High pitched whine

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EvkoOffroad

EvkoOffroad

10 Year
Joined
Sep 1, 2015
Threads
3
Messages
109
Location
Bozeman, MT
Hello everyone. As this is my first post let me say hello, and also say thank you to all of the helpful threads that I have looked at!

First my rig:
1998 Land Cruiser with 250,000 miles. I just purchased the cruiser about a month ago and I am loving it. Can't wait to get out on the trails. I joined the tlca and the local chapter here in town. I was even able to make the September member meeting. There are a few upgrades here and there on the cruiser, but I'll get to those later.

Now the current issue I am having:
There is a constant engine whine that I can't seem to track down. I thought it might be the power steering pump (thanks to some suggestion on mud). I changed out the power steering fluid with the recommended mobile 1 atf, but it didn't help the noise. The whine seems to be coming from the front of the engine. The whine changes to a higher pitch when accelerating, either in drive or neutral. The whine isn't affected by the a/c being on or off. The whine has been present in both 80 degrees and 50 degrees. The serpentine belt seems nice and tight, so no slipping.

Here is a video of the whine:


If there is any other information that you guys might need, please let me know.
 
Alternator dying a slow painful death? Mine made a similar sound until I finally ripped the old one out and put a new one in. Check your charging rate with a voltmeter, had mine checked at the old dealership I worked at and it was lower than normal.

Take another video and goose the throttle in front so we can hear what it sounds like when it changes.
 
I crawled underneath the cruiser just to take a quick look and noticed that it looks brand new. I'll have to check the voltage in the am, but I am wondering if it is something else.
ImageUploadedByTapatalk1442466437.329631.webp
 
Hmmm... could also be one of the bearings in one of the pulleys.
 
Welcome! It sure sounds like a dry bearing. If you remove the serp belt and spin all the pulleys and tensioner by hand, I'll bet you find one that's rough and tight. Some use a stethoscope on bearings while the engine is running but that scares me.
 
That's a good idea to turn them by hand. I probably won't get to it until this weekend as this is my dd. Does it take a long time to take the serpentine belt off? Or is it relatively easy to loosen the tensioner and remove the belt?
 
So I tested the alternator, no issues on power. Then I used a piece of wood to act as a stethoscope to listen to the pulleys. All seemed to check out. Put it on the back of the alternator and sure enough, it is the problem child. Strangely enough, when I had the wood on it, it quieted down. I pressed against the back of it, and the noise was almost gone. So weird. So I am now thinking the new alternator that the previous owner put in it is working fine, but the shell around it is rattling which is making the whining? In which case I'll try to tighten up the casing around it? Or do you guys think the alternator needs to be replaced? Thanks again for all the help so far.
 
EvkoOffroad said:
So I tested the alternator, no issues on power. Then I used a piece of wood to act as a stethoscope to listen to the pulleys. All seemed to check out. Put it on the back of the alternator and sure enough, it is the problem child. Strangely enough, when I had the wood on it, it quieted down. I pressed against the back of it, and the noise was almost gone. So weird. So I am now thinking the new alternator that the previous owner put in it is working fine, but the shell around it is rattling which is making the whining? In which case I'll try to tighten up the casing around it? Or do you guys think the alternator needs to be replaced? Thanks again for all the help so far.
Click to expand...

Are there any markings on the alternator to indicate if it is a Toyota factory part or a generic replacement unit? Any history on the LC that tells you how many miles are on that one? OEM alternators seem to last a long time, so I'm suspicious that someone may have swapped in a "cheapie" to save a few bucks.

I agree that a properly charging alternator doesn't prove anything. A bad bearing is a bad bearing....and it will squeal until you replace it.


-G
 
It was the alternator pulley that was making the noise. I replaced it, and the whine is gone. Pretty easy to do, there are instructions for replacement somewhere here on Mud. I have a 1998, so I had to also remove the power steering pump pulley in order to remove the alternator.
 
Thanks, what did it sound like from inside the cabin? A slight whine that you could hear at low rpm less than about 30mph at which point ambient noise surpasss it?
 
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