Go Back   986 Forum - for Porsche Boxster & Cayman Owners > Porsche Boxster & Cayman Forums > Boxster General Discussions

Reply
 
LinkBack Thread Tools Display Modes
Old 09-25-2006, 12:33 PM   #1
Registered User
 
Join Date: Sep 2004
Location: Atlanta
Posts: 1,820
Weird Rumble from the Rear.....

Well, this is odd. From the right rear of my car, i get a distinct, deep rumble (both sound and vibration) when i corner hard in either direction. It happens at a lower threshold when i turn left. At first, i thought my tire was rubbing on something when the suspension compressed, but i looked for evidence of tire contact and cannot find any.

It seems to me that the only things that could potentially cause this are a bad wheel bearing or cv joint. I've never had a wheel bearing go bad and NOT make noise while driving straight, so i'm not sure if this is the culprit; there's no issue when driving straight or cornering leisurely. The sound / vibration is VERY similar to that of a front wheel drive car in mid turn with a bad CV joint. I visually inspected the boot; it's in good shape. It seems strange to me that there would be enough deflection in the rear suspension to move the CV joint past its 'normal' working angle.

Does anyone have any similar experiences or ideas? Also, i have found INNER CV joint kits for the Boxster. Is there an outer kit available? Thanks for the help.

__________________
insite
'99 Boxster
3.4L Conversion

http://i156.photobucket.com/albums/t...1/KMTGPR-1.jpg
insite is offline   Reply With Quote
Old 09-25-2006, 08:07 PM   #2
Registered User
 
Join Date: Jun 2006
Location: Minnesota
Posts: 33
I have lots of weird rumbles coming from my rear too......
joshuaalbert is offline   Reply With Quote
Old 09-26-2006, 03:15 AM   #3
Registered User
 
Join Date: Sep 2004
Location: Atlanta
Posts: 1,820
change your o-ring
__________________
insite
'99 Boxster
3.4L Conversion

http://i156.photobucket.com/albums/t...1/KMTGPR-1.jpg
insite is offline   Reply With Quote
Old 09-26-2006, 05:48 AM   #4
Registered User
 
Join Date: Jun 2006
Location: Minnesota
Posts: 33
I would if I could!!!
joshuaalbert is offline   Reply With Quote
Old 06-18-2015, 12:49 PM   #5
2000 Boxster S
 
camille's Avatar
 
Join Date: Aug 2014
Location: Urbana, Illinois
Posts: 13
I notice the same symptom. A steady vibration, around 10 or 20 Hz, only when cornering hard, in either direction. But the sound comes from all around, not just from one corner. I'm puzzled.
camille is offline   Reply With Quote
Old 06-18-2015, 01:00 PM   #6
98 Arctic silver 986
 
tommy583's Avatar
 
Join Date: Jul 2011
Location: Upstate, NY
Posts: 1,277
Garage
It could be your center motor mount. My car was making strange noises almost like a CV joint going bad around corners. Changed the mount and the sound went away.
tommy583 is offline   Reply With Quote
Old 06-18-2015, 02:00 PM   #7
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,400
Garage
Insite I think you have it narrowed down to the 2 most likely sources. If you have wheel bearings you've never changed I bet they need it. With your 3.4 I'd keep a close watch (ear?) on the CV joints too!
__________________
Jerk that is constantly criticzing new forum members and overly advertising my rebuilt engine for sale for a highly inflating price along with other miscellaneous parts accumulated over my 20 years of ownership.
BYprodriver is offline   Reply With Quote
Old 06-18-2015, 02:05 PM   #8
Beginner
 
Jamesp's Avatar
 
Join Date: Mar 2013
Location: Houston
Posts: 1,659
Garage
For brief moment I thought this was a treatise on Mexican food. Guess I've been in Texas too long.
__________________
2003 S manual
Jamesp is offline   Reply With Quote
Old 06-18-2015, 02:17 PM   #9
Custom User Title Here
 
particlewave's Avatar
 
Join Date: Mar 2012
Location: WA
Posts: 6,084
Garage
Quote:
Originally Posted by BYprodriver View Post
Insite I think you have it narrowed down to the 2 most likely sources. If you have wheel bearings you've never changed I bet they need it. With your 3.4 I'd keep a close watch (ear?) on the CV joints too!
You're responding to a 9 year old post, lol
particlewave is offline   Reply With Quote
Old 06-18-2015, 02:23 PM   #10
Registered User
 
ルーカス's Avatar
 
Join Date: May 2014
Location: Ottawa, ON
Posts: 121
Holy crap guys !
ルーカス is offline   Reply With Quote
Old 06-19-2015, 08:04 AM   #11
2000 Boxster S
 
camille's Avatar
 
Join Date: Aug 2014
Location: Urbana, Illinois
Posts: 13
Hmm. Say, tommy583, might an aging center motor mount also explain thunking and shuddering when accelerating briskly from a stop sign in second gear (tiptronic's default)? There's no shudder when accelerating in 1st, or gently in 2nd. (This car has about 100k miles on it. I've had it for a year. Sixth owner.)
camille is offline   Reply With Quote
Old 06-19-2015, 08:58 AM   #12
98 Arctic silver 986
 
tommy583's Avatar
 
Join Date: Jul 2011
Location: Upstate, NY
Posts: 1,277
Garage
Quote:
Originally Posted by camille View Post
Hmm. Say, tommy583, might an aging center motor mount also explain thunking and shuddering when accelerating briskly from a stop sign in second gear (tiptronic's default)? There's no shudder when accelerating in 1st, or gently in 2nd. (This car has about 100k miles on it. I've had it for a year. Sixth owner.)
Yes that is another common symptom of a failing motor mount. When I say center I mean the front, not the side (transmission) mounts. Although they could be getting to the end of there life as well. I would definitely say your front mount needs changing. There are plenty of DIY guides on how to do it. If you took it to a shop I would figure on a couple hours labor at most.
tommy583 is offline   Reply With Quote
Old 06-19-2015, 02:04 PM   #13
Registered User
 
BYprodriver's Avatar
 
Join Date: Oct 2008
Location: O.C. CA
Posts: 3,400
Garage
Quote:
Originally Posted by particlewave View Post
You're responding to a 9 year old post, lol
Oh, I was so glad to see insite posting! I wondered why he didn't already know this. This was before IMSB days!
__________________
Jerk that is constantly criticzing new forum members and overly advertising my rebuilt engine for sale for a highly inflating price along with other miscellaneous parts accumulated over my 20 years of ownership.
BYprodriver is offline   Reply With Quote
Old 06-24-2015, 02:03 PM   #14
2000 Boxster S
 
camille's Avatar
 
Join Date: Aug 2014
Location: Urbana, Illinois
Posts: 13
Made an appointment with a mechanic. I'll follow up here in a month with his diagnosis of the rumbling and shuddering.
camille is offline   Reply With Quote
Old 07-27-2015, 08:24 AM   #15
2000 Boxster S
 
camille's Avatar
 
Join Date: Aug 2014
Location: Urbana, Illinois
Posts: 13
Yup, as tommy583 guessed, engine and transmission mounts. The couple hours of labor isn't the big deal, but it's almost $1500 in parts, so I'll have to save up for that.
camille is offline   Reply With Quote
Old 07-27-2015, 08:32 AM   #16
Registered User
 
epapp's Avatar
 
Join Date: Aug 2013
Location: Bay Area
Posts: 700
Garage
I too have a similar rumble, 10 to 20hz when cornering hard and accelerating. I had assumed it was the front wheel bearing but this is making me think twice. My front engine mount is indeed in a horrible state (all of the symptoms of a bad front mount). I ordered a new one and will install most likely this coming weekend. ~$140, hopefully my vibration problem will be solved.
epapp is offline   Reply With Quote
Old 07-27-2015, 06:21 PM   #17
98 Arctic silver 986
 
tommy583's Avatar
 
Join Date: Jul 2011
Location: Upstate, NY
Posts: 1,277
Garage
Quote:
Originally Posted by camille View Post
Yup, as tommy583 guessed, engine and transmission mounts. The couple hours of labor isn't the big deal, but it's almost $1500 in parts, so I'll have to save up for that.
That seems really high for the parts, I would get another quote.
tommy583 is offline   Reply With Quote
Old 07-27-2015, 06:47 PM   #18
Registered User
 
EJ-Fresno's Avatar
 
Join Date: Oct 2014
Location: Clovis, CA
Posts: 517
Garage
Quote:
Originally Posted by camille View Post
Yup, as tommy583 guessed, engine and transmission mounts. The couple hours of labor isn't the big deal, but it's almost $1500 in parts, so I'll have to save up for that.
You meant $500, right?
__________________
2003 2.7 Boxster - Tiptronic - Carrera wheels - OBC - Red calipers - Cat pipes - Modified muffler - Rear speakers - K&N - Litronics
2006 V6 Mustang
2008 ML 350
EJ-Fresno is offline   Reply With Quote
Old 07-28-2015, 06:07 AM   #19
2000 Boxster S
 
camille's Avatar
 
Join Date: Aug 2014
Location: Urbana, Illinois
Posts: 13
$1500 wasn't a typo. I'm in the middle of nowhere (90 miles to the nearest dealer, only one guy in town who does Porsches).

Epapp: 1. If the rumble is absent when *coasting* and cornering hard, that shows the problem to be drivetrain, not wheels or suspension. 2. $140 is nicer than $1500, even if it's only the center mount, at least it's an improvement. You ordered WVO-986SSEM from Pelican Parts? Should I also buy their $40 wrench?

(Pelican also stocks the transmission mounts, left and right, for $370ish each 986-375-093-04-OEM and 986-375-094-04-OEM, or $115 "Rein OEM." That's closer to EJ-Fresno's $500 estimate.)

Last edited by camille; 07-28-2015 at 06:22 AM.
camille is offline   Reply With Quote
Old 07-28-2015, 06:50 AM   #20
Registered User
 
Chuck W.'s Avatar
 
Join Date: Sep 2008
Location: Agoura Hills (LA) So.Cal.
Posts: 1,571
Quote:
Originally Posted by camille View Post
$1500 wasn't a typo.
According to Pelican; Replacement Boxster transmission mounts include the triangle-shaped bracket. At about $250 each, they're pretty expensive. While performing the installation of the Porsche 996 engine into the Boxster, I discovered that the engine mounts from the 993 are functionally equivalent, and are sold without the triangle bracket for about one-half the cost of the Boxster mounts. You will have to carefully remove your old triangle bracket off of your old mount and install it on the new one if you decide to go this route. The stock 993 transmission mount part number is 993-375-049-05.

I would do this... buy from Sunset Porsche (http://www.************************************************************************.com/) and have them ship the parts to you.

Motor Mount $138.62 987.375.023.05

993 Transmission Mounts - Two at $163.89 = $327.78 993-375-049-09

Total $466.40 plus shipping.

Sunset sells the Boxster transmission mount with the bracket for $295.02 each. If you bought two of those and the motor mount from Sunset your at $728.66 plus shipping.

__________________
1995 Porsche C4 Cab

2016 BMW M2, 6 Speed LBB - ED 7/2016
1997 993 Cab - Sold; 1997 993 Turbo - Sold
2001 Boxster S - Original Owner - 30K Miles -SOLD

Last edited by Chuck W.; 07-28-2015 at 06:56 AM.
Chuck W. 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 05:47 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, 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