I have 2008 CS4 with the X51 factory option. My serpentine belt broke on Saturday and decided to replace it myself. After taking the air box out I noticed that a couple of pulleys did not look like the pictures in the diagram so I had it towed to a local indy shop. They just got the whole pulley kit and replaced all of them. Has anybody else here had problems with broken/damaged pulleys?

I'm getting a bit anxious about something like a pulley going defective @ 65K (bought car with 62K 5 months ago).

Are 997's equipped with X51more prone to certain types of mechanical failures?

 

I do not think the serpentine belt and pulleys are any different in a X51. However, X51 engines are more complex with extra vanes in the airbox and elsewhere, and naturally higher complexity has a greater failure potential.

 

That makes sense. It's just that damaged pulleys is not something I've seen reported here.

Thanks!

 

Pulleys go bad and are often replaced.

 

Mine need to be replaced, but I'm at 110k. Doing my research online has brought up other isolated incidents. Seems like the pulleys get grooved and need replacing, which happened to mine.

Will be doing it soon. Best price I found was sun coast.

 

The belt is supposed to be changed at 60K if I'm not mistaken. Most replace the pulleys while in there to avoid failure.

 

To add to this there is a time requirement on the belt which I think is initially to replace after 6 years and then every 4 years thereafter if mileage does not require the change.

 

You sure "pulleys" were replaced?

I suspect idler/tensioner rollers were replaced. These can and do wear out. (My 2003 Turbo has had these replaced twice now in its 145K miles. However, my 2002 Boxster is on its original idler roller/tensioners now with 301K miles.)

Pulleys don't or shouldn't wear out. (As usual there are exceptions: My 2002 VW Golf TDi lost its V-belt due to an alternator pulley wearing out to the point it failed and the belt jumped off.)

But with these Porsche engines the belt is not supposed to contact the sides of the pulleys. In fact if it does this is a sign can be a sign an accessory drive is going bad -- is bad -- as it has developed enough bearing play the belt is no longer tracking true.