faster
A good jack, quality stands and a healthy dose of safety-sense can will allow you do do 99.8% of all jobs that your van will ever require.

At this point I would go find myself a mechanics stethoscope and go over all the usual suspects. If no joy is had, then get it up on stands so that it can safely run in gear without falling on you. You want to listen to things like diff gears, wheel bearings, trans.....
Once you find your culprit, you can strategize the proper repair