Technical My Sei is "vibrating"...

[tnt]

So the problem is as follows:
- when the engine is cold (in the morning, about 0 to +4 C degrees outside), I push the clutch pedal to the floor, engage 1st gear, rpm at ~ 2300 and slowly releasing the clutch pedal. Somewhere at the middle of the clutch pedal course, when the car starts to move there is a vibration I can feel all over the car body (and the dash is vibrating).
- if I am releasing the clutch pedal faster, the car will move forward without vibrations (maybe the tyres will scream a little if the rpm is higher).
- when it comes to change to 2nd gear, it is a bit difficult to move the gear lever... I must force it a little.
- after the engine is hot (~ 5 km on the city traffic, waiting at traffic lights...) when engaging 1st gear and slowly releasing the clutch pedal, the vibration of the car body and dash is stronger then when the engine is cold. At this point, my passenger airbag starts to vibrate inside the dash compartment making a noise similar to a phone vibrating on a plastic table. This happens somewhere at the middle of the clutch pedal course.
Again, if I am releasing the clutch pedal very fast, the vibration is no longer present...
- now, with the engine hot, the 2nd gear is very easily to engage, smoothly without forcing the lever.

I don't know exactly what the problem is... the clutch, the gearbox or one engine support... all I know is that when the engine is cold the vibrations are less pronounced, and they are increased after making ~5 km on town traffic and the engine heats up...

 

[rallycinq]

Probably engine mount would be the first thing to check. The one under the habaticle is the most common for failing.

Cheers

SPD

 

[tnt]

The symptoms described are the ones for a failed engine mount?

 

[Diwiak]

try shift reverse and quickly release clutch if theres some weird sound

 

[tnt]

No, no strange sounds from the clutch or gearbox... nothing. No matter the gear... the only thing I am worried is where the vibration comes and why the 2nd gear is hard to engage when the engine is cold?

Another thing I noticed is that, when in town traffic, if I am traveling at 15 km/h and I am in 2nd gear, the rpm's are too low and I want to change to 1st gear it is very difficult to engage 1st gear while moving... I have to do one of the following:
- double press the clutch and between actions I must accelerate ~3000 rpm
- braking until almost stopping and then engage 1st gear
This is very annoying...

 

[rallycinq]

Adjust clutch and check gear box oil for quality and quantity.

Cheers

SPD

 

[Radlet6]

No, no strange sounds from the clutch or gearbox... nothing. No matter the gear... the only thing I am worried is where the vibration comes and why the 2nd gear is hard to engage when the engine is cold?

Another thing I noticed is that, when in town traffic, if I am traveling at 15 km/h and I am in 2nd gear, the rpm's are too low and I want to change to 1st gear it is very difficult to engage 1st gear while moving... I have to do one of the following:
- double press the clutch and between actions I must accelerate ~3000 rpm
- braking until almost stopping and then engage 1st gear
This is very annoying...

The juddering sounds like clutch judder - this is caused by either the linings on the clutch plate getting low, the release bearing sticking, or contamination of the clutch plate (possibly with oil)

What happens is as you lift the clutch slowly and it approaches the point where the plates come together, the clutch bites, then slips, then bites then slips, then bites....etc giving the sensation of juddering. Lifting the clutch faster obvioulsy brings the plates together faster thus giving less opportunity for the bite-slip process - hence less vibration.

The problem with first gear selection is probably related in that the clutch is not releasing properly.

 

[tnt]

For not leaving the thread without an end, I have to say that yesterday I had my clutch kit changed with a brand new one . I replaced the whole kit: pressure plate, clutch disc and release bearing. The new kit is from RUEN (we'll see hoe good it is by time).

Now the problem: The old clutch that was fitted to my car was not a standard 180mm . Somebody (before I bought the car) replaced the original kit with a Valeo 170 mm kit :bang:. The pressure plate had cracks ALL OVER the contact surface with the clutch disc. And, being an 170 mm kit, around the edge of the flywheel there was a portion (a circle) of 50 mm that wasn't used (there was rust there).
Also, the release fork (the one that presses the release bearing) had its two forks a little bit used and had some imperfections at the ends. This were fixed too with some welding.

Now the vibration is gone, everything is smooth when changing gears. After I will make a long trip with the car and some town-driving I will come back with a feedback.