whirring sound for alternator
#1
05-14-2009, 10:17 PM
whirring sound for alternator
2001 protege w/2.0L 98900 mi . whirring sound just started today at a stop light.
the sound was also accompanied with a burning smell. I think the alternator just
died. when I got back to home, the meter read 12 volts on the battery. The charger went to 6 amps when first connected , and stayed there too long, I priced alt at auto store, now I'm worried, $225.00 and not until 5/23 !!!!!! It is late in the evening, check other sources tomorrow. Is there a way to test alternator to check I'm guessing right?
thanks in advance
the sound was also accompanied with a burning smell. I think the alternator just
died. when I got back to home, the meter read 12 volts on the battery. The charger went to 6 amps when first connected , and stayed there too long, I priced alt at auto store, now I'm worried, $225.00 and not until 5/23 !!!!!! It is late in the evening, check other sources tomorrow. Is there a way to test alternator to check I'm guessing right?
thanks in advance
#2
05-15-2009, 12:28 PM
A good alternator will put out over 13.5 V into a charged battery with the engine at a fast idle (~1500 rpm). A word of caution: don't make the call on the alternator until
(a) you're sure it's hooked up to a good battery (over 12.5V, engine off, with no load), and
(b) that your alternator drive belt condition and tension are correct. A burning rubber smell is often due to drive belt slip rather than an alternator failure.
(c) your battery terminals and chassis grounds are clean and making good contact.
The two most important ones are the one connected to the main grounding plate that the battery negative cable goes to, and the engine block ground connected to the passenger side engine mount.
If you couple a good alternator to a battery whose no load terminal voltage is below 12V, the alternator excitation will not be sufficient to kick the alternator into life; a lot of good alternators have been condemned to the scrapheap just because they were installed on a car whose battery was below par, and hence wouldn't excite.
(a) you're sure it's hooked up to a good battery (over 12.5V, engine off, with no load), and
(b) that your alternator drive belt condition and tension are correct. A burning rubber smell is often due to drive belt slip rather than an alternator failure.
(c) your battery terminals and chassis grounds are clean and making good contact.
The two most important ones are the one connected to the main grounding plate that the battery negative cable goes to, and the engine block ground connected to the passenger side engine mount.
If you couple a good alternator to a battery whose no load terminal voltage is below 12V, the alternator excitation will not be sufficient to kick the alternator into life; a lot of good alternators have been condemned to the scrapheap just because they were installed on a car whose battery was below par, and hence wouldn't excite.
#3
05-15-2009, 08:55 PM
Update on whirring alt. 13.6 v to batt @ 1500RPM . Battery reads 13.0v with no load .
Alternator belt just replaced 2 wks ago (approx 1" deflection) . The burning smell was noticed just after whirring sound started at stop light. Cleaned all batt terminals and main grding plate and engine grd at engine mount. Checked batt this afternoon at lunch, reading was 13.0v.
All checks out like things are normal , but the whirring noise is still there ???
HHmmmmm...........
City driving makes up the bulk of my driving, go to one business ,repair copier and so on for as long as there are service calls to complete. Air conditioning is controled by a thermstat. It's been 60 - 70 degrees in the afternoon . This means an extra load on the electrical system of the mazda . Can the alt burn up a bearing on the pulley shaft , not to freeze the shaft but make the bearing make more noise as it spins ???? I don't know how an alternator is built. Possible ???
Alternator belt just replaced 2 wks ago (approx 1" deflection) . The burning smell was noticed just after whirring sound started at stop light. Cleaned all batt terminals and main grding plate and engine grd at engine mount. Checked batt this afternoon at lunch, reading was 13.0v.
All checks out like things are normal , but the whirring noise is still there ???
HHmmmmm...........
City driving makes up the bulk of my driving, go to one business ,repair copier and so on for as long as there are service calls to complete. Air conditioning is controled by a thermstat. It's been 60 - 70 degrees in the afternoon . This means an extra load on the electrical system of the mazda . Can the alt burn up a bearing on the pulley shaft , not to freeze the shaft but make the bearing make more noise as it spins ???? I don't know how an alternator is built. Possible ???
#4
05-16-2009, 07:15 AM
Sure is possible; and those belts are grooved and heavily loaded (the alternator alone takes about 1.5 H.P. through its small diameter drive pulley).
When the belts are changed, they have to bed in on the pulley grooves,which unless they have been cleaned, are full of the residue of the worn belts they replace, so they have to bed in for a couple of weeks, then be checked and retensioned. There is also an idler pulley there which can be noisy. Try squirting a small amount of graphite based lube into the center area of it.
Under no circumstance put a lubricant of any kind on those belts though, so use a cloth to protect them from any drips.
When the belts are changed, they have to bed in on the pulley grooves,which unless they have been cleaned, are full of the residue of the worn belts they replace, so they have to bed in for a couple of weeks, then be checked and retensioned. There is also an idler pulley there which can be noisy. Try squirting a small amount of graphite based lube into the center area of it.
Under no circumstance put a lubricant of any kind on those belts though, so use a cloth to protect them from any drips.
#5
05-16-2009, 07:25 AM
Sure is possible; and those belts are grooved and heavily loaded (the alternator alone takes about 1.5 H.P. through its small diameter drive pulley).
When the belts are changed, they have to bed in on the pulley grooves,which unless they have been cleaned, are full of the residue of the worn belts they replace, so they have to bed in for a couple of weeks, then be checked and retensioned. There is also an idler pulley there which can be noisy. Try squirting a small amount of graphite based lube into the center area of it.
Under no circumstance put a lubricant of any kind on those belts though, so use a cloth to protect them from any drips.
I forgot to mention an important item. When you are using your A/C, there is an electric fan (the one behind the rad. on the lower driver's side. The noise you're hearing is probably just that, so between the belt residue issue I mentioned, and the A/C electric fan, it sounds as if you're good to go ZOOM ZOOM;your electric system volt numbers are just fine by the way.
When the belts are changed, they have to bed in on the pulley grooves,which unless they have been cleaned, are full of the residue of the worn belts they replace, so they have to bed in for a couple of weeks, then be checked and retensioned. There is also an idler pulley there which can be noisy. Try squirting a small amount of graphite based lube into the center area of it.
Under no circumstance put a lubricant of any kind on those belts though, so use a cloth to protect them from any drips.
I forgot to mention an important item. When you are using your A/C, there is an electric fan (the one behind the rad. on the lower driver's side. The noise you're hearing is probably just that, so between the belt residue issue I mentioned, and the A/C electric fan, it sounds as if you're good to go ZOOM ZOOM;your electric system volt numbers are just fine by the way.
#6
09-23-2009, 10:24 PM
the alternator finally gave out. Car ran off battery, and died in walmart parking lot. Thank goodness for friends, gave me a jump and car started doing whacky electrical things. engine died shortly after removing jumper cables. Friend jumped started car again after letting batt charge off his truck. The short drive home was all the batt would allow me. Next day , replaced alternator (loose the remove bolts on top, 12mm, remove alternator from bottom . disconnect battery BEFORE STARTING, and install new alternator in reverse order .
Johnmike , change the alternator now , because , when it quits charging battery you need tow or a good friend to get car home. Changing alternator took approx 2 hrs.
good luck
Johnmike , change the alternator now , because , when it quits charging battery you need tow or a good friend to get car home. Changing alternator took approx 2 hrs.
good luck
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