(Update on post 18) Whats wrong with my Alternator?

[SHOspazz92]

I just Finially got my car back this morning and what my dad thought to be a noise coming from a PS pump is actually coming from the alternator. The thing is holding a charge perfectly fine and the car runs great, But it sounds like a freaking Air Compressor is running in perfect snyc with my engine's RPM's. So whats going on here?

-Sam

 

[93rev2sev]

Get a digital volt meter and a cig lighter power adapter...hook the 2 together and monitor the alternators output.

It should be a rock solid 13.5-14.2V (or there abouts)

 

[SHOspazz92]

Get a digital volt meter and a cig lighter power adapter...hook the 2 together and monitor the alternators output.

It should be a rock solid 13.5-14.2V (or there abouts)

Im not to much worried about the output as I am the very Audible and Horrid noise coming from under my hood. I swear to go it sounds like I have a loud ass air compresser running under there.

-Sam

 

[93rev2sev]

Well then, it sounds like you've answered your own question...

Q: What's wrong with my Alternator...

A: It's a loud ass MF!

 

[SHOspazz92]

Well then, it sounds like you've answered your own question...

Q: What's wrong with my Alternator...

A: It's a loud ass MF!

Ok... So obviously the two can be related. I'm anxious for this car to be running perfect so sorry if I come off like a dick. This sucks as this alternator was just replaced about 10 months ago.

-Sam

 

[93rev2sev]

Well, is your A/C compressor belted or bypassed?

 

[gmorrell]

Could be bad bearings or noisy slip rings for the field coil. Have you tried removing the accessory belts, one at a time, then running the engine for a bit to isolate the noise?

Got an engine stethescope? These are handy for tracking mechanical noises. In a pinch, use a long screwdriver as an acoustic probe - place the handle against your ear, use the tip to pick up noise from stuff. (Caution: The screwdriver technique works poorly with the tip in your ear... )

Rare: Could be a loose diode in the rectifier pack. I've seen this just once in 40 years of working on cars. The diode would vibrate at the AC frequency coming from the stator coil, and alternator output frequency tracks RPM. Said loose diode eventually failed because it was poorly attached to its heat sink and over heated.

 

[shoshirtsandhat]

Take it off & take it back where it was purchased and have it bench tested, my alt has a lifetime warranty>ADVANCE,,,take it back !

 

[SHOspazz92]

Take it off & take it back where it was purchased and have it bench tested, my alt has a lifetime warranty>ADVANCE,,,take it back !

The car was had the alternator put on while I was in Japan, It was done in California. I just recieved the car this morning in NC... So... Not an option, I'll look in these options on Friday when I have some time off. I appreciate everyones input very much!

-Sam

 

[SHOspazz92]

Also, The A/C Compressor is belted.

-Sam

 

[SHOspazz92]

Well, After taking a "Closer look" I dont beleive its the alternator. This really sounds like its more coming from the Water pump. A screwdriver as a stethoscope confirmed this. The alternator itself does not sound the healthiest (Sounds like the bearing on the pulley is going) but this is definently coming from the PS pump... This is not going to be cheap.

-Sam

 

[Shoaz]

Well, After taking a "Closer look" I dont beleive its the alternator. This really sounds like its more coming from the Water pump. A screwdriver as a stethoscope confirmed this. The alternator itself does not sound the healthiest (Sounds like the bearing on the pulley is going) but this is definently coming from the PS pump... This is not going to be cheap.

-Sam

Water pump or PS pump?

The water pump was replaced with a new OEM unit at ~80k miles.

 

[SHOspazz92]

Water pump or PS pump?

The water pump was replaced with a new OEM unit at ~80k miles.

Its definently coming from where the Water pump is, Weather its a bearing or the actual unit itself I can't tell. The PS pump seems to be fine as it makes hardly an Audible noise when the wheel is being turned at low speeds or from a Idle. This noise is perfectly in snyc with engine RPM and is VERY Loud.

-Sam

 

[Storm-Chaser]

Are you sure it's not the timing belt tensioner . . . ?

 

[gmorrell]

Its definently coming from where the Water pump is, Weather its a bearing or the actual unit itself I can't tell. The PS pump seems to be fine as it makes hardly an Audible noise when the wheel is being turned at low speeds or from a Idle. This noise is perfectly in snyc with engine RPM and is VERY Loud.

-Sam

One of the idler pulleys perhaps?

Have you pulled the belts one at a time to narrow down to at least a pair of accessories?

 

[SHOspazz92]

One of the idler pulleys perhaps?

Have you pulled the belts one at a time to narrow down to at least a pair of accessories?

I'm not going to be able to do that until this weekend due to a Major Exsercise thats going on all week on base. But, I definently will. I'm absolutely terrified to drive this thing but I am stuck in a situation this week to where I have too, So... On saturday its game on.

The car is running fantastic. All the power is there but with this noise this thing is making it just scares me. The worst part about it is is just how audible it is, I've never heard anything like it. When I say this thing sounds like an Air Compressor I'm not even stretching the truth one bit. In anycase, If you have ever heard the air compressors on on a 90-94 or so lincoln continental from the inside of the car when it fills up the airbags thats exactly what it sounds like, Except its all the time.

-Sam

 

[SHOspazz92]

Just in case... Does anyone know the Part # for the accessory belt to bypass the A/C? I'm not saying thats the problem but the A/C has been acting up lately so you never know. I am just looking for the PN to have for reference. A Search on the forum only came up for a ATX Serpentine belt.

-Sam

 

[SHOspazz92]

Ok, So today I took off the Accessory belt to the A/C and Alternator, Started it up and the noise was completely gone. Once I had the belt off, the Idler Pulley and A/C compressor made no noises when spinning them by hand so I am going to assume its my alternator. However, Once I put the belt back on and made sure everything was tight the noise is different. It no longer sounds like an Air Compressor but more so makes a whining type noise.

I also noticed somthing else that could be causing these noises all together. The two long bolts that are 8mm (IIRC) that are on the housing of the Alternator, One near the Intake Manifold Brack and one near the coolant resevoir were both completely backed out. It does not even look like there was any kind of Loctite or what not put on them from the factory. This Alt. has only about 15,000 Miles on it so it will be replaced as wherever it came from obviously has some QC issues.

Either way, I'm glad I did it myself and oddly enough the longest part of this was getting that damn battery tray out (Long story).

-Sam

 

[okcoolthnx]

I just had the same problem on my ATX. Turns out it's the Accessory belt tensioner pulley. The spring loaded one in between the PS and Alt and above the Water Pump. Finding the part new is impossible so I just went to a junkyard and pulled like three of them. As soon as I changed it, the SHO ran like a brand new motor. SOOO much quieter....