Notices
996 Forum 1999-2005
Sponsored by:

Slipping

Thread Tools
 
Search this Thread
 
Old 05-03-2010, 11:56 PM
  #1  
conanr
7th Gear
Thread Starter
 
conanr's Avatar
 
Join Date: Jun 2009
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default Slipping

Over the past 3 months with 1500 miles, I have a random slipping problem (slipping - meaning it is in gear with little or no power and revs jump while attempting to accelerate). The first time this happened I thought either I was not in gear or it popped out - but that was not the case. This is with my 2004 911 turbo - 30k miles. I have driven this car around 40 times and have had 5 instances of slipping over the past 3 months. The strange thing is that I have noticed it in 2nd/3rd/4th gears. When I punch it while in 6th gear going slow - no slipping. Also, I have seen bar as high as 1.6 without slipping (in 3rd/4th gears). Out of the 5 times, 2 slipped quite bad (causing a burning smell - like the old electric race track cars when you let the wheels spin). During these 2 times, I noticed that the slipping began in 2nd and kept slipping into 3rd gear as well.

I have had bad clutches in the past, but none that behaved like this - so I need some feedback. I have talked to a couple of porsche mechanics and all say clutch. I would expect more consistency in the slipping if it were a clutch problem.

The strange thing is that when it does happen, if I pause and let the clutch engage - the slipping does not happen. It only happens when shifting gears quickly.

Any ideas - I would appreciate the feedback.
Old 05-04-2010, 12:06 AM
  #2  
ivangene
Parts Specialist
Rennlist Member
 
ivangene's Avatar
 
Join Date: Aug 2008
Posts: 16,326
Likes: 0
Received 24 Likes on 17 Posts
Default

Did the mechanic drive the car?


Its the clutch, have him demonstrate it to you.
Old 05-04-2010, 12:15 AM
  #3  
conanr
7th Gear
Thread Starter
 
conanr's Avatar
 
Join Date: Jun 2009
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

That is part of the problem. When I take it to a mechanic, it does not happen.
Old 05-04-2010, 12:53 AM
  #4  
Graufuchs
Rennlist Member
 
Graufuchs's Avatar
 
Join Date: Oct 2001
Location: LI NY
Posts: 3,328
Received 1,274 Likes on 472 Posts
Default

Possible leaky RMS dripping on clutch?
Old 05-04-2010, 01:30 AM
  #5  
conanr
7th Gear
Thread Starter
 
conanr's Avatar
 
Join Date: Jun 2009
Posts: 7
Likes: 0
Received 0 Likes on 0 Posts
Default

What would be the signs of a leaky RMS - would you see any fluid on the garage floor? The garage is clean - no fluid. What else could I see to determine if it was a leaky RMS?

Thank you.
Old 05-04-2010, 02:16 AM
  #6  
Graufuchs
Rennlist Member
 
Graufuchs's Avatar
 
Join Date: Oct 2001
Location: LI NY
Posts: 3,328
Received 1,274 Likes on 472 Posts
Default

RMS leak youd most likely see it on the floor unless its a minor one and is contained within, which is doubtfull. Just another possibility.
Old 05-04-2010, 02:37 AM
  #7  
Pac996
Drifting
 
Pac996's Avatar
 
Join Date: Dec 2009
Location: Aiea, HI
Posts: 2,919
Likes: 0
Received 3 Likes on 3 Posts
Default

Match the sought gears rpm more. You can fry a clutch down shifting too especially like you clutch is now. Beware that clutch can one time be just slipping once in a while then leave you sitting there going no where the next time you turn around. Get a clutch job is my advise.
Old 05-04-2010, 08:37 AM
  #8  
Barn996
Race Director
 
Barn996's Avatar
 
Join Date: Sep 2007
Location: Kittery, Maine
Posts: 11,801
Received 14 Likes on 12 Posts
Default

I'll be different here...clutch.
Old 05-04-2010, 09:35 AM
  #9  
Shark Attack
Rennlist Member
 
Shark Attack's Avatar
 
Join Date: Oct 2005
Location: Southern Utah
Posts: 11,012
Received 65 Likes on 34 Posts
Default

Originally Posted by fty
Possible leaky RMS dripping on clutch?
I think you have a valid possiblity here. When I pulled my clutch and I had a slight RMS leak my PP was a mess from the oil burning on to it.
Old 05-04-2010, 10:42 AM
  #10  
Sneaky Pete
Rennlist Member
 
Sneaky Pete's Avatar
 
Join Date: Nov 2008
Location: Mooresville, IN (Life Long Cheesehead)
Posts: 5,815
Likes: 0
Received 55 Likes on 36 Posts
Default

Originally Posted by Shark Attack
my PP was a mess .......


I say it is the clutch.
Old 05-04-2010, 10:49 AM
  #11  
Shark Attack
Rennlist Member
 
Shark Attack's Avatar
 
Join Date: Oct 2005
Location: Southern Utah
Posts: 11,012
Received 65 Likes on 34 Posts
Default

Originally Posted by Sneaky Pete


I say it is the clutch.
LOL... I just realized what you were getting at there..... HA HA ...

Actually it was my flywheel not PP that was a mess.
Old 05-04-2010, 11:02 AM
  #12  
ivangene
Parts Specialist
Rennlist Member
 
ivangene's Avatar
 
Join Date: Aug 2008
Posts: 16,326
Likes: 0
Received 24 Likes on 17 Posts
Default

I've heard enough about your PP

if it keep bothering you, you might try whacking it a bit
Old 05-04-2010, 11:15 AM
  #13  
nick49
Drifting
 
nick49's Avatar
 
Join Date: Apr 2006
Location: Out West
Posts: 2,006
Received 24 Likes on 16 Posts
Default

It sounds like you have an intermittent pressure plate problem. The friction disc may be fine at this point but the pressure plate is not holding 100% all the time. You describe it like the PP may hang sometimes and by giving it time to fully "press" engagement is positive. The only thing besides a clutch issue may be a viscious coupling issue in the diff either LSD or F-R drive. I'm not familiar with working on these systems on P cars so it's just a guess. I did have some momentary slipping on a Corvette that went away with a diff oil and additive change.
Old 05-04-2010, 11:25 AM
  #14  
ivangene
Parts Specialist
Rennlist Member
 
ivangene's Avatar
 
Join Date: Aug 2008
Posts: 16,326
Likes: 0
Received 24 Likes on 17 Posts
Default

or the disc is fractured and sometimes lays flat and sometimes doesnt - the important thing to note is that we all agree its the clutch "set" just get it replaced


any chance air in the hydrolic system would cause this
Old 05-04-2010, 11:32 AM
  #15  
nick49
Drifting
 
nick49's Avatar
 
Join Date: Apr 2006
Location: Out West
Posts: 2,006
Received 24 Likes on 16 Posts
Default

Air in the hydraulics may cause the clutch not to fully disengage and a spongy feel. It would have nothing to do with slipping, as the pressure plate applys engagement pressure and the disc. As the disc becomes thinner from wear it will reach a thin point where the pressure generated is not enough to hold and slipping will occur. Max pressure is with a disc of full thickness.


Quick Reply: Slipping



All times are GMT -3. The time now is 08:49 AM.