iv got an 04 sedan, 6sp manual and i have this unusual vibration that i cant seem to find.

around 110-120km/h (68-74mph) and higher, which is exact highway cruising speed which makes it a pain in the ***, i get a vibration that will shudder the whole car for 1-2 seconds then goes away for 1-2 seconds then comes back for 1-2 seconds then goes away for 1-2 seconds and so on.

some days i wont notice it at all, some days very minor, some days its quite bad (like an unbalanced tire).

iv have 3 different sets of tires (all new) on the car, 3 different tire balance and wheel alignments from 3 different places, and iv had brake rotors replaced.

the vibrations seems to be a road speed as i can change gears between 5th and 6th while the vibration is noticeable and the frequency doesn't change.

anyone else had similar issue and been able to sort it?

 

im thinking uni joint in the drive shaft maybe, i had a look at it (the big rubber one) and it didn't look worn, didn't flex around overly much when i pushed and pulled on the shaft. not that i know how much it should actually flex around. ?

 

If you had the tires balanced correctly, then it sounds like a worn suspension bushing or shock absorber.

 

Only happens when driving? Not stopped

 

unsure how i could do 100+km/h while stopped

 

well if your still vibrating at stop then it's the driveshaft. Since it's always on the go then something else. So you can eliminate the driveshaft.

 

what? that make no sense.

i cant see how a vibration that happens at 100+km/h is going to happen when stopped. if im/the car is stopped, then so is the drive shaft.

 

Driveshaft still spinning when your stop. The only time its not spinning is when the car is off

 

no its not. the clutch disengages the engine/crank from the drive shaft. if the wheels arnt moving the drive shaft is not moving.

 

It disengages the gear but the driveshaft to the differential is still spinning. Jack your car up and start it. You will see it spinning

 

No, the drive shaft doesn't spin when the car is stopped lol, it only spins when the clutch is engaged to turn the pinion gear in the diff. wtf are you talking about. It will only spin if you leave the car in gear.

 

WTF?!

if it disengages the gear then it has disengaged the gearbox which means it has disengaged the drive shaft. when the clutch is in there is no connection from the engine to the drive line, therefore there is no way the drive shaft would be spinning if the car was stopped

if the drive shaft is spinning then the diff is spinning, if the diff is spinning the axles are spinning if the axles are spinning the wheels are spinning. this all happens when the clutch is engaged, and the car is moving

 

Lots of fail and win in this thread.

 

What was the original question? Lol.

OP, have you taken a look at your hubs? Had the same issue when one of my rear hub bearings needed changing. Also, if you have aftermarket wheels, are you using hub rings?

 

Check engine and transmission mounts to see if the rubber bushings have collapsed or worn.

While its jacked up be careful of the rotating driveshaft, LOL