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High pitched whistle varies with rpm?


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1990 Loyale 5 spd FWD FYI

 

Anyone experienced a whistle noise, like a tea kettle, but 1/2 that loud, that increases in pitch with RPM? At idle, nothing, start maybe 2k rpm you hear it a little, 2500-3000 more, 3500 higher pitch same volume. Coast with the clutch in, nothing. Sit still, rev engine, whistle occurs. Something on the engine. Pretty annoying at 70 mph you hear this "weeeeee" in the background. Not a radio or speaker issue either, radio on or off no effect, independent. Almost like a big diesel truck turbo whistle, spools up and down with rpm, but since my Loyale has no turbo...umm...:confused:

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Altenators will do that. Don't mean thy're bad, or going bad. They'll just do it.. Really irritating when it comes over the stereo speakers.....

 

edit;

 

Another cause could be either a vacuum leak, or an exhaust leak. Both can cause a whistle of sorts.

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This does not seem to be coming from the radio speakers at all. Happens when the radio is on or off. If you roll the window down, and kind of stick your head out, you can hear it a lot louder than when you are inside with all the windows up, but you can hear it either way, fairly loud, louder than any car I've ever had and I've had a fair number. Thanks for the reply, though...I was thinking vac leak myself. It is a real clear, apparent whistle, more so than a whine if there is a difference. Really, the more I think about it just like a semi running beside you on the highway and you hear that turbo spool up. This follows engine rpm linearly, though, unlike a turbo, which is running independent of engine rpm and on exhaust volume instead.

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If the engine has a clutch fan behind the radiator, check all the blades on that. If some are worn out or broke it may make funny noises.

 

And throwout bearings like to whistle when they go out. Usually you can tell its a throwout bearing if the sound goes away with movement of the clutch peddle.

 

-Brian

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Thanks, I will check those things. I doubt if it is clutch-related, since when you push the clutch pedal while driving the noise subsides and changes pitch as rpms fall, and the noise is there at steady highway speeds with clutch engaged, and in the driveway with clutch disengaged sitting still when you rev the engine.

 

I think when it warms up outside I can get the wife to help ( yeah, she loves crap like being a helper on a stupid car project heh heh ) and have her run the rpms up and down while I poke around under the hood and see if I can pinpoint where exactly the noise is emanating from.

 

I do appreciate all the replies with good things to consider. I was hoping for the magic bullet, like, oh, yeah, newbie, all the Loyales do that and everyone knows it, here is what it is...

 

umm, yeah, right, like it is that easy :D

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Could be all that has been suggested also does it have A/C if so they have an idler to adjust the belt tension and they make this sorta noise when they start to go disconnect Air Con belt and see if it goes away..

 

Does have A/C, interesting idea, I will eyeball and give a listen when I can enlist the wife as a throttle operator. Good idea, I would not have thought of that.

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Could be all that has been suggested also does it have A/C if so they have an idler to adjust the belt tension and they make this sorta noise when they start to go disconnect Air Con belt and see if it goes away..

 

Wonder if you could get some goo to lube the idler slightly & temporarily which may change the noise or make it go away to isolate it...

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Also, check the timing belt tension, and the little bearings on the idlers. Make sure the belts are tracking correctly, not rubbing on things they shouldn't. Every time I have heard those kind of strange noises from the engine area, it has either been an idler bearing, alt. bearing or lead to a broken timing belt.

 

I use a piece of 1/2" hose as a stethoscope to probe araound. Also, a long screwdriver touching things with the handle end pressed on the bone forward of the ear hole can help discover the source of bearing noise. Sometimes the screwdriver works better than the tubing, sometimes the other way around.

 

Be careful of the alternator fan with the tube, and any moving part with either method. THINK carefully about what is moving, etc. before actually doing these tests.

 

Dave

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Stop by a Napa or equivelent and get a 24" peice of 5/8" heater core hose. Put an ear plug in one ear, and use the hose to pinpoint where the noise is comming from under the hood with the other ear. Works great.

 

Typical whining parts are: Alternator, Water Pump, Power Steering, Timing belt tensioners and the idler, Clutch release bearing.... All of the things with bearings in them basically.

 

GD

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Stop by a Napa or equivelent and get a 24" peice of 5/8" heater core hose. Put an ear plug in one ear, and use the hose to pinpoint where the noise is comming from under the hood with the other ear. Works great.

 

Typical whining parts are: Alternator, Water Pump, Power Steering, Timing belt tensioners and the idler, Clutch release bearing.... All of the things with bearings in them basically.

 

GD

 

Excellent, and thanks, GD, DT, and sm85. All valid points, and the stethoscope ideas are outstanding...if I don't go insane and drive into a wall from the noise on the way to the store, I will implement the ideas. If it was a rumble, or clicking, or something, but it is the one pitch of whistle that is the most annoying to little parts inside the human brain. I don't think you could engineer a more annoying tone.

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Excellent, and thanks, GD, DT, and sm85. All valid points, and the stethoscope ideas are outstanding...if I don't go insane and drive into a wall from the noise on the way to the store, I will implement the ideas. If it was a rumble, or clicking, or something, but it is the one pitch of whistle that is the most annoying to little parts inside the human brain. I don't think you could engineer a more annoying tone.

 

Hehe - there was a semi-conductor factory located next to a chicken farm a number of years ago. Chickens kept dying mysteriously, and acting really weird. Turns out the factory was producing an ultra-high frequency that happened to coincide with the resonance of the chicken skull cavity. Be glad your Subaru is not capable of this feat....

 

GD

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Hehe - there was a semi-conductor factory located next to a chicken farm a number of years ago. Chickens kept dying mysteriously, and acting really weird. Turns out the factory was producing an ultra-high frequency that happened to coincide with the resonance of the chicken skull cavity. Be glad your Subaru is not capable of this feat....

 

GD

 

Excellent story. Maybe it is, and after a certain amount of exposure my head will explode. Well, my wife will sure get a surprise if it happens when I am under the hood and she revs the engine and the whistle gets loud enough and I am close enough to where it finally zaps me...:eek:

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  • 12 years later...

AAAAAHHHHHH!!! What happened? Am I soon to be doomed to the same fate??

I isolated mine to 4 places.. and only those places.. they all have the same brain slicing frequency!!!

Via Screw Driver 

1. Thermostat housing

2. Intake manifold

3 A/C Compressor 

4. EGR Valve 

Speak to me from the past!!

Upon cold start it is not immediately detectable until a minimum of 2min. Most times it's a constant whistling, while intermittently it will not. Which is amazing! I can only say it resembles close to a deer whistle on the highway and the sound track to The Good Bad and The Ugly while shifting through the gears. 

I will speculate to say it's probably my water pump even though listening by ear the bearing don't sound abnormal and it really doesnt have much play on the shaft and it's not weeping, Temp remains in its usual spot goes up then goes down, Heat/Defrost works well. All hoses are hot and there is circulation. All this seems to have happened with in 3 weeks of substitution the 90deg coolant tube at the back of the Port injector to the heater hose. Which I have replaced recently with a molded 90 deg. So either.. I still have a massive Air Pocket and or one of those items mentioned above. Or who's Fricking knows the thermostat is vibrating? 

 IT IS NOT.. pulleys, idler pulley, TB tensioner pulley, power steering, alternator, wheel bearing, etc 

Edited by Len Dawg
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I used a screw driver methodology

 I checked at higher rpm, when it is detectable..

alternator... sssckkggg 

A/C unit .....eeeeeeeeee

Pwr Strng.....sssckkggg 

Thermo Hsng...eeeeeeee

EGR Valve ....eeeeeeee

Intk Mnfld... eeeeeeee

Oil fill cap ... sssckkggg 

Radiator ... sssckkggg 

Bell housing... sssckkggg 

SPFI....          ssshhhhh

Air filter box... ssshhhh

I checked these same places at idle and nothing... even though few far and in between at idle there will be a harmonic whoo oho oho hoouu.. then it stops 

 

 

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Bad bearing screech in the compressor could be carried by the manifold.  This is why the hose method along with the screwdriver method is helpful.

Removing the accessory belts will also confirm / reduce the number of possible sources.

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Dude!! When I shift gears from a stop light people on the sidewalk move a side, because the whistle' is strikingly similar to The good bad and the ugly except at a high pitch whistle.:headbang:weEeEeEEeee !! And you fill in the wuha wuah wauua 

1st weEeEeEEeee

-wuha wuah wauua 

2nd weEeEeEEeee

-wuha wuah wauua 

3rd weEeEeEEeee

And then it sounds like a tea kettle/deer whistle

 

Edited by Len Dawg
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