Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Performance and Technical chat

Reply
 
LinkBack Thread Tools Display Modes
Old 08-14-2017, 08:24 AM   #1
Registered User
 
Join Date: Apr 2017
Location: Dyersburg TN
Posts: 20
Strange sound from engine

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
blvsmith is offline   Reply With Quote
Old 08-14-2017, 08:38 AM   #2
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,011
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?
Gelbster is offline   Reply With Quote
Old 08-14-2017, 08:41 AM   #3
Registered User
 
Join Date: Apr 2017
Location: Dyersburg TN
Posts: 20
Ok thanks for the advice. I am going to take belt off should I expect to be able to diagnose by turning pully.
blvsmith is offline   Reply With Quote
Old 08-14-2017, 09:34 AM   #4
Registered User
 
Join Date: Apr 2017
Location: Dyersburg TN
Posts: 20
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.
blvsmith is offline   Reply With Quote
Old 08-14-2017, 10:12 AM   #5
Registered User
 
kk2002s's Avatar
 
Join Date: Sep 2012
Location: S. New Jersey
Posts: 1,205
Garage
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
__________________
2002 S - old school third pedal
Seal Grey
kk2002s is offline   Reply With Quote
Old 08-14-2017, 10:37 AM   #6
Registered User
 
Join Date: Apr 2017
Location: Dyersburg TN
Posts: 20
Ok started engine belt off sound gone. That's a relief!. Going by to buy one of those diagnostic stethoscope. Thanks you so much.
blvsmith is offline   Reply With Quote
Old 08-14-2017, 11:46 AM   #7
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,011
Quote:
Originally Posted by blvsmith View Post
Ok started engine belt off sound gone. That's a relief!. Going by to buy one of those diagnostic stethoscope. Thanks you so much.
Don't remove the belt to diagnose worn pulley bearings.Stethoscope
Pullies -They are cheap/generic - do them all ?
Check the w/p bearing for weepage , run-out/noise. If in doubt replace w/p ?
The tensioner can be a problem - the bolt head on the back of it just spins sometimes.
Carry the old belt as a spare
Be aware some premium(Gates)new belts are stiffer than the OEM Conti.That may make them difficult to install
Gelbster is offline   Reply With Quote
Old 08-14-2017, 12:58 PM   #8
Registered User
 
Join Date: Apr 2017
Location: Dyersburg TN
Posts: 20
With belt back on and stethoscope in hand I check all and found the noise coming from alternator or upper idler pully. I really can not distinguish which one the noise is originating from. With the belt off the upper idler pully seemed fine. Could it be the alternator?
blvsmith is offline   Reply With Quote
Old 08-15-2017, 05:18 AM   #9
Registered User
 
kk2002s's Avatar
 
Join Date: Sep 2012
Location: S. New Jersey
Posts: 1,205
Garage
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
kk2002s is offline   Reply With Quote
Old 08-15-2017, 07:57 AM   #10
Registered User
 
Join Date: May 2014
Location: S.California
Posts: 2,011
Quote:
Originally Posted by blvsmith View Post
With belt back on and stethoscope in hand I check all and found the noise coming from alternator or upper idler pully. I really can not distinguish which one the noise is originating from. With the belt off the upper idler pully seemed fine. Could it be the alternator?
If your Stethoscope test is valid - yes the alternator bearings may be noisy/worn.
The freewheeling clutch on the Bosch alternator requires a peculiar little tool to remove it.But they are cheap on Fleabay.It is often very tight. Lots on Youtube to help you remove.
https://www.youtube.com/watch?v=p52VTAnLptI
There is an upgrade alternator on Amazon -inexpensive.
Replacing it -read the excellent Pelican DIY. There is one bolt that can be a pain ! Search.
Now is the time.
While you have the Alternator out inspect the cavity under the Inlt Manifold to see if vacuum hoses have been dislodged.
If you lack the tools/experience, you might want to find an M96 Indie for this......but we mentioned that earlier

Last edited by Gelbster; 08-15-2017 at 09:23 PM.
Gelbster is offline   Reply With Quote
Old 08-15-2017, 10:01 AM   #11
Registered User
 
Join Date: Apr 2017
Location: Dyersburg TN
Posts: 20
Ok great I am going to dive into the alternator if pully bearing doesn't do the trick. Thank you for all the advice and help. I have my dream car and now I am actually working on it. 986 for life!
blvsmith is offline   Reply With Quote
Old 11-01-2017, 04:02 PM   #12
Registered User
 
Join Date: Apr 2017
Location: Dyersburg TN
Posts: 20
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!

blvsmith is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -8. The time now is 05:00 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page