Strange sound from engine - 986 Forum - The Community for Porsche Boxster & Cayman Owners

blvsmith · 08-14-2017, 07:24 AM

A week ago I started hearing a grinding sound coming from my engine. It's a 2001 986 and has 63,000 miles on it. Can anyone help identify what it might be and point me in the right direction. Here is a link to a video. quality is poor but you can hear the noise.
https://youtu.be/9YvGlt_BMfo

Gelbster · 08-14-2017, 07:38 AM

You'll get lots of guesses.
If you want a diagnosis suggest you ask here for a recommendation of a competent, honest Indie in your area.
A typical WAG would be idler pulley bearings(simple and cheap). If so & you neglect it, it could destroy the engine when the bearing seizes and the Serp belt hops off the w/p pulley.
PCNA may have a suggestion for an Indie?

blvsmith · 08-14-2017, 07:41 AM

Ok thanks for the advice. I am going to take belt off should I expect to be able to diagnose by turning pully.

blvsmith · 08-14-2017, 08:34 AM

I got the belt off and the idle pulled seem to spin fine. Some videos I've listened to that sound like myou issue have all been cooling pump but the cooling pump was replace 13k miles ago. I know thats a week spot could it have gone out again. It was replaced before I owned the vehicle. I have put 5,000 miles on it.

kk2002s · 08-14-2017, 09:12 AM

With belt off start car, is the sound gone??? then it is pulley related
There are (3) idealer pulleys - spin feel for resistance.
The AC pulley has a clutch and the alternator also has a clutched pulley
If it's pulley related but you can't isolate then with belt back on and car running using one of those diagnostic stethoscope you should be able to isolate which pulley it is

blvsmith · 08-14-2017, 09:37 AM

Ok started engine belt off sound gone. That's a relief!. Going by to buy one of those diagnostic stethoscope. Thanks you so much.

kk2002s · 08-15-2017, 04:18 AM

As I mentioned I believe the alternator pulley has a clutch so that could be it alternator could be bad as well. Not sure you can just fix alt. pulley
Here you probably should remove belt and hand spin with stethoscope to further isolate between alternator or idealer pulley

blvsmith · 11-01-2017, 03:02 PM

Just to give update. I ended up replacing the alternator and problem solved. Even better it only cost me 50 bucks. I bought a junkyard alternator off ebay and it worked. Indi shop was going to charge me 800 bucks...no no no I say!