Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 7 Series / 8 Series > 7 Series - E38 (1995 - 2001)

7 Series - E38 (1995 - 2001)

Reply
 
Thread Tools Display Modes
  #1  
Old 03-15-2011, 02:41 PM
Danny Wolfe Danny Wolfe is offline
Registered User
Location: USA
 
Join Date: Feb 2011
Posts: 88
Mein Auto: 2001 740i
Driveline vibration~flywheel???

Hello AGAIN...the project continues. This time i am trying to diagnose a vibration. I have a vibration when i have the car in neutral or park. This occurs when i rev the engine and at about 1500 rpm i feel the vibration. I have replaced the fan clutch and fan. I also feel the vibration while driving at about 40 mph and is most noticeable at with the car in the highest gear. This vibration seems to go and come in and out when going up a hill or when the car is in more of a strain. I was advised that this could be the flywheel and damper. Can anyone enlighten me on the flywheel set up, and if you think this possibly the problem. I have not replaced flex disc either. What are these cars known for? Is the drive shaft usually something that fails at this mileage...., or flywheel? This car has 166k miles.
Thanks again for your continued advice and help....as ALWAYS!
Reply With Quote
Ads by Google
  #2  
Old 03-15-2011, 07:35 PM
joyism5's Avatar
joyism5 joyism5 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Jan 2011
Posts: 1,270
Mein Auto: '99 740IL, K75RT
I doubt that is your flywheel. They do not fail. Maybe once in a while but only if you have a clutch on them. So far I have not seen a failed flywheel. Audi maybe , BMW not.

Shaft it can't be either if you have the problem in Parking too.

Vibration damper I have not seen to fail either to BMW. Could be misaligned but if you did not remove it it's not your case.

I would suspect engine mounts and transmission mount.

Check engine is ON when this happens?
Reply With Quote
  #3  
Old 03-15-2011, 09:38 PM
CodyItaliano's Avatar
CodyItaliano CodyItaliano is offline
Officially Welcomed to the 'Fest
Location: Corpus Christi, TX
 
Join Date: Feb 2009
Posts: 628
Mein Auto: 2001 740i
if your car is automatic, you have a flex plate. those occasionally crack, have never see this as a problem with BMWs. this part is attached to the engine, and the torque converter to it.

the torque converter can sometimes cause noticeable vibration if it is going out. what is the mileage of your car? if its high and the fluid hasnt been changed, theres a good chance that could be it.

otherwise if the car runs and isnt making weird noises from the transmission, its probably fine.

it could be your motor mounts or transmission mount, especially saying that it is above idle and not at high rpms. i would bet it is one or more of the mounts.
__________________

*Der E38*
manufactured: 7/01
color: anthrecite metallic
wheels: style 89 E66, 19X9F 19X10R
ext. lighting: 8000k D2S & LED plate light
*want to get sport rear diff*
Reply With Quote
  #4  
Old 03-15-2011, 10:06 PM
Danny Wolfe Danny Wolfe is offline
Registered User
Location: USA
 
Join Date: Feb 2011
Posts: 88
Mein Auto: 2001 740i
Thanks guys! I do not have a SES light when this is happening. I do not know how to check for he transmission mounts or engine mounts. I can feel it at idle in my feet as well, but only a small bit. However, it is definitely there at 1500....and does not go away. The flex plate that you were referring to is made in the flywheel isn't it....that is what i was told at BMW. I dont just want to start replacing parts and not knowing what the problem is. My car has 166k miles. I have not changed the fluid in the trans and the trans seems fine to me...very smooth and quiet. I do know that the flex disc has not been changed either....but that would not explain the vibration sitting still....OR COULD IT STILL ??? I think this could possibly be a couple of things going on here....BTW....when i had engine mounts go bad on my mercedes, it was most noticeable at idle. When i gave it more rpms, the vibration would decrease or go away. Thanks for your help...I am lost on this one too!
Joyism5: I have not confirmed yet, but i am pretty sure that battery light IS the alternator....cannot find a problem in the cables. I guess i will take the alternator off and go have it bench tested. Maybe that will tell me for sure!
Reply With Quote
  #5  
Old 03-16-2011, 06:27 AM
joyism5's Avatar
joyism5 joyism5 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Jan 2011
Posts: 1,270
Mein Auto: '99 740IL, K75RT
Quote:
Originally Posted by Danny Wolfe View Post
I do not know how to check for he transmission mounts or engine mounts.
You can have somebody in the car shifting couple times from P to R and P to D, Have it in D and let it go forward couple inches and apply brake firmly. All this time you need to be on the side of the vehicle, with the hood open watch the engine mounting supports on both sides for movement. If they move engine mounts are shot . This technique does not apply for tranny mounts. They are far away under the car. A visual inspection should be enough. If the rubber part has a big crack from one side to the other one...is gone.
They are fairly easy to change and not expensive I think . Have a read through this , comments too : http://www.bimmerboard.com/forums/posts/155477

About the alternator...I feel sorry for you that you need to remove it for for a check. I hope that it is under warranty. I got 3 or 5 years on mine.

Good Luck!
Attached Thumbnails
Click image for larger version

Name:	195.png
Views:	103
Size:	10.0 KB
ID:	270546   Click image for larger version

Name:	tranny mounts..png
Views:	94
Size:	6.1 KB
ID:	270547  
Reply With Quote
  #6  
Old 03-16-2011, 08:49 PM
Danny Wolfe Danny Wolfe is offline
Registered User
Location: USA
 
Join Date: Feb 2011
Posts: 88
Mein Auto: 2001 740i
THanks....now about the FLEX PLATE....is that part of the flywheel?? I also am trying to figure out where these tranny mounts are. On realoem, i see a rubber piece that is rectangular and a metal angle piece that goes with it. Can you tell me how many mounts the tranny has? I see two in the upper picture. Is this a job that i can do at home? ....thanks!
Reply With Quote
  #7  
Old 03-16-2011, 10:12 PM
CodyItaliano's Avatar
CodyItaliano CodyItaliano is offline
Officially Welcomed to the 'Fest
Location: Corpus Christi, TX
 
Join Date: Feb 2009
Posts: 628
Mein Auto: 2001 740i
an automatic does not have a flywheel. a flywheel is only on transmission that are manual, and have a clutch.

a flexplate is what would be in the same place the flywheel would, except it is much thinner and has the torque converter bolted directly to it.

here's some pictures to help you visualize what i'm talking about. as you can see the flex plate can easily crack. highly unlikely for a BMW, but not uncommon as far as happening period. hope this helps you understand the part in question better.

FLEXPLATE



FLYWHEEL

__________________

*Der E38*
manufactured: 7/01
color: anthrecite metallic
wheels: style 89 E66, 19X9F 19X10R
ext. lighting: 8000k D2S & LED plate light
*want to get sport rear diff*
Reply With Quote
  #8  
Old 03-17-2011, 04:17 AM
joyism5's Avatar
joyism5 joyism5 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Jan 2011
Posts: 1,270
Mein Auto: '99 740IL, K75RT
Both manual and automatics have flywheels . For automatic transmissions the flywheel has a drive plate AKA flexplate where the transmission torque converter is mounted in those 4 holes, this is removable (in this case), and the manual trans does not have a drive plate because there is no torque converter there is a clutch with a pressure plate and flywheel is more thicker. Here is the picture from a 2001 740 with the flywheel # 1 and drive plate # 3.The other picture is from my past 99 M62 engine. Same as yours.

Like codyitaliano said is highly unlikley for BMW to have issues with that.

When I was saying above that it might not be the flywheel the problem, I was talking actually about your drive plate. I might got misunderstand .

Transmission mounts, you have 2 of them (If I remember right) located at the rear of tranny .

Good Luck!
Attached Thumbnails
Click image for larger version

Name:	DSC_0287.jpg
Views:	112
Size:	95.1 KB
ID:	270666   Click image for larger version

Name:	flywheel.png
Views:	95
Size:	6.3 KB
ID:	270668  

Last edited by joyism5; 03-17-2011 at 05:35 AM.
Reply With Quote
  #9  
Old 03-17-2011, 08:08 AM
balance balance is offline
Officially Welcomed to the 'Fest
Location: NC
 
Join Date: Feb 2009
Posts: 758
Mein Auto: 97 740iL
40mph is usually the speed at which a bad torque converter will shudder, and I think that the lock up clutch only engages on the last gear on these cars, so that's my guess.

To check for motor mounts, I usually just go inside the car, hold the brake firmly, and hit the gas to see if the motor has lots of side to side play when it is torqued. I don't think it is a mount issue since you usually feel a bad mount when the transmission shifts roughly.

If it happens on Park and Neutral, it is not the driveshaft.

In the original post he said the "flex disc" not the "flex plate". The flex disc is the part on the driveshaft that connects to the transmission, otherwise known as the giubo, and that is not the problem.
Reply With Quote
  #10  
Old 03-17-2011, 09:01 AM
joyism5's Avatar
joyism5 joyism5 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Jan 2011
Posts: 1,270
Mein Auto: '99 740IL, K75RT
@ balance : Very true and possible your theory ! Does this vibration will appear when car is parked and raising the rpm? Or a torque converter issue will appear only in driving conditions?



Quote:
Originally Posted by balance View Post
In the original post he said the "flex disc" not the "flex plate". The flex disc is the part on the driveshaft that connects to the transmission, otherwise known as the giubo, and that is not the problem.
Correct ! ! !

He mentioned above about the damper and flywheel that's why I was thinking about the flex plate.

Quote : I was advised that this could be the flywheel and damper .

Last edited by joyism5; 03-17-2011 at 09:07 AM.
Reply With Quote
  #11  
Old 03-17-2011, 10:39 AM
balance balance is offline
Officially Welcomed to the 'Fest
Location: NC
 
Join Date: Feb 2009
Posts: 758
Mein Auto: 97 740iL
That's the thing that bothers me joyism5, I have never heard of a bad torque converter causing vibration while the car was in Park or Neutral, but I don't know too much about transmissions and I'm not sure if this is possible or not, it was the other problems that he said he was having that made me think it was the torque converter.
Reply With Quote
  #12  
Old 03-17-2011, 10:55 AM
joyism5's Avatar
joyism5 joyism5 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Jan 2011
Posts: 1,270
Mein Auto: '99 740IL, K75RT
OK...I was on the same frequency....Never heard before about a flywheel issue , and never heard about vibration caused by flywheel/drive plate. If somebody experienced something like that ... please make light in the dark room.
Reply With Quote
  #13  
Old 03-17-2011, 10:38 PM
Danny Wolfe Danny Wolfe is offline
Registered User
Location: USA
 
Join Date: Feb 2011
Posts: 88
Mein Auto: 2001 740i
Thanks Gentlemen!!! I do feel that with 166k miles and having NEVER changed the transmission mounts, i will go ahead and replace them before i go into the FLex plate. I will get them installed first, then motor mounts.....THEN if i still have the vibration at 40 mph, i will go farther. Our weather was close to 80 degrees today and it seemed to me that the problem was not nearly as bad as usual. NOW TONIGHT, being somewhat cooler, the problem is as pronounced as ever. Sounds like a "rubber" thing to me maybe with the difference in the temp....What do you guys think? OH. BTW: The reason my mechanic told me that this was the flexplate???? He was turning the engine by hand when doing the timing repair with the valve covers and timing covers off, and he told me that he could hear it when he turned the engine. I DONT KNOW!!! I am leaning towards the rubber engine mounts, and the rubber tranny mounts. QUESTION: Where this flexplate bolts on to the crankshaft, is there some sort of a rubber mount that goes between the flexplate and crankshaft???? OR the torque converter?
Reply With Quote
  #14  
Old 03-18-2011, 06:36 AM
joyism5's Avatar
joyism5 joyism5 is offline
Officially Welcomed to the 'Fest
Location: USA
 
Join Date: Jan 2011
Posts: 1,270
Mein Auto: '99 740IL, K75RT
It is mounted on the flywheel and to the crankshaft. No rubber between. Picture above .
Reply With Quote
Reply

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 7 Series / 8 Series > 7 Series - E38 (1995 - 2001)
Today's Posts Search
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 Off



Forum Jump


All times are GMT -7. The time now is 02:41 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms