My car sounds like a siren

OK Wierd.
Car is 96 Merc Sable S/W w 3.0 engine. It's emitting a noise that sounds just like a siren. It started out as just a humming sound some months ago. I finally got tired of the noise and decided that it must
be the power steering pump, so I replaced it, along with the serpentine belt. (I was careful to bleed the pump.) Immediately the sound increased to a loud siren-sounding noise. I figured it might be a bad replacement pump, so I got another one and put it in. Same thing, just slightly less noisy. The sound is coming from the right front corner of the engine. It is really loud. You can hear my car coming down the road a hundred yards away. Again... it is a high-pitched sound very much like a siren.
BTW, the A/C does not work. But I don't know when it went out. Last time I used it was in September.
Could it be the A/C compressor or clutch? I've never heard one making this kind of noise though. The noise is so loud I cannot pinpoint exactly where it's coming from. I'm a bit worried that it may be an internal problem in the motor itself.
Any ideas?
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46erjoe wrote:

probably a bearing in the idler pulley or tensioner pulley. could be any of the things in the front of the motor(water pump, ac comp,alternator). Use a long screwdriver, one end on your ear, the other near the pulley (CAREFULLY)you think it might be. As bad as it sounds you will find it easily. You can also remove the belt and spin the various pulleys by hand to look for looseness, roughness.
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Yea, what SS said. Thee AC clutch or any other item in front can lock up and break the belt, leaving you stranded. You have waited way past the grace period on this noise.
You could leave the belt on and sound around various areas listening with the handle of a long screwdriver against your ear. This is very effective, yet very dangerious. I would not advise you to do it as you have not done it before. Someone with experience could quickly pinpoint where the noise is coming from.
PS. Just because the AC doesn't work and is never turned on anyway does not prevent that bearing from seizing in front.
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You can use a length of broomstick and touch one end to each of the A/C compressor, alternator, power steering pump, idler, etc. with the engine running, idling, with the emergency brake on.
Check anything that spins with the engine, and put your ear on the other end of the broom stick. The loudest noise is a good indication of a bad bearing on that component. Be sure not to get anything caught in the belt like clothing, hair, jewelry, etc.
I have a mechanics stethescope, but a broom stick, long screwdriver, or similar item can be used. Just stay clear of the belt and pulleys.
Frank

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On Mon, 24 Apr 2006 18:47:44 GMT, 46erjoe

My bet is on the A/C clutch bearing. I/ve had a couple go bad. Almost always eats the node off the compressor. My wife drove the first one a couple of weeks after the noise got bad before she said a word to me.
Lugnut
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If it turns out to be the A/C compressor, is it better (cheaper) to have the mechanic replace the clutch or the whole unit. I got a price on rockauto.com of $200. The clutch is much cheaper but I have to pay labor on the repair. Just wondering what you would do.
Oh... will they have to re-charged?
wrotF:

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On Wed, 26 Apr 2006 02:01:03 GMT, 46erjoe

Both failures I've had ate the nose off the compressor case requiring the compressor be replaced. Yes, it will need to be replaced and recharged if this has happened. The only way to know the extent of damage is to pull the clutch from the compressor. You probably need to access it thru the inner fender panel.
Lugnut

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46erjoe wrote:

Either way you will have to pay the full labor, unless you do it yourself. On your car you will likely have to remove the compressor whether for the clutch or the whole compressor assembly. The AC will have to be serviced also. If the shop follows normal AC service cnvention, don't be surprised if they quote a price for replacing the AC accumulator. It's good practice to replace the 10 year old accumulator when the AC system is opened. It's kind of like the oil filter on the engine, it is a wear item. It "should" be replaced but "can" be reused. (that's the closest analogy I could think of, I don't reuse oil filters and have reused accumulators on occasion) Also, don't expect the shop to use the $200 compressor from Rock Auto. Expect to see ~$300-400 for the part. A reputable shop will use a New compressor and they will see a bit of mark up on the price.
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I'm tring to understand this, we have a 100% failure, it should be easy to isolate. I would soak idlers with oil and anything in the belt system till I found the failed bearing or whatever... Now that we have it that it is coming from the right side of the engine... Pulley system. Once in the position of looking right to left at the passenger side with the engine running is the noise coming from the right or left? Right you have the AC and the PS with the ALT in the middle. You should have an idler directly down between the ALT and the PS. This noise is coming from the left or right as looking from the passenger side front tire? I might be just running my mouth off but it's time to isolate the device...
Gerald
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You said the AC did not work. If it's the AC clutch and you want air then you need to have it fixed. However, if just handling the immediate problem is the objective, they used to make a dummy pulley and bracket that would replace the AC. I can't recall if it was from Ford or an aftermarket supplier. The part was about $50 a few years ago.
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