Poll: alternator life span - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Maxodus · 01-03-2011, 04:28 PM

Mine just gave up while i was driving locally and while waiting for the tow truck, i was wondering how long does this part usually last. The range of data may be huge but i thought interesting to look at.

So post up!

Frank M · 01-03-2011, 07:14 PM

It depends on what failed in the alternator.
Brushes usually last 200,000 miles +.
Pulley can fail anytme as well as diode bridge or regulator.
Bearings last along time as well.

Many alternators only need a brushes, regulator or pully for repair.

Maxodus · 01-04-2011, 09:47 AM

Good points Frank - i'm gonna take out mine and scrutinize which particular component failed me. Putting my Sherlock Holmes hat on.

Maxodus · 01-18-2011, 04:55 PM

some progress - opened up the engine bay and bearings and wiring and brushes on the alternator "looked" ok. So the other components may be at fault here (thinking regulator).

Gotta get my hands dirty and dig into the bay and pull out the alternator! Tight spot i've heard...

Mike_Yi · 01-20-2011, 08:44 AM

Before you think about removing your alternator, spray the sleeve at the rear of the inboard bolt with PB Blaster a day ahead of time. Then do it again shortly (an hour or so) before you try to remove your alternator. I broke my alternator trying to get it out. While JB Weld fixed it, it was a PITA.

Also, be VERY careful if you remove your regulator. On two alternators with two screws each, I broke off 3 of the 4. They are tough to remove.

MSull788 · 01-20-2011, 09:56 AM

I think 90000+ is normal. 125000mi on your alt is when you should stop thinking about long trips.

Maxodus · 01-28-2011, 11:39 AM

Quote:

Originally Posted by Mike_Yi

Before you think about removing your alternator, spray the sleeve at the rear of the inboard bolt with PB Blaster a day ahead of time. Then do it again shortly (an hour or so) before you try to remove your alternator. I broke my alternator trying to get it out. While JB Weld fixed it, it was a PITA.

Also, be VERY careful if you remove your regulator. On two alternators with two screws each, I broke off 3 of the 4. They are tough to remove.

Thanks for the pointers regarding the regulator screws - i better watch out for them this weekend when i try to remove them!

Maxodus · 02-14-2011, 03:36 PM

thanks for the votes yeah it looks like mine died relatively early - not sure what could have caused it. I have all stock electronics too, not like i'm pumping a huge AMP at the back.

The Autozone alternator tester showed failure on all parts (VR, rectifier and the diode thing).

I'm an electronic dummy but what should i check for when i suspect something in the car is causing the alternator to work harder than usual?

Maxodus · 02-14-2011, 03:40 PM

And for the record - i did have a flat battery 2 years ago (the original battery) and i tried to trickle charge it back up a few times and drive the car before i got a new one (Duralast brand). I've heard, afterwards, that this may not be kind to the alternator.

I've been running the car with the Duralast battery since then with no problem starting the car up.