07-21-2018, 02:45 PM
|
#1
|
Registered User
Join Date: Sep 2012
Location: Greenville, SC
Posts: 43
|
Need help with dual mass flywheel...
So I had a new clutch & flywheel installed (sachs). The flywheel makes a loud whining sound every time I shift & let out the clutch. Also, makes a lot of nosie when decelerating. Also has a vibration around 3,000 RPM.
Mechanic seems to think its normal. Its been 10 years since I've owned a 986, but I don't remember it making all this noise.
|
|
|
07-21-2018, 03:52 PM
|
#2
|
So Blessed!
Join Date: Nov 2016
Location: SE Georgia
Posts: 389
|
Quote:
Originally Posted by Jim 'n' SC
So I had a new clutch & flywheel installed (sachs). The flywheel makes a loud whining sound every time I shift & let out the clutch. Also, makes a lot of nosie when decelerating. Also has a vibration around 3,000 RPM.
Mechanic seems to think its normal. Its been 10 years since I've owned a 986, but I don't remember it making all this noise.
|
Who installed the clutch and DMS? That's not normal to hear the noise you described. Could it be some of the springs on the DMS have come off or broken. There should be no vibration. When you shut down the engine with the clutch out, do you hear any noise, such as a rattle. If you do hear a noise try shutting down the engine with the clutch depressed. Report back!
__________________
Artic Silver Boxster S - Black Leather - Black Top - Convience Plus Package
|
|
|
07-21-2018, 04:21 PM
|
#3
|
Registered User
Join Date: May 2016
Location: Northern Indiana
Posts: 410
|
For perspective, it would be good to know the background of the mechanic to help understand the "it's normal" response. If it's "some guy with tools" it begins to make sense, if it's a Porsche master mechanic, then I'm really confused.
For the record (and without additional info), I'm in the "not normal" camp, but if the individual falls in to the latter of the two groups, I withhold the right to amend my opinion. Lol.
|
|
|
07-21-2018, 04:47 PM
|
#4
|
Registered User
Join Date: Sep 2012
Location: Greenville, SC
Posts: 43
|
This is a well respected INDY shop that specializes in German cars and has been in business over 30 years.
|
|
|
07-21-2018, 05:25 PM
|
#5
|
Custom User Title Here
Join Date: Mar 2012
Location: Ft. Leonard Wood
Posts: 6,163
|
You're sure it's a dual mass flywheel and not a lightweight flywheel?
Definitely not normal at all for a good dual mass flywheel.
|
|
|
07-21-2018, 10:18 PM
|
#6
|
Registered User
Join Date: Feb 2017
Location: CO
Posts: 989
|
The vibration could be your motor mount too. Very common, and perhaps your old dead clutch was masking it. Depending on year, if your motor mount is original stock, I’m 100% sure it would be dead and need replacing.
|
|
|
07-22-2018, 04:07 AM
|
#7
|
Registered User
Join Date: Sep 2012
Location: Greenville, SC
Posts: 43
|
It's definitely a dual mass fly wheel. They were suppose to check the motor mounts as well.
__________________
2003 Boxster 986 2.7 (Bought back my old car!)
2013 Boxster 981 2.7 Sold
2007 Carrera 997 3.6 Sold
2003 Boxster 986 2.7 Sold
1999 Boxster 986 2.5 Sold
|
|
|
07-22-2018, 04:16 AM
|
#8
|
So Blessed!
Join Date: Nov 2016
Location: SE Georgia
Posts: 389
|
Quote:
Originally Posted by Geof3
The vibration could be your motor mount too. Very common, and perhaps your old dead clutch was masking it. Depending on year, if your motor mount is original stock, I’m 100% sure it would be dead and need replacing.
|
Jim in SC says: The flywheel makes a loud whining sound every time I shift & let out the clutch. Also, makes a lot of noise when decelerating. Also has a vibration around 3,000 RPM.
It's my understanding all this started after the work was done. There was no mention of any vibration prior.
__________________
Artic Silver Boxster S - Black Leather - Black Top - Convience Plus Package
|
|
|
07-22-2018, 05:37 AM
|
#9
|
Registered User
Join Date: Sep 2012
Location: Greenville, SC
Posts: 43
|
Quote:
Originally Posted by Lew
Jim in SC says: The flywheel makes a loud whining sound every time I shift & let out the clutch. Also, makes a lot of noise when decelerating. Also has a vibration around 3,000 RPM.
It's my understanding all this started after the work was done. There was no mention of any vibration prior.
|
There was a vibration/whining prior to the clutch install. It is better now but still there.
__________________
2003 Boxster 986 2.7 (Bought back my old car!)
2013 Boxster 981 2.7 Sold
2007 Carrera 997 3.6 Sold
2003 Boxster 986 2.7 Sold
1999 Boxster 986 2.5 Sold
|
|
|
07-22-2018, 07:01 AM
|
#10
|
Registered User
Join Date: Jan 2014
Location: New Jersey
Posts: 1,631
|
Jake Raby says to avoid driving at a steady 3,000 rpm as that is the worst rpm for engine vibrations in these engines. Having said that, I find that 3,000 rpm in 6th gear is about where my car runs on highways to go with the flow of traffic so I do it all the time. Maybe your old dual mass flywheel was out of spec enough to mask issues that are starting in your motor mount and possibly also your transmission mounts. Or maybe some nuts and bolts weren’t fully torqued on reassembly? Even experts have occasional oversights on basic stuff, and putting it on a lift and taking a look is something I think they would do after you just paid for that big job.
I am not an expert in these matters by any means but these things may be worth checking out.
|
|
|
07-22-2018, 08:00 AM
|
#11
|
Certified Boxster Addict
Join Date: Nov 2010
Location: Los Angeles
Posts: 7,669
|
Not normal.
The shop should drive it and fully re-inspect. It should be fairly obvious if the engine or trans mounts need replacement. If nothing turns up from the inspection, then its time to remove the transmission again
__________________
1999 996 C2 - sold - bought back - sold for more
1997 Spec Boxster BSR #254
1979 911 SC
POC Licensed DE/TT Instructor
|
|
|
07-22-2018, 08:38 AM
|
#12
|
Registered User
Join Date: Oct 2014
Location: California Central Coast
Posts: 1,476
|
Might be worth checking the condition of the freewheel mechanism on your alternator.
|
|
|
07-22-2018, 04:02 PM
|
#13
|
Registered User
Join Date: May 2013
Location: North Alabama
Posts: 2,079
|
Cruise RPM
So what is the best RPM to cruise at ??
|
|
|
07-22-2018, 05:49 PM
|
#14
|
Registered User
Join Date: Jan 2014
Location: New Jersey
Posts: 1,631
|
Quote:
Originally Posted by Pdwight
So what is the best RPM to cruise at ??
|
My memory is going with old age. I was incorrectly recalling this Rennlist post I had seen a long time ago. Sorry about that!
|
|
|
07-22-2018, 09:20 PM
|
#15
|
Registered User
Join Date: Feb 2017
Location: CO
Posts: 989
|
Quote:
Originally Posted by Pdwight
So what is the best RPM to cruise at ??
|
6000...
I usually try to keep mine at about 32-3500ish. Never be afraid to rev a Porsche motor.
|
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is On
|
|
|
All times are GMT -8. The time now is 09:32 PM.
| |