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

Reply
 
LinkBack Thread Tools Display Modes
Old 07-27-2011, 03:08 PM   #1
Registered User
 
Join Date: Aug 2008
Location: Arizona
Posts: 402
Clutch shudder at takeoff

I've changed my rear brake pads recently, after which I went on a 3 day vacation while my Boxster sat in the garage. When I came back, I noticed that after cold starts, the car would shudder (sometimes violently) as I engaged the clutch. This would continue only at takeoff for about 5-10 minutes until the car warms up, after which the shudder goes away.

I'm wondering if this has to do with the clutch itself, the brake pads, or perhaps the fact that over my 3 day vacation the monsoon season started in Arizona and the dew point and humidity shot up dramatically. I heard that due to the humidity there can be small buildup of water around the clutch, making it uneven. Can this be a cause?

Lordblood is offline   Reply With Quote
Old 07-27-2011, 03:23 PM   #2
Registered User
 
landrovered's Avatar
 
Join Date: Nov 2009
Location: Madison, Georgia
Posts: 1,012
Garage
Clutch judder is normally caused by grease or oil getting on the clutch disk, water can cause it as well but that happens when a car is immersed or wades a stream or deep puddle. I have never heard of humidity causing it.

The reason it goes away is because the grease, oil or water is burned off by the friction of the clutch engaging.

It would be very odd for it to have anything to do with your rear brake pads.
__________________
2001 Boxster S 3.6L, Zeintop
"Calling upon my years of experience, I froze at the controls." - Stirling Moss
landrovered is offline   Reply With Quote
Old 07-27-2011, 07:05 PM   #3
Registered User
 
Join Date: Apr 2009
Location: Australia
Posts: 328
I too have this problem. Was wondering what the cause was... Will see if the problem still exists once we start to warm up a bit (if it is dew on the clutch).

Sam
__________________
Australian Carbon Fiber nut
sparker is offline   Reply With Quote
Old 07-27-2011, 07:37 PM   #4
Registered User
 
The Radium King's Avatar
 
Join Date: Apr 2010
Location: Canada
Posts: 2,944
or it's you ims failing, spewing oil onto your clutch ...
The Radium King is offline   Reply With Quote
Old 07-28-2011, 05:57 AM   #5
Registered User
 
Join Date: Nov 2006
Location: In the garage...
Posts: 1,574
^


Anyhow, could be a number of things... more likely one of the following as opposed to overly-hyped IMS* issues:

- When was the last time clutch was bled? Should be done at a min every 2yrs w/ brakes but most dealers will skip unless you specifically request.

- Possible Master Cylinder issues?

- Possible bad motor mount?

- Possible clutch going bad. Any slippage in other gears?

- Possible bad clutch work? No offense meant but Porsche clutches have more travel and different pick up points than most other manual cars out there. To that point, from driving various Porsche models, the Boxster clutch is even different than other P-cars IMNSHO.

So, I'd start w/ something cheap like bleeding the brakes and clutch.

Good luck


* Yes, I agree some IMS issues exist and Porsche should stand behind within reason. However, from my experience and subscribing to numerous active forums, it's not nearly to the chicken little "sky is falling" extent some who profit from selling allegedly 'better' aftermkt replacements would lead you to believe.
Burg Boxster is offline   Reply With Quote
Old 07-28-2011, 07:11 AM   #6
Registered User
 
jcb986's Avatar
 
Join Date: Apr 2009
Location: Orlando
Posts: 1,266
In my experience with clutches and this goes back to my hot rod days. When revving the engine and letting out the clutch you get a point of slippage this then can cause hot spots on the pressure plate and the flywheel and usually will fade away after the engine "clutch assembly" warms up. Basically hot rodding and usually us guys like to get it on. Also, the other forum members have some good point of views. If it's an oil leak from the IMS or rear seal, you should have an oil leak so check under the engine. As I understand it, the clutch usually needs to be replaced once it has about 70K miles on it. City driving can wear on it faster.

Yeah, that is why I got one with a TIP.
__________________
http://i768.photobucket.com/albums/x...6/PC120055.jpg

Old Hippie Young Heart
2000 S/3.2 Liter/Tiptronic/Boxster S Sport Package/Cruise Control/Slate Grey Metallic
Red Special Leather Interior/Red Floor Mats/Red Hand Painted Instrument Dials/Roll Bar/Windstop
Small Carbon Package/Leather Wrap Carbon Wheel/Center Console Exterior Color/Alum Carbon Shift Knob
AM/FM Radio w/CD Player & Changer/Digital Sound Package/18" Turbo Wheels/Wheel Caps w/Colored Crest
jcb986 is offline   Reply With Quote
Old 07-28-2011, 05:17 PM   #7
Registered User
 
Join Date: Aug 2008
Location: Arizona
Posts: 402
If the IMS is starting to go, what would be the best route to take? I don't suspect it being the IMS because from what I know it's not THAT common compared to other problems. As I bought this car 6 months ago I have no idea when the brakes have been bled, and will start there. The car has 51k miles on it right now and the biting point on the clutch still is halfway up, there is no slip in any gears that I can feel (though I don't engage 6th gear...ever :P). I will have it checked out.

What is the average lifetime of a motor mount? I suspect this may be a problem as well. Are there other symptoms I should be aware of?
Lordblood is offline   Reply With Quote
Old 07-28-2011, 05:43 PM   #8
Porsche "Purist"
 
Paul's Avatar
 
Join Date: Aug 2003
Location: Wisconsin
Posts: 2,064
Garage
The IMS leaks onto the ground since it is behind the flywheel and very low on the motor.
__________________
1998 Boxster with 7.8 DME, 2005 3.6 liter/325 hp, Variocam Plus, 996 Instrument panel
2001 Boxster bought new. Installed used motor at 89k.
1987 924S. 2002 996TT. PST2
Owned and repaired Porsches since 1974. Have driven them all the way the Dr intended...
Paul is offline   Reply With Quote
Old 07-28-2011, 05:45 PM   #9
Registered User
 
Join Date: May 2011
Location: Miami florida
Posts: 1,591
I have the same problem. Its just a bit of chatter when launching at low rpm, 1200 of less. If I go above 2k rpm, the launch is smooth as silk. I changed the motor mount and it really didn't make a difference. Read somewhere its the dual mass flywheel.

My buddy, who has a 996, drove it said he didn't feel a thing, but he flogged the hell out of it. I try to launch as smoothly as possible, the clutch has 117k miles out of it so I want to milk it as long as I can.
__________________
Current car

2000 Boxster 2.7l red/black

Previous cars

1973 Opel Manta
1969(?) Fiat 850 Convertible
1979 Lancia Beta Coupe
1981 Alfa Romeo GTV 6
1985 Alfa Romeo Graduate
1985 Porsche 944
1989 Porsche 944
1981 Triumph TR7
1989 (?) Alfa Romeo Milano
1993 Saab 9000
san rensho is offline   Reply With Quote
Old 07-28-2011, 10:30 PM   #10
Registered User
 
Join Date: Aug 2008
Location: Arizona
Posts: 402
Quote:
Originally Posted by Paul
The IMS leaks onto the ground since it is behind the flywheel and very low on the motor.
If that's the case, the chance that it's an IMS leak is very low. I check underneath the car in the garage all the time every couple of days. So far it's been bone dry. I'm suspecting a small seepage or a worn out clutch/flywheel altogether.
Lordblood is offline   Reply With Quote
Old 07-29-2011, 12:39 PM   #11
Registered User
 
jcb986's Avatar
 
Join Date: Apr 2009
Location: Orlando
Posts: 1,266
The person before you setup how the clutch has worn because they were the drivers. What I would do, is find nice little stretch of private payment and re-seat the disk. Do you like your buddy did...rev up and get it on...no you will not have to burn rubber, but that might be fun to smokem' a little.
__________________
http://i768.photobucket.com/albums/x...6/PC120055.jpg

Old Hippie Young Heart
2000 S/3.2 Liter/Tiptronic/Boxster S Sport Package/Cruise Control/Slate Grey Metallic
Red Special Leather Interior/Red Floor Mats/Red Hand Painted Instrument Dials/Roll Bar/Windstop
Small Carbon Package/Leather Wrap Carbon Wheel/Center Console Exterior Color/Alum Carbon Shift Knob
AM/FM Radio w/CD Player & Changer/Digital Sound Package/18" Turbo Wheels/Wheel Caps w/Colored Crest
jcb986 is offline   Reply With Quote
Old 07-29-2011, 02:59 PM   #12
Registered User
 
ppbon's Avatar
 
Join Date: Nov 2005
Location: Florida
Posts: 529
My guess is that you have...

... a RMS leak, not an IMS Bearing leak.
The Rear Main Seal seals the main engine shaft where the flywheel and clutch are mounted.
Check under your car and see if you have oil collecting in the center of the engine.
If you have a bad enough RMS to cause clutch shudder you need to repair it soon or you will also have to replace the flywheel since petroleum products damage the dual mass elastometer in the flywheel.
Happy Boxstering,
Pedro

__________________
Racecar spelled backwards is: Racecar!
ppbon 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 04:20 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