2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Engine Vibration upper RPM

Thread Tools
 
Search this Thread
 
Old Jan 19, 2005 | 12:44 AM
  #1  
DC350's Avatar
Thread Starter
Rotor Head
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 1,966
Likes: 0
From: British Columbia
Engine Vibration upper RPM

Hey everyone!

My engine vibrates at around 5500 and then stops above that... I was told it might be a wrong flywheel? an s5 flywheel when i have an s4 engine.. Do they even match up? Or could it be a loose motor mount or something? Happens in nuetral so it couldn't be the driveshaft..Any thoughts? I came up with Broken motor mounts...
Reply
Old Jan 19, 2005 | 01:04 AM
  #2  
BlaCkPlaGUE's Avatar
I live in an igloo
Tenured Member 05 Years
 
Joined: Jul 2004
Posts: 2,546
Likes: 0
From: calgary alberta
Believe it or not, but I've been told a couple times that a bad fanclutch can cause vibration at high rpm.
Reply
Old Jan 19, 2005 | 10:39 AM
  #3  
rotarypower86's Avatar
Full Member
Tenured Member 05 Years
 
Joined: Aug 2003
Posts: 136
Likes: 0
From: FL
It could be your trans mount. I had this problem recently. If you get under your car, and look at the crossmember, you should be able to tell if it's bad by the bushing on the bottom of the trans.

Charles
Reply
Old Jan 21, 2005 | 12:59 AM
  #4  
DC350's Avatar
Thread Starter
Rotor Head
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 1,966
Likes: 0
From: British Columbia
Thanks Gent's I'll get under there and take a look....
Reply
Old Jan 27, 2005 | 03:27 PM
  #5  
88AE's Avatar
Your mom goes to college
Tenured Member 05 Years
 
Joined: Jan 2005
Posts: 11
Likes: 0
From: Nanaimo, BC, Canada
Updates!!!!!!!
Reply
Old Jan 27, 2005 | 10:55 PM
  #6  
eriksseven's Avatar
Make Money.
iTrader: (6)
 
Joined: Oct 2003
Posts: 4,137
Likes: 9
From: Seattle
I had similar shaking. turned out to be a broken motor mount.
Reply
Old Jan 27, 2005 | 11:06 PM
  #7  
88AE's Avatar
Your mom goes to college
Tenured Member 05 Years
 
Joined: Jan 2005
Posts: 11
Likes: 0
From: Nanaimo, BC, Canada
Originally Posted by eriksseven
I had similar shaking. turned out to be a broken motor mount.
thats what he was tellin me it might be.
Reply
Old Jan 27, 2005 | 11:20 PM
  #8  
DC350's Avatar
Thread Starter
Rotor Head
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 1,966
Likes: 0
From: British Columbia
I was told a mis matched flywheel? Is that posible? Or a mis matched front counter weight....
Reply
Old Jan 27, 2005 | 11:40 PM
  #9  
Adam's Avatar
Rotary Enthusiast
Tenured Member 05 Years
 
Joined: Apr 2004
Posts: 908
Likes: 0
From: King of the road
Originally Posted by BlaCkPlaGUE
Believe it or not, but I've been told a couple times that a bad fanclutch can cause vibration at high rpm.

very true.. happend to me once. the fan turns slower than the moter because of the clutch and the vibration was a pulsing vibration, come and go within seconds, turned out to be the fan clutch
Reply
Old Jan 28, 2005 | 12:03 AM
  #10  
BDC's Avatar
BDC
BDC Motorsports
Tenured Member 10 Years
 
Joined: Jun 2002
Posts: 3,667
Likes: 6
From: Grand Prairie, TX
Originally Posted by DC350
I was told a mis matched flywheel? Is that posible? Or a mis matched front counter weight....
YES YES YES YES.

The rotors, front counterweight, and flywheel ARE A MATCHED SET. If you are using series 4 rotors w/ a series 5 flywheel, it will be off-balance. Change that flywheel pronto as you are rapidly killing the main bearings!!!!

B
Reply
Old Jan 29, 2005 | 10:26 PM
  #11  
DC350's Avatar
Thread Starter
Rotor Head
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 1,966
Likes: 0
From: British Columbia
Thanks B... I am going to rip it all out pretty soon... see what i've got goin on in there.... Nah, its not a worry.. I Have race bearings (I know thats no excuse) But The engine has Very low KM on it too.. And has not been driven that hard yet...

evan
Reply
Old Jan 29, 2005 | 11:49 PM
  #12  
NZConvertible's Avatar
I'm a boost creep...
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 15,608
Likes: 8
From: Auckland, New Zealand
If it rotates, it can vibrate. Engine, gearbox, driveshaft, diff, axles, wheels...
Reply
Old Jan 30, 2005 | 01:12 PM
  #13  
DC350's Avatar
Thread Starter
Rotor Head
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 1,966
Likes: 0
From: British Columbia
Damnit, that just makes the search worse! haha.... I dont think it would be the axles, wheels, diff, or gearbox, because it does it in neutral too....So somethin to do with the engine, or possibly mounts.
Reply
Old Jan 30, 2005 | 01:39 PM
  #14  
turbine's Avatar
Rotary Enthusiast
Tenured Member 05 Years
iTrader: (1)
 
Joined: Sep 2004
Posts: 906
Likes: 0
From: seattle wa
could be a miss at 5500
Reply
Old Jan 30, 2005 | 04:14 PM
  #15  
NZConvertible's Avatar
I'm a boost creep...
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 15,608
Likes: 8
From: Auckland, New Zealand
Originally Posted by DC350
I dont think it would be the axles, wheels, diff, or gearbox, because it does it in neutral too...
Unless the clutch is disengaged, parts of the geaqrbox are spinning when in neutral.
Reply
Old Jan 30, 2005 | 05:29 PM
  #16  
DC350's Avatar
Thread Starter
Rotor Head
Tenured Member 05 Years
 
Joined: Jan 2002
Posts: 1,966
Likes: 0
From: British Columbia
I'll check it out.

Thanks.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
trickster
2nd Generation Specific (1986-1992)
25
Jul 1, 2023 04:40 PM
Kyo
2nd Generation Specific (1986-1992)
6
Apr 13, 2019 09:24 AM
C. Ludwig
Single Turbo RX-7's
49
Jan 30, 2019 06:31 AM
CaptainKRM
2nd Generation Specific (1986-1992)
14
Aug 26, 2015 09:52 PM




All times are GMT -5. The time now is 06:20 PM.