I keep my fingers crossed, BJ, that it won't be catastrophic!

Btw...while on a parking lot yesterday, i put in the 1st gear kinda sloppy...and it was kicked out again immediately...man, that sounded like a catastrophic engine failure :D

Isn't there supposed to be a belt around those pulleys ;)?

I don't think you should use that belt again.........
Have you any idea why it tracked off - the tensioner pulley usually keeps a good tight reign on the belt?

Good, it's not the IMS. So was it the alternator as suggested by other?

It was frayed. And had a tick for a while before finally giving, it likely would have broken if it wasn't for shutting off the engine so quick.

Check all your idler pulleys & tensioner while the belt is off, they may have caused the belt to track improperly & easy to replace now.

Sweet. That's great, Jake!

Always good to hear of one saved.

how often does an alternator seize ? I have never seen this happen before ....

On manual transmission cars, the alternator has a free wheel clutch integrated with the pulley. This can seize in a worst case scenario.
A couple of years ago, I heard a slight clicking / rattle sound @ idle which stopped when I ran the engine with the accessory belt removed. I found it was the alternator clutch on its way out - it felt very notchy when turned by hand.
You also need a special splined removal tool to get the clutch off the shaft.

Your welcome.


See 100+ M96 powered cars a year and you'll see it often. In the past year I have probably made this call 7-8 times and been right every time.

Guess how I diagnosed this with such little information... It wasn't luck!

Nice work Mr. Raby. I have no idea. Worked on more m96s than I have seen on the road in my life? Just guessing!!

Whew! I never thought a breakdown would be such good news. ;)

Awesome BigJake! Nice call Mr Raby!

It doesn't surprise me that Jake was able to do this long distance email diagnosis, he has probably seen and duplicated every failure mode on these engines ! Nice call Jake.

Just my opinion, anyone buying a used Boxster, unless they have documentation showing that the serpentine belt has been changed in the last 10-15K miles, should replace it. Inexpensive, easy to do, and a great way to avoid headaches down the road. I carry a spare belt and a 21mm/24mm open end wrench in the car (along with a few other tools), just in case.

Exactly why I have my little emergency bag along with extra belt, relays, etc just in case. It is great that it was a simple fix.

Learn something new everyday (Problem is remembering them) that these alternators have a clutch. Makes sense that these can seize if the clutch goes.
So now add Alternator clutch to the preventative maintenance list

Is there a Clutch kit for these?

I did a AC compressor clutch kit on my 03 Jeep liberty, about $90 and a couple hours. So Much cheaper than replacing the Compressor.

So the question here, Did a pulley seize or was it a worn belt that jumped the pulleys?

+1 on extras - long trips I carry my old Belt and the tools to change it

+1 Credit to Jake for making the right call early on.

Do some of these model alternators have a break away clutch at the pulley in case this happens?

a really unscrupulous mechanic could have had a field day.

Three things that are rare...
1. good pizza.
2. loyalty.
3. honest mechanics.

Good to know, I never realized the 986 has a clutch on the alternator. Every one is quick to blame the ims, now that I think of it even the video I found sounds like a serpentine belt flapping around. I wonder how many mechanics have taken advantage of this.

So either BIG Jake is really happy right now, or a little down as he already had eyes on his next Boxster!

Glad to hear it was an easy fix.

Not all of them do. The units with a spray clutch seize only in the clockwise direction, the engine can still be rotated counter clockwise when these fail.

I've had cars shipped to me from 2000 miles away that were supposedly failed, and this was all that was wrong with them. I told one guy to remove the belt and try to start the engine; but, he was so convinced that it was blown up that he just sent the car anyway.

I fixed it in 45 minutes and called to tell him that he could save his 20K. he was so blown away that he spent 10K on performance and preventatives while the car was with us.

This failure fools lots of people. I bought a core engine for 500 bucks once, and all that was wrong with it was a failed alternator.

IIRC the Tiptronic cars don't have the overrun pulley clutch device. When mine was failing, a new one cost about 50% of the alternator price - but that's here in Australia. The US guys should be able to get the part much cheaper, though you do need a special removal tool to get the thing on / off.
Bosch Overrun Pulley part#535002510
INA alternative part #535002510

http://986forum.com/forums/uploads01...1431110139.jpg

:D