Vibration

[seafeye]

Does anyone know the proceedure for narowing down a vibration problem?

Vibration starts at around 70mph and really noticable around 84mph.

Put on new tires hoping that would help. (Didn't)

Replaced a rim because one was borderline round. That didn't change much either.

Have bought some wheel bearings but haven't changed them yet. If someone can post

a picture of the tool needed to remove the bearing without removing the hub that would

be great.

If i change the wheel bearings and still nothing then what next?

Second problem:

When i lift off the clutch to change gears i get a clunk. Same if i push the gas

pedal quickly off and on. Ideas? Comes from behind the seats. Ie: engine area

Motor Mount or Clutch?

Third:

Can someone post a link as to where i can buy the tool to remove a leaky oil tube?

Thx

[Chris_in_NH]

the vibration between 70 and 84 MPH is usually a wheel (or wheels) out-of-balance. since you changed your tires, i assume that they were balanced. it is possible however, that one of the wheels wasn't balanced properly, or maybe even lost a wheel weight.

you might find a shop with a Hunter balancing machine, take it there, and get your wheels balanced again. it will probably cost you $25 per wheel, but then you can rule out the wheels if the vibration is still present.

here's a site where you can locate a Hunter machine. http://www.gsp9700.com/

i have no idea about the other stuff. sorry...

[seafeye]

the vibration between 70 and 84 MPH is usually a wheel (or wheels) out-of-balance. since you changed your tires, i assume that they were balanced. it is possible however, that one of the wheels wasn't balanced properly, or maybe even lost a wheel weight.

you might find a shop with a Hunter balancing machine, take it there, and get your wheels balanced again. it will probably cost you $25 per wheel, but then you can rule out the wheels if the vibration is still present.

here's a site where you can locate a Hunter machine. http://www.gsp9700.com/

i have no idea about the other stuff. sorry...

Yes i will check the wheels again. When i bought a replacement wheel i went to a high performance shop that had the high speed balancer. They told me that the wheel and tire were well balanced. So that is why i am leaning towards the wheel bearing.

[markab986]

If a good road force machine tech can't find it...

Several things come to mind

tires (balance, tread/belt slippage), rims (out of round, bent, debris stuck inside), lug nuts

steering, suspension, bushings, alignment

drive train, axles, bearings, cv joints

loose body/trim panel (flapping in the breeze)

See if you can id the harmonics, speed, and general location

Sounds like a trip to a certified P-doc

Good luck

:cheers:

Edited May 11, 2007 by markab986

[spongebob]

The clunk that you hear is probably the front motor mount and that can also be a cause of the vibration at approx. 75 mph.

When the engine passes through the 3000 rpm range it's not uncommon to have some resonance vibrations ,especially not with a worn out motor mount.

Bbut of course check the tires first.

[jl1252]

Don't know about your tires, but I too, have the infamous vibration that occurrs between 3-3500 RPMs. My money is on the motor mount. I'll probably have mine replaced under my extended warranty.

No tool is needed to remove your spark plug tubes. I simply inserted my thumb and pressed it against the inner wall and pulled. Every one came right out wihtout the need of any special tool. There are two 'O' rings per tube and both had flat spots along their entire circumference which I suspected was the cause of my oil leaks. The manual also calls for a special tool for inserting new tubes, but again, none is really necessary. I was able to exert more than enough force to pop them back into place.

Good luck,

Jeff

[spongebob]

Don't know about your tires, but I too, have the infamous vibration that occurrs between 3-3500 RPMs. My money is on the motor mount. I'll probably have mine replaced under my extended warranty.

No tool is needed to remove your spark plug tubes. I simply inserted my thumb and pressed it against the inner wall and pulled. Every one came right out wihtout the need of any special tool. There are two 'O' rings per tube and both had flat spots along their entire circumference which I suspected was the cause of my oil leaks. The manual also calls for a special tool for inserting new tubes, but again, none is really necessary. I was able to exert more than enough force to pop them back into place.

Good luck,

Jeff

Had a Porsche mecanic to testdrive my car to day as I have done everything to get rid of this vibration around 3200 rpm and he just told me to sell the car or learn to live with it....

It's because of material mixture in the engine (steel and aluminum)I did not understand everything he said but it was something about the steel crankcase between aluminum cylinders that causes the vibration.

Although I still beleive I can fix this with a lightweight flywheel.

[seafeye]

Don't know about your tires, but I too, have the infamous vibration that occurrs between 3-3500 RPMs. My money is on the motor mount. I'll probably have mine replaced under my extended warranty.

No tool is needed to remove your spark plug tubes. I simply inserted my thumb and pressed it against the inner wall and pulled. Every one came right out wihtout the need of any special tool. There are two 'O' rings per tube and both had flat spots along their entire circumference which I suspected was the cause of my oil leaks. The manual also calls for a special tool for inserting new tubes, but again, none is really necessary. I was able to exert more than enough force to pop them back into place.

Good luck,

Jeff

Had a Porsche mecanic to testdrive my car to day as I have done everything to get rid of this vibration around 3200 rpm and he just told me to sell the car or learn to live with it....

It's because of material mixture in the engine (steel and aluminum)I did not understand everything he said but it was something about the steel crankcase between aluminum cylinders that causes the vibration.

Although I still beleive I can fix this with a lightweight flywheel.

So can you actually see if the motor mount is crap without taking it out of the car?

I have had all wheels balanced so i doubt that they are the problem. I do have the wheel bearings on a shelf at home, i guess i just have to get the courage and time to do the job. I guess while the car is on jacks i can see the mount....Stay tuned.

[Komplex]

Taking out the motor mount might be overkill. I had a similar problem this winter, I assumed (as you did) it was the rims or the tires.. So I put up with it for a month till spring rolled around and had my summer rims/tires put on and balanced.. So problem fixed right? Well, no... The same thing was happening, I was just about to bring it in to the dealer when my local mechanic suggested I get the wheels aligned.. So one alignment and $70 later I have no more issues :thumbup: