Help: Alternator needs replacing at 42,000 mi? Price jacked up in past year?

[socratic]

Because of some worn pulleys on the alternator/waterpump area needing replacement, I took it into the dealer.

The bad news is that they believe that the alternator is contributing to the noise and feel it needs to be replace. The initial estimate was maybe $400 for the alternator.

Now I'm told that the dealer has discovered that Porsche has jacked up the price by over 100%. Retail cost (before installation!) of the alternator is now over $1000.

First, is it possible that there is a worn out bearing inside the alternator itself or a worn or bent shaft that is causing the noise and could it have happened at only 42K?

Second, is there an alternative to a full retail price OEM Porsche alternator? If so, where and what? Can third-party alternators be trusted? An alternate source perhaps?

[spine911]

It is possible that the bearing inside the alternator would start failing and could start making noise...ALMOST ALL Alternators that are sold by a part shop or your local dealer are Rebuilt. Rebuilt Alternators also carry some warranty(approx. 6mo-1yr) depending on the dealer. The quality of Rebuilt Alternators are as good as your Brand New Alternator....I once purchased a Rebuilt Alternator from ****************************************.COM(Miami,Florida) for my 86 944 which i completely rebuilt about 4yrs ago(4yrs/85k miles since) and still performes like Brand New...Another alternative would be to find a local Starter/Alternator repair shop in your area and have it rebuilt.--will probably cost you below $100 to rebuild(same quality with warranty as well). Rebuilding/Reconditioning an Alternator is not Rocket Science and is extremely cheap/and easy to repair ...Im sure your local Porsche Dealer would take your core to be rebuilt by a local shop and resold for 10x the orig. repair cost....Having owned 3 previous Porsches before my Box, ived saved tons of $$$ just ordering quality Porsche parts from ****************************************. They are very knowledgeable with Porsches and has competitively priced high quality parts.

[Tool Pants]

http://www.boschusa.com/AutoParts/AlternatorsStarters/RemanAlternators/

[socratic]

Thanks for coming through so quickly with help guys.

I'll check those places out.

[Brucelee]

Rock Auto has alternators from $180-329. www.rockauto.com.

[deliriousga]

You may be able to have it rebuilt locally. I'm getting a local rebuild for about $100. They're replacing the bearings and brushes so it should be as good as new.

[socratic]

Thanks John.

I'm having a local rebuilding ship look at it. Their initial comments were that the rotor is worn out and that they feel that Bosch, makers of the alternator, have designed the alternator badly and that more and more Boxsters will have this problem.

I'm going to try to go down to their shop and take a look at it now that they have it apart.

An interesting read for an alternator rebuild is here (the page below is on page 4 of 6 and has a picture of what a rotor is):

http://www.alternatorparts.com/cs130_sbpage4.htm

[deliriousga]

I'm having a problem with mine too. Planning to rebuild because of the noise it's making. It sounds like the bearings are worn and the pulley/spindle vibrates making a rattle.

I wanted to re-build it myself, but I can't find a kit with the replacement parts and I don't want to pull it apart and have to wait a week for parts after I figure out what needs to be replaced. Maybe someone will come up with a kit if it becomes a common problem.

[socratic]

The rebuild shop is thinking of spray-welding to "build up" the worn area on the shaft if they can't get a replacement Bosch rotor.

Can anyone comment on spray-welding to beef up a worn shaft?

Just curious, how many miles are on your Boxster John?

[socratic]

Originally Posted by socratic

I'm having a local rebuilding ship look at it. Their initial comments were that the rotor is worn out and that they feel that Bosch, makers of the alternator, have designed the alternator badly and that more and more Boxsters will have this problem.

I'm going to try to go down to their shop and take a look at it now that they have it apart.
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An update. The rebuild guys were FAST. By the time I dropped by at like 11am, they had already fixed it and it was on the truck going back to the dealer.

So I didn't get to see it or take a "Before" picture. The guy described it as the bearing having worn a "valley" on the rotor shaft. The free play between the bearing and the shaft resulted in the vibrating noise.

After having no luck locating a rotor from Bosch, they went ahead and spray-welded the shaft--essentially depositing enough metal onto the shaft that it then exceed the diameter of the original shaft, thus filling in the "valley" plus a little more. Then they machined it down to the correct diameter.

The downside he said is that the spray-weld metal is softer than the original shaft metal. So maybe in a few years, I might need this done again.

The good news is instead of $1100 + taxes for an OEM alternator, I now have one that should be vibration free for $150 total including taxes.

And for the $150, they had gone to the dealer to pick it up, fixed it and returned it to the dealer in the span of less than business day(!)

The dealer will install the repaired unit in the next few days and I'll know if the noise is fixed and provide and update then.

[spine911]

Glad to hear you saved $$$ instead of the dealer $1100 alternator(which is more than likely a rebuilt as well)

[socratic]

Ok, so here's the outcome.

The dealer put the rebuilt alternator back. It's running fine, probably better than when I got it a few months ago. Note, originally there was a rattling sound that indicated a bad pulley. Similar to what was experience by the fellow who posted this topic:

Lost my idler pulley Fri.

So the combination of a bad pulley and a worn rotor in the alternator caused a variety of "bad engine noises": a low frequency rumble/rattle at low rpms and a sound that I had originally thought was a gearbox whine around 3000rpm.

All the noises are now gone and the engine sounds very smooth again.

I advise people to listen carefully to the sound their engine makes. If you hear an abnormal rattle or low frequency rumble then it might very well be a pulley(s) and/or the a worn rotor in the alternator. Get it serviced as soon as you can. I noticed in mine that once the wear in either the pulley or the alternator (or both) manifests itself, it gets worse quickly.

If it turns out that it's a worn rotor in the alternator, you may want to consider doing what I did, namely: have the alternator rebuilt by a specialty shop for about $150 USD instead of paying $1100 for an OEM Porsche alternator. Only time will tell how well the rebuild went, but the new pulleys and re-worked rotor in the alternator returned my Boxster engine to the sweet sounding beauty it was before.