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Discussion Starter #1
Since new I have heard a slight whirling noise coming from
my left front. It doesn't happen when cold. It will take a couple
of miles to develop. Everything operates fine so it's got me
puzzled. I've eliminated wheel and shaft bearings because it doesn't happen when cold and it's as straight as an arrow. It has not gotten worse in 4 months. Any ideas?
 

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Sound anything like a semi truck's turbo between shifts?
 

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jeffil1965-

Does it change with engine speed? Road speed? When coasting in neutral?

-njjoe
 

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Discussion Starter #4
Thanks guys for responding. It doesn't sound like the semi turbo
(although I hear that when decelerating but I think that is normal)

Is is vechicle speed dependent and starts at about 10 or 15 mph and gets
a little louder the faster you go. Engine RPM has no effect. It almost
sounds like a wind noise but I ruled that out once I realized the
car has to be driven a mile or two before I hear it and it does
gradually come on as it warms. I do hear it before the engine
comes up full temp and before the engine stops running at the higher RPM during warm up. It happens during coasting or acceleration.

My best guess is it's the CVT just making a harmless noise or maybe
I have the hearing of a dog or something.
 

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jeffil1965 said:
My best guess is it's the CVT just making a harmless noise or maybe I have the hearing of a dog or something.
:21:
 

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Discussion Starter #6
njjoe:I took your suggestion this morning and shifted into neutral
while I was traveling about 25 with the engine running and that
had no effect on the noise.
 

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jeffil1965 said:
njjoe:I took your suggestion this morning and shifted into neutral
while I was traveling about 25 with the engine running and that
had no effect on the noise.
From what you have indicated, I would rule out the CVT, transfer case, and CV joints as the source of the noise. If it had been any of those three then the noise should have changed as you got in and out of the throttle.

Since you say it is not engine-speed dependent, you can rule out belts, alternator, water pump, etc.

You already ruled out the wheel bearings.

What rotating mass is left? Tires? Radiator fan? This is a tough one. I don't have a good answer for you. Sorry.

-njjoe
 

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Its probably the motorized motor mount,

Homer
 

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hfelknor said:
Its probably the motorized motor mount,

Homer
Please correct me if I am wrong. The operation of the electronically-controlled engine mount is simple. It can either be set for "soft" or "hard". The default (idle) state is "soft". With the engine warmed up, the ECM will signal the mount to shift to "hard" if the car is moving and the RPMs are greater than 950. It doesn't cycle as long as the RPMs are maintained over 950.

jeffil1965 claims the noise changes with the vehicle speed. That would rule out the mount. Right?

-njjoe
 

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If you wish to assume that it is operating correctly, you are right.

Homer
 

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How about the failing altenator bracket problem?
Mine still buzzes at around 1959-2300 rpm, acording to the load. I'm sure that is what it is in my case. I have yet to have time to get it to the $tealer.
 

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Discussion Starter #12
I tried something else today. At about 30mph, I shifted into
neutral and shut off the engine. No change in the noise until
the vechicle slowed down like always.

Prior to this I have switched the LF and LR wheels. No change
there either.
 

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jeffil1965-

That was a good move, shutting down the engine. Now you have effectively eliminated the engine as the source of the noise.

-njjoe
 

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Given that its not engine related (shutting off the engine while coasting was a good diagnostic step, but not a very safe one - the brakes have one reserve vacuum stop in them, and you have no power steering), or electronic related (shutting off the engine again), it would appear to be a bad wheel bearing. The sound is certainly coming from the correct area. Switching wheels as you have done also rules out a tire issue.

But if its not a wheel bearing, it could be something like a bent brake disc backing plate (the metal shield) - or maybe a rock or debris stuck in between there somehow (hey, I've heard of it happening, rarely). Sometimes the actual answers cannot be found in the FSM!
 

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Discussion Starter #16
Thanks Enforcer for the pic. I have examined the tire and it appears
fine. I've switched tires too and no different. The whirling noise
sometimes sounds like a wind noise as if some external body
part is creating a low pitch whistle. Make sense?

What does a bad wheel bearing sound like? I always assumed
that would be like a metal on metal or grinding sound?
 

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Thats been my experience. The fact that it doesnt happen while cold wouldn't suggest body part wind noise. And since it doesnt happen while cold it probably makes it tough for a dealer to reproduce it. Rather, they probably won't take the time to reproduce it. If you can reproduce it on the way to the dealer, maybe you can arrange for them to get in the car when you get there?
 
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