Vibrating while releasing clutch

[p406]

Hi everyone.
So, the last year I bought a 406, 2.0HDI, 90hp (2001). I noticed a vibration exactly at the moment where the clutch engages in 1st and sometimes in 2nd gear, but always stronger in 1st. Everything else in that car was in perfect shape, so I thought myself that the reason for the vibration is the clutch, I would change it and everything would be OK. But that's where I was wrong.
I went to the mechanic, they also said it's most probably the clutch, so they replaced it, but... no luck. The vibration was still there, even though it was less. I went back to the service, they said they would investigate further on the problem... then they told me that probably the new clutch is defective or something like that. They replaced it again, and at the beginning everything was alright, but then after a short period of time, the vibration started again... I went to another service, where they told me that they didn't found even a single problem and everything is just fine. Тhey didnt take off the clutch or the transmission to check it though, they only looked at other parts like motor mounts, etc... In the next few days I'll be taking the car again for a complete check once again, but I would want to hear some opinions here as well. Thanks in advance.

[PeterN]

Sounds strange. What sort of a vibration is it? Is it clutch judder or a mechanical vibration, does it only happen as you are pulling away or will it also do it when stationary?

Peter

[p406]

Yeah, its a clutch judder and it only occurs when im pulling away...

[Doggy]

Hi & welcome aboard.

Could be your lower engine mounting - can you rock the top of the engine back & forwards by hand?

[p406]

Hi and thanks.
Well I haven't tried, but I will do, even though in both services I went to they told me they don't see any problem with any of the mounts.
Anyways I'll try that and post back, thanks.

[PeterN]

I would think its either got to be the clutch or an engine mounting, you haven't got oil leaking onto the clutch have you? The clutch plate can get roughed up causing that particularly if you only use very low revs when pulling away which on a diesel you normally would, try slipping the clutch on a hill for about 10-15 seconds and see if that improves it.

Peter

[p406]

The engine seems stable. I tried by pushing the car while in gear, that way the engine moves a little bit but thats normal I guess.. Btw I also have noticed that the front wheels shake together with that vibration.

[PeterN]

If the clutch is juddering it will have an effect on the wheels - and most other things. Try giving it a bit of a slip and see if that improves things

Peter

[p406]

I did - no improvement. I missed to mention that it vibrates the most at 1100-1500 RPM. At 1500-1800 it is much less, at about 2000 its completely gone. But well, starting every time at 2000 rpm is a bit too much for a diesel.. And it isnt really comfortable. I have heard of some cases like mine, where people begin moving away at higher rpms, and after some time the problem goes away. Idk if that would help in my situation though.

[p406]

Sorry for double posting, but a few minutes after my last post, things changed and after slipping the clutch a bit more, the vibration is now almost gone.

[PeterN]

I don't think its peculiar to DMFs I remember one or two of my older cars having the problem and it was cured by a bit of clutch slipping.

Peter

[p406]

Well, I continued slipping it sometimes while driving today. It is kinda better, but certainly it is not completely gone. Should I keep slipping from time to time or that would kill the clutch.

[PeterN]

As long as you can't smell it burning it should be OK but once it drives OK it should stay like that unless its got oil leaking onto it.

Peter

[Welly]

Could be oil leaking from the main crankshaft oil seal and getting onto the clutch itself? Whilst changing a clutch it's always worth changing the oil seal whilst your in that area and for what it costs, same as changing a water pump whilst doing the cambelt it's all about taking advantage of the labour time.

I wouldn't consider stripping it all back out to change an oil seal at this stage, if your engine mounts are good than Peter's suggestion of regular (sympathetic) clutch-slipping is a good shout.

[Welly]

Could be oil leaking from the main crankshaft oil seal and getting onto the clutch itself? Whilst changing a clutch it's always worth changing the oil seal whilst your in that area and for what it costs, same as changing a water pump whilst doing the cambelt it's all about taking advantage of the labour time.

I wouldn't consider stripping it all back out to change an oil seal at this stage, if your engine mounts are good than Peter's suggestion of regular (sympathetic) clutch-slipping is a good shout.