I'm getting a rattling sound out of the engine on my 2007 997 C4S w/45,000 miles. I can easily hear it at idle outside the car, don't know what happens under load. I have videos of the sound below.

To me, it sounds kind of like the noise that the tension pulley is making on my wife's 2004 3-series with 130,000 miles. I'm only at 45k, so it seems early for a pulley to be going.

In any case, I welcome any opinions on what this is. I'm pretty sure that it didn't make this nose in the past....

Looking around on youtube, there are a bunch of videos that sound somewhat similar, with hypotheses ranging from a bad lifter, bad pulley, bad flywheel.

Any thoughts?

I made videos of the noise here : and

 

could be a pulley. if i were you, i'd take off the belt and spin them by hand to see if any are loose, binding, rattling, etc.

 

It is hard to get the belt off? I installed AWE sport cats and a set of rotors on the car myself - so that's about my skill level at the moment.

 

nope not hard at all. here's how to remove the air box:

https://www.6speedonline.com/forums/997/245647-diy-air-filter-change-2005-997-a.html


and here's how to remove the belt:

http://forums.rennlist.com/rennforums/6387369-post22.html

 

spiffyjiff,

Thanks for the reply! After you de-tension the belt, how do you know how much tension to put on the belt? Do you just keep track of how many turns of the 24mm nut? Or is the tension not affected by removing the 24mm nut?

-Jim

 

the tensioner pulley is on a spring loaded arm. so basically you're applying torque to the bolt in the center of the pulley so that the arm bends down bit so that you can take belt off. when you let go of the wrench it will spring back in place (until you bend it down again to reinstall belt). make sense?

 

Fantastic! So you don't have to remove the 24mm bolt to de-tension the belt. You just torque on it to bend against the stpring. That explains why in the rennlist walk through it suggests that the bolt should be turned clockwise. I thought that was strong.

That makes it even easier.

Thanks!

 

yep, that's all there is to it. good luck and dont forget to post your success!

 

+1 to the above... it really does sound like a pulley bearing.