Intermittent clutch engagement issue

[darkcat]

I have a 2010 CDI, 75000 miles, It has started occasionally misbehaving as follows.

This is currently happening maybe 1-in-5 times I start:

- Start car (engine hot or cold, makes no obvious difference), hold brake and push gear lever left to put in gear as normal, A on dash as normal.
- Try to move away and it basically dumps the clutch (as in dropping the clutch way too fast in a manual) and the car jolts forwards, sometimes it will stall the engine die to this.
- Re-start the engine and it behaves as normal, on a few occasions I've had to restart a couple of times.

I've also had it do this to me ONCE so far when I came to a stop at a junction with the engine running. re-started and it was OK for the rest of the trip.

Other things to note:
- When stone COLD and behaving normally I get a small amount of clutch judder as it engages, sometimes.
- On some occasions when its changing from say 2nd to 3rd in auto, the engine revs a little higher than I would expect as it engages the clutch.

Could this simply be the actuator needing adjusting to deal with clutch wear? actuator greasing? (Both?) or a sensor issue?

[tolsen]

Clutch actuator in the 451 automatically adjusts itself at each stroke.

Most likely causes are 1) stiff actuator mechanism or 2) broken or partly broken wiring or both 1 and 2.

[darkcat]

Thank you - interesting - ok so first port-of-call is to remove, thoroughly clean and re-lube the actuator both internally and externally, re-install in original position (and check wiring while its off)

Are they prone to wire damage in a specific place?

[tolsen]

I am a 450 person so do not know exactly positions where wiring fails on a 451.

When cleaning out the internals of clutch actuator, beware that motor brush gear is at bottom of motor nearest to actuator sector mechanism. Therefore keep clutch actuator in horizontal position just as it is fitted when you clean and lube its guts.

Also, make sure no oil or grease contaminates rubber gaiter. Clean area where gaiter seals against housing and rod. Apply silicone grease to these areas to improve weather protection.

[OMA]

Happening to me on my recently acquired 451 CDi
Ive got the AA parts and garage cover so will get them to come and diagnose it then assuming the garage will most likely replace the actuator
£535 cover for £35 excess and £24 a month with my 2010 Discovery 4.

Dave