My truck has developed this whining noise that makes it sound like it has a supercharger under the hood. It increases with revs and it probably there at all revs, but I can only hear it at low speed and low revs... then engine and road noise tend to drown it out. I haven't gotten dirty yet trying to diagnose it, but was hoping somebody could give some suggestions as to what to look at. I'll definitely check the condition of the belts as it sounds like the noise might be coming from the alternator area of the engine bay.

Has anybody experienced the bearings going bad on an idler pulley or an alternator? Could you describe the noise? Anything else I should be focusing on? No engine codes that I can see at this point.

 

Could be all of the above but that is exactly what my later atop sounded like before it went.
It went quick too.

 

I have no idea wtf a "later atop" is but my alternator sounded like a bad power steering belt when it went ****. Not unlike the EPB actuator whine but nowhere near as intense.

Also, if you are hearing it with the climate control on, try turning it off and see if the whine goes away. Mine was doing that, and then I had the system flushed and re-charged. After a few cycles the whine is gone.

 

Lol. I'm going to guess "later atop" is some form of auto correct for alternator. Thanks both for the replies. I have a feeling that's what my issue is... perhaps not alternator, but some form of pulley bearings. Though it sounds like it's coming from the alternator location, so that would be my first guess.

I also had a higher pitched whine that I could tell was coming from my blower motor. Finally took the thing out and lubed it with some garage door lube. Put it back in and everything seems fine (it's amazing how much carbon dust had accumulated from the brushes). That's why the first thing I did was shut the climate control off, but the new sound was definitely still there.

Oddly enough, the sound has persisted for a week and a half or so, but I got in this morning and it was gone. So... I will continue to ignore it and pretend like it never existed for now. :P

 

Our alternator was whining the same way before it choked last week. Years ago I learned from an old mechanic that a long screwdriver works great as a stethoscope with the handle against your ear for diagnosing "whines"

 

Ah great. So, you're telling me the "ignore it and pretend like it never existed" route doesn't work? I guess I should start tearing into it and give it a good diagnosis before I end up on the side of the road needing a new battery along with the alternator.

 

Damn Auto correct.Lol

 

I have a whinning noise coming from my LR3 that increases/decreases with RPM's. Stops when I turn off climate control. Is this what you blower was doing?? Easy fix?

 

No, my blower noise changed with the fan speed control on the HVAC unit. If your whine is changing as a result of engine speed, then I might suspect what Houm was talking about... a/c compressor low (or high) on refrigerant. However, blower motor is pretty simple to drop and clean/lube.

 

Yeah go get it checked out, @Dirt Roamer; that is what mine was doing. It was a fairly cheap fix. $89 at the dealership but that isn't the book price. They hook me up on the regular. Still not bad though...under $200 and they will let you know if you have a leak in the HVAC system.