Hello all!

I have a question for the experienced members to this forum.

Problem
- Vibration throughout the speed range (from 40 and up) especially around 60km/h and 125km/h i get a bouncy feeling in the car, not the steering wheel.
- At certain speeds it seems to be worse, the feel is when you drive a rough road.
- Over the past year, it seems to get worse.

What have i done?
As i am busy with this problem over a year now, i have tried a lot of things:

- New MAF
- Changed hose between MAF and throttle body
- Injector cleaned and tested (professionally)
- New reconditioned cilinderhead (with other cams/valves/variator)
- When cilinderhead was off the cilinder walls and pistons were inspected and all engine bearings (pistons out)
- Compresion ok and the same on all 5 cilinders
- Changed variator solenoid
- New spark plugs (5 pieces)
- New coils (5 pieces)
- Changed throttle body
- Changed ECU
- New engine mounts (3)
- Wheels balanced (a lot of times)
- Alignment doen (a lot of times)
- Other set of rims with new tires
- Changed drive axle left & right
- Inspected the differential & diff. bearings
- New left wishbone
- New wheel bearings front (left & right)
- No fault codes in all the ECU`s
- New PCV (positive cranckcase ventilation)
- Changed engine rpm sensor
- Changed Selespeed ECU (solved the jerky pickup)
- Inspected the front and rear catalytic converters
- Checked lambda values (post cat 0.5V while stationary driving)

As you can see i spent some time and effort in trying to solve this 'little' problem. But until now without any result, vibration is still the same (yes also with other rims/tyres )

Noticed
I am kind of lost now, which direction i need to look. What i notice at the moment:

- Replaced both differential axle seals two times due to leakage now ok, strange?
- Gearbox whine especially through 1-2-3 (you can hear it inside the car)
- no major play where the axles go in te differential
- Selespeed changing gear rough

idea`s?
- At the moment i am suspecting it must be somewhere in the gearbox / flywheel area. But i replaced the flywheel / clutch in 2010 (5 years ago ) Although maybe because the old Selespeed ECU was very rough / jumpy on pickup it destroyed the dual mass flywheel?

I thought i tried to log the 'Clutch travel' when driving. If there is a imbalance on the flywheel it may have impact on the clutch travel? below is a graphic of the clutch travel during stationary driving (engine speed vs clutch travel)



I see that the clutch travel during steady driving (around 60km/h) fluctuates between 15.85mm and 15.10mm (0.7mm difference) is it possible that any of you can make a log so we can compare the values?

And ofcourse if anyone has an idea....

You haven't said how you're feeling the vibration. Through the steering? Through your seat? I could be at the rear (rear discs or hubs?).

Yellow Peril: Vibration is definitly from the front, i can see the hood bouncing up and down. Vibration is felt through the car. Steering wheel is silent and steering is smooth.
It 'll be most helpfull when someone can make a MultiECUscan log with the 'clutch pressure plate travel' and 'engine speed' at approx. 60 km/h. Then i can compare this to mine.

Took my my car out. Results seems similar with 0.6 variation.
Is vibration road speed or engine speed related?
Gearbox in manual, does changing gear change things?

Maigretnz, thanks for checking ! So i can assume that this behaviour is normal. When the vibration occures, it is mainly at cruising road speed. I tried shifting from 5th to 4th and 3rd gear but the vibration stays the same. This keeps the only option, gearbox or diff? Tires and rims already changed but this didnt help. Also both axles are replaced (used ones, but vibration stayed the same)
As this is the selespeed i cant shift in neutrale when the vibration occurs, so this complicates the search...

I was going to suggest neutral on a hill but then noticed you were in Netherlands lol.
Have you looked at the dampers? A suspension shop may have equipment to test while still on the car.

Lol, a good hill is difficult to find here indeed

I tried this morning again on my way to work, vibration at around 60 km/h. shift from 5 to 4 (keeping the foot on the pedal and maintaining the same speed), still the same vibration. Strange thing is that during the shift, the vibration seems to be gone? or less noticable. I know selespeed shifts in about 0.7secs so the de-clutch time is very short. but somehow you can notice the vibration is less during the gear shifting process.

Dampers (all 4) are replaced in 2010 for 'monroe' ones. Since then i put around 40k kilometers on them. Damping seems to be good, no bouncing and not rock-solid.

Have you tried putting the car on a rolling road at an auto tuning place?