Mechanic's stethoscope or a long screwdriver as one.
Alternator Bearing Question **Noise Solved**
- Thread starter nick0789
- Start date
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I've been using a long screwdriver to probe around and haven't been able to locate the source, yet. I don't get much time before the noise goes away, and I can't reach far enough into some areas that I'd like to so I'll grab a stethoscope today and poke around in the morning.
corvette744
2004 Z-71
So you cant touch the power steering pump or hydra boost with a long screwdriver? You should be able to reach both those.Long pry bar long extension anything metal and long-piece of rebar lol anything.I just popped my hoodi can touch my ps pump with a long screwdriver and the hydraboost with a short one-should be pretty easy to figure out.
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Have we discussed the water pump?
The longest screwdriver I have is like 14" long. I can reach the hydroboost just fine, and I can touch the PS pump just fine as well, but the issue is getting my head down (or over) on the screwdriver. I'm not 7' tall so I have the logistical issue of cranking the engine, getting up and in position in the engine bay, putting the screwdriver on whatever I'm testing, then leaning down into the engine bay to get my ear on the screwdriver before the sound goes away ... all without slipping off the step stool and ending up getting caught in or on something lol. I may just end up joining together a few socket extensions and go about it that way.
I have a 30" breaker bar that I've tried using in the past as a stethoscope but the sound never traveled well through it so I don't bother with that anymore.
No, not as a potential source at least. Water pump was replaced, new, back in April.
corvette744
2004 Z-71
Gotcha dont hurt yourself lol.I measured my screwdriver its 24 inches works perfect.If you have a harbor freight by you they have a set of 2 that are 22 inches for 4 bucks. https://www.harborfreight.com/2-piece-super-long-screwdriver-set-34253.html
Posting one more troubleshooting update before I throw in the towel and take it to the shop.
To summarize:
- I was able to listen to all the pulleys on the front of the engine and none had a whining noise
- alternator was replaced (preventative)
- power steering fluid flushed
- checked around intake manifold ports, throttle body, and snorkel with carb cleaner at idle and no idle changes were noted
- ran with no belts, just the AC belt, and both belts: noise was present as soon as the main drive belt was reinstalled.
- checked the two vacuum lines from the intake to the valve covers and didn’t notice any cracks or tears.
- the whining sound is present while in park and while driving at around 2,000 rpm. It sounds like a knockoff F1 engine whine a little. I have a couple clips of the whining sound from inside the cabin; if anyone is interested I will try to get the wife to give it a little throttle while I record in the engine bay.
The whine is somewhat faint so I’m sorry if it’s tough to hear but once you hear it you’ll know what I’m talking about.
To summarize:
- I was able to listen to all the pulleys on the front of the engine and none had a whining noise
- alternator was replaced (preventative)
- power steering fluid flushed
- checked around intake manifold ports, throttle body, and snorkel with carb cleaner at idle and no idle changes were noted
- ran with no belts, just the AC belt, and both belts: noise was present as soon as the main drive belt was reinstalled.
- checked the two vacuum lines from the intake to the valve covers and didn’t notice any cracks or tears.
- the whining sound is present while in park and while driving at around 2,000 rpm. It sounds like a knockoff F1 engine whine a little. I have a couple clips of the whining sound from inside the cabin; if anyone is interested I will try to get the wife to give it a little throttle while I record in the engine bay.
The whine is somewhat faint so I’m sorry if it’s tough to hear but once you hear it you’ll know what I’m talking about.
it's really hard to say, typically the only things that make noise like a high pitch or squealing is the belt tensioner and/or idler pulley (the idler sits right next to the alternator), sometimes the ac pump will make noise when they go out but that noise is much more pronounced and quickly escalates into a sound like a food disposal trying to grind nuts and bolts. I hate to have someone just throw money something but if the sound was gone with the belt off then it's likely a moving external part, if it were me I would move on to the idler pulley since the noise from your video seemed to come from that side, the belt tensioner is on the other side, but it's just a guess. maybe invest a couple bucks in a can of lithium spray and try just putting a small spay on the idler pulley bearing and see if it makes any difference just as a experiment? I don't know maybe someone else has an idea I am part idiot so i could be wrong, could be the flux capacitor or something 
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.Sorry, I thought I included that in my update. I replaced the idler pulley over the weekend just to see and the sound is still there. I figured $30 and 3 minutes of my time was worth the gamble.it's really hard to say, typically the only things that make noise like a high pitch or squealing is the belt tensioner and/or idler pulley (the idler sits right next to the alternator), sometimes the ac pump will make noise when they go out but that noise is much more pronounced and quickly escalates into a sound like a food disposal trying to grind nuts and bolts. I hate to have someone just throw money something but if the sound was gone with the belt off then it's likely a moving external part, if it were me I would move on to the idler pulley since the noise from your video seemed to come from that side, the belt tensioner is on the other side, but it's just a guess. maybe invest a couple bucks in a can of lithium spray and try just putting a small spay on the idler pulley bearing and see if it makes any difference just as a experiment? I don't know maybe someone else has an idea I am part idiot so i could be wrong, could be the flux capacitor or something
If I have the AC running, the noise is still there as well.
With the beauty cover off the intake, the sound is definitely louder.
I know the electronic throttle bodies can make a slight whine but the revving of the whining sound at a constant RPM made me think it was a vacuum or some other air leak.
I don’t have any codes, but I do wish I could do some more digging with a TechII
Maybe grab one of those little stethoscope things and see if you can locate it that way I think harbor freight has them
