What's an alternator going bad sound like?

[CP]

Something has begun making a loud noise on startup. It only happens for 2 seconds, and sounds like a bad caster wheel on a grocery cart. It doesn't dissipate, but stops altogether after the first few seconds of a cold startup. Is it the alternator getting ready to take a dump, or something with the power steering pump?

(Hating my car more and more this winter...)

 

[VR4coop]

I would say power steering fluid. Make sure it is full. If you have put any additives in the fluid this may also be causing the sound, as it may be very thick.

 

[mikus]

my harmonic balancer had this symptom b4 seperating....

 

[toybreaker]

Fwiw, my tsi will occaisionally sqwauk a bit when it's really cold out. (like -10*f)

In my case, it's the accesory drive belts protesting the load at startup.

The alternator is trying to jam 50amps back in the battery, and the power steering fluid is cold, and therefore, very thick, and hard to pump.

The belt tension is ~correct~, and any further tightening will just stress the alternator and water pump bearings

Check the alternator and power steering belt tension.

Put a paint/witness mark across the harmonic balancer, from the inner hub to the outer ring. Check it's alignment after it makes the noise.


I've resigned myself to dealing with it, but I will share one trick that works well for me, and eliminates any problems till it get's really cold.

After the belts have been slipping for awhile, there's almost no wat to make it stop. You can apply so much tension to the belt that you're killing bearings in the water and power steering pumps..and it still squeels. Hang a new belt...and it still squeels...

That's because because the pulleys are glazed/polished, and they can't develop any traction on the drive belt.

When you have the pulleys off during maintainance, give them a light blast in the pulley groove area with a glass beader. A light beading will roughen the grooves, and give their surfaces some "tooth" Usually, that's enough to let you run a ton less belt tension, and stop the squeeling at start-up.

On the original question, an alternator going bad will have a couple of different potential noises.

A "rumble" means alt. bearing issues. Put a mechanics stethescope on the case, and that will tell the tale. (a long screwdriver works as well. Just place the tip against the case, and listen at the handle)

A high pitched whiring/whining noise that changes with load, and follows the engine rpm may very well be a bad diode, or a problem in one of the windings. You can often here this on the am band of your radio as well.

A /ubbthreads/images//graemlins/bawling.gif noise is the owner at the dealer buying a new one...

A /ubbthreads/images//graemlins/mad.gif noise is someone returning yet another junk rebuild /ubbthreads/images//graemlins/banghead.gif, to checker/autozone etc...

A /ubbthreads/images//graemlins/grin.gif noise is someone buying a good, (non-rebuilt) core from a galant at the boneyard for ~$10 to ~$25, and rebuilding it with new brushes and a regulator.

Look for a how-to in the coming weeks. /ubbthreads/images//graemlins/wink.gif

 

[CP]

The PS fluid is new and full. I suck the reservoir dry and refill it with Mobil1 auto tranny fluid at every oil change.

I've got new belts to install later this month, but I know it's not the belts squeaking. The harmonic balancer is a 2G unit that was used to replace the stocker during a timing belt change 18 months ago. I'll inspect it and mark it up to watch for slippage. Guess it's time to make a stethescope out of some brake line soon.

 

[Rausch]

^ Just use a screwdriver. Ear on the handle works very well. They sell a mechanic's stethescope at Harbor Freight for like $5, if there is one close to you.... /ubbthreads/images//graemlins/grin.gif

 

[steve]

Quote:
I suck the reservoir dry and refill it with Mobil1 auto tranny fluid at every oil change.



PM sent. /ubbthreads/images//graemlins/hsugh.gif

 

[14u2nV]

Sounds like an alt belt to me. Swap it out ($9) and see if it stops.

 

[JB]

Quote:
Quote:
I suck the reservoir dry and refill it with Mobil1 auto tranny fluid at every oil change.



PM sent. /ubbthreads/images//graemlins/hsugh.gif



wtf...

 

[HHIVR4]

Quote:
my harmonic balancer had this symptom b4 seperating....



me too

 

[ApexHunter]

Quote:
my harmonic balancer had this symptom b4 seperating....



what happened when it separated? i'm concerned because i have a similiar noise that seems to be coming from the accessory drive belt region, it sounds kinda like if you put some small rocks in a blender on low speed.

 

^^if you are really lucky, like run right out & buy the winning lotto ticket lucky, it will fly off & throw the belts. the design if the thing tends to propel it into the lower cover though & next into the timing belt.

look at it with a flashlight while the engine is running, if you see it wobble at all, replace it. You can also remove the dust sheild from the wheel well & mark accross the face of it & then drive around a bit & see if it is walking, they don't all start to wobble right off.

 

[brisvr4]

Here's something to ponder.
I had a similar sound on some cold starts and I tore my hair out trying to work out what was stuffed.
Changed belts, marked the harmonic balancer, tried spraying belt dressing on it.
I finally got a mate to have a listen to the noise and we found that it was actually a buggered starter motor.
Sounded EXACTLY like a belt squeal on start up.
Something to keep in mind though.

 

[ApexHunter]

Quote:
^^if you are really lucky, like run right out & buy the winning lotto ticket lucky, it will fly off & throw the belts. the design if the thing tends to propel it into the lower cover though & next into the timing belt.

look at it with a flashlight while the engine is running, if you see it wobble at all, replace it. You can also remove the dust sheild from the wheel well & mark accross the face of it & then drive around a bit & see if it is walking, they don't all start to wobble right off.



ha! i won't be that lucky. i'll check it out. thanks. what's weird is the sound gets quieter and sometimes goes away all together after the car has been driven for 30+ minutes.

 

[CP]

Quote:
it sounds kinda like if you put some small rocks in a blender on low speed.



...or pebbles in a metal tennis ball can and spun it around like the motion a clothes dryer exhibits.

That's exactly what mine sounds like. But again, it only happens during a cold start-up and lasts for a second or two just after the engine fires. I took some video this morning, but you can't hear it very well. I'm going to record again when I start this afternoon to head home.

So the consensus is that it's most likely the harmonic balancer?

 

[CP]

Just talked to JNZ and Eric said it's probably the starter. Something about it not disengaging quick enough. He said his car has been doing it for 6 years and it's fine.

I'm gonna mark up the balancer in a day or two once it warms up a little. The stocker runs around $110.

 

[ApexHunter]

^^ that's interesting about the starter. so i'm gonna admit ignorance here for the sake of the car - is the "harmonic balancer" the crank pulley? or is it the pulley above and slightly left of that one (leaning over the driver side fender and looking down)?

 

crank pully

 

[CP]

Crank pulley is the big one at the bottom. That other one above it and slightly to the left is the water pump.

 

[ApexHunter]

Quote:
^^if you are really lucky, like run right out & buy the winning lotto ticket lucky, it will fly off & throw the belts. the design if the thing tends to propel it into the lower cover though & next into the timing belt.

look at it with a flashlight while the engine is running, if you see it wobble at all, replace it. You can also remove the dust sheild from the wheel well & mark accross the face of it & then drive around a bit & see if it is walking, they don't all start to wobble right off.



thanks IslandVr4 and CP for helping me identify the balancer. Island, when you say "see if it's walking" should i look to see if its moving towards the front/back of the car, up to the sky/down to the ground, or in towards pass. side/out towards driver's side?