Alternator has no label, what is it?

[iowaguy]

My alternator seems to be making a lot of noise and I need to replace it. I can't find Bosch or anything else on it, just a number: 21105117. That's it. Anyone know how I can tell what I need for my car? 1995 325ic. Last 7 of vin if that helps: JC82915.

[2slow4u]

Are you sure it's the alternator? Does the vehicle start like normal or do you have to jump start it? More than likely it's the tentioners

[JordanE36]

Might be the tensioners like 2slow4u said, but ive also experienced my alternator making a whining noise before it went out

[iowaguy]

If I put a long screwdriver on the alternator and listen the noise amplifies. When I run electronics (turn on headlights, lower all the windows) the engine seems to need to surge a bit and other things dim.

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I guess maybe what I'm wondering is should I get the 140 amp since I have the convertible or is 80 amp sufficient?

[pjo33us]

The make plate is under the plastic shroud in the back. Real OEM should show which one you are supposed to have. Does sound like one of the pulleys though.

[JordanE36]

If I put a long screwdriver on the alternator and listen the noise amplifies. When I run electronics (turn on headlights, lower all the windows) the engine seems to need to surge a bit and other things dim.

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I guess maybe what I'm wondering is should I get the 140 amp since I have the convertible or is 80 amp sufficient?

You can actually just upgrade to the 105a bosch. Unless youre planning on running a huge sound system, its not really needed. A buddy of mine actually bought a remanufactured 105a and only used it for about a month before he upgraded to the 140a because he was running a new system. I can probably get you a good deal on it if you want

[Eric93se]

If it has a green ring around the center of the alt, then its a valeo. But you can use a bosh one too, I think the pullies are different, so you might have to hang on to your old pulley before doing the core return. Rockauto has a good selection, the Beck/arnley brand seems to have a good rebuild.

[autoguy]

If it has a green ring around the center of the alt, then its a valeo. But you can use a bosh one too, I think the pullies are different, so you might have to hang on to your old pulley before doing the core return. Rockauto has a good selection, the Beck/arnley brand seems to have a good rebuild.

reguarding the first post:
My alternator (http://forums.bimmerforums.com/forum/##) seems to be making a lot of noise and I need to replace (http://forums.bimmerforums.com/forum/##) it. I can't find Bosch (http://forums.bimmerforums.com/forum/##) or anything else on it, just a number: 21105117. That's it. Anyone know how I can tell what I need for my car? 1995 325ic. Last 7 of vin (http://forums.bimmerforums.com/forum/##) if that helps: JC82915.

Response....
BMW tends to be a little tricky when matching up alternators to applications. No matter where you look you will find more than one option for your vehicle, both in amperage and mfg type.

Regardless of which alternator you do have you are able to install the following options:
If you are looking for a 140amp alternator I recommend you purchase the a Bosch alternator that will replace the 80amp or 140amp Bosch or Valeo alternator.
If you only need the 80amp alternator I recommend the 80amp bosch replacement alternator, regardless if you have the valeo.

If you not 100% sure your alternator is bad I recommend you drive the car to a reputable rebuilder in your local area that can test the alternator on the vehicle. If it does test good but you believe it is making noise the only way you can know for sure if that noise is coming from the alternator would be to remove it and have it bench tested.

Hope this info can help.... have a great day!

[low36]

Most come with an 80A alternator stock. There are upgrade options to a 140a as I have but it may be overkill depending on how much draw your system has.

Take a picture of your alternator and it will be easier to identify, but I almost guarantee its the 80A. Also, do you see a stamp in the plastic of the air inlet on the alternator?

[flyfishvt]

Having a vert has absolutely NO effect on the size of your alternator. The top only operates occasionally and even then it only operates for a few seconds. In fact you can even operate the top with the engine off. The 80 amp alt will be just fine unless you have a massive sound system. Super large subs are about the only thing that stress a 80amp alt.

If you have a BOSCH alt the name BOSCH will be on the black plastic on the back of the alt right below where the alt cooling duct attaches. Its probably covered with dirt. You can't miss it. BOSCH in super large letters