Knocking/Clunking Alternator???

[fullahotair]

My engine has an intermittent knock/rattle at idle (haven’t driven’t the car yet, so I can’t say what does while driving). It sounds like it is coming from the alternator. If I put a screw driver to my ear and to the altenator, it certianly sounds like that is the source of the noise…So my question is if anyone has heard of a clunking/knocking alternator?? or might it be emanating from somewhere else….

I suppose I could take it off, and take into the parts store to test and see if they can get to knock/clunk…

Thanks,
Nate

 

[fullahotair]

maybe its the tensioner and it is resonating up through the alternator?? just another idea...

 

[wickedtt]

maybe its the tensioner and it is resonating up through the alternator?? just another idea...

I have seen both just take the belt off and spin the alt. and see if it is binding or noisy..

 

[salvageV6]

Yep, take the drive belt off first, spin the alternator and spin the tensioner pulley, see which one if either have any noise or sticky bearings that are shot in them. Obviously they both should spin very smoothly.

 

[fullahotair]

I'll try that tonight..thanks.....when bearings go bad, don't they usually squeal? If it is a shot bearing, i just haven't heard many knock/rattle...



Thanks again...


Nate

 

[salvageV6]

It could be the tensioner spring itself, check for decent tension and smooth movement when operating it. An internal break could make that sound.

Could also be a cracked housing I guess as well, metal on metal sound.

 

[83ttypecooled]

Hi,
I agree. Try any other possibility before you do this one, Good luck with your issue.

 

[fullahotair]

Does your tensioner move back and forth slightly when you car is idling, or does it essentially stay stationary. I did note the tensioner move in conjunction with the noise. I'll take a look tonight and see what i see...


Thanks guys...

Nate

 

[fullahotair]

The alternator seems to spin freely, as does the pully. The AC pully, that doesn't spin as freely as the others do. Can anyone tell me how freely the AC clutch should spin?? If i spin it, it doesn't spin much farther then when i take my hand off the pulley.

I am putting a new turbo on, so once that is on, I can check a few more things out once it is running again.

Thanks,
Nate

 

["Turbo-T"]

Was it like this?:

YouTube - Alternator

If so it's probably a bearing. Mine would intermittently clunk, especially in the last few seconds of the video. You could feel the clunking thru the case.

A new alternator solved it. The old one even spun freely and had good voltage too.

 

[83ttypecooled]

Hi,
Alternators are reasonably trouble free;as a professional mechanic,I can tell you that I can't remember the last time I saw a bad bearing in one.They spin at probably a 4:1 ratio with the crank,but those roller bearings are like the energizer bunny;they keep going and going...
A more likely cause of your noise would be the AC compressor pulley bearing. While you have the accessory belt off,spin it again, and listen closely to it. ANY noise is not normal. Also, ANY play in the bearing is unacceptable. If the air still works,you can fairly easily replace the clutch.A removal/installation tool is required.A delete pulley is probably available,if you don't care about the air anymore.
I hope this helps,good luck with your issues.

 

[fullahotair]

The knock sounds much like that altenator in your video, but only those last couple seconds when it sounds like it rattles. It is intermittent, so at times it sounds/idles fine, and then rattles. It could be the AC pump however, that doesn't spin very freely and sounds rough... I do hear some noise in the alternator too, but not sure if it would be enough to say it was bearings. I'll guess i'll have to do some more trouble shooting, once i finish my turbo install. Thanks guys for suggestions...

Nate

 

[ChavoLC2]

Knockin' Alt.

I was drivin in from work when I turned into driveway all of a sudden she started knocking loud didn't know what the source of knock was from so immeadiately turned her off thought it was motor for sure... Parked her in the garage opened the hood and started her up knock,knock, you could see the alt. pulley wobblin'...alt was toast...Picked up a new stock replacement from Poston's not a rebuild so no core charge...........