Signs of impending DMF failure

[skomedal]

Passat estate comfort line 06 diesel, BKP motor, 132 miles, DSG auto gearbox. Bought S/H Nov 2014.

Had this into the local VW dealership ( 60 miles away ) for replacement headlight washer pump and replacement of rear suspension bushings, they noticed also right front wheel axle bearing was dodgy so gave permission to replace this also.

5 hours later and 1K lighter went through other potential probs with the service dept. they had noticed a slight noise from the DMF flywheel.

What can I do to confirm this, and what can I possibly do to postpone this costly replacement issue?

All replies welcome

[DMitch16]

Depends how slight the noise is? Very, very slight i.e. hardly noticeable and you'll get a few thousand miles out of it yet. On both DSG and manual a worn DMF usually makes a quiet metallic chatter in neutral. This gradually gets louder as the DMF starts to wear excessively. Badly worn DMFs sometimes need to be cut off as the securing bolts and holes in the centre go out of alignment meaning you can't undo the bolts to remove the DMF from the crank. Failures can be spectacular but usually by then the DMF is making a lot of noise and should have already been attended to (replaced). DMF for a DSG is a shade under £300 retail and usually an LUK. As it is a gearbox off job, it won't be cheap at a main dealer.

[skomedal]

Thanks for the reply.
As the dealership just mentioned it as an aside, and I cannot hear any noise will just try to follow the situation.

[DMitch16]

A new DMF is pretty stiff when it comes to rotational movement of the two halves with only a small tolerance built into the spring mechanism inside as is normal. The two halves are solidly attached to each other so there should be no movement other than rotational. Over time and much use the torque forces cause the bonding of the two halves to relax and there is a small amount of separation which causes the clatter as the two halves under vibration (more vibration at idle) clink against each other. The springs also relax causing excess rotational movement of the plates back and forth as they try to counter the crank torsional forces under load. As the separation gets worse the clinking becomes clanking (for want of a better way of explaining the sounds!) and you will definitely hear it long before the DMF is likely to give up or disintegrate. Most of the bad failures are as a result of ignoring the tell tale sounds or not realising what it is and not having it looked at before it is too late.

There are Youtube videos of cars running with badly worn DMF units for you to make sound comparisons should you need to.

[skomedal]

Update

Have just returned from a 60 mile trip whilst looking for signs of this fault, the automatic gearbox shifted all gears smoothly the motor pulled effortlessly in all gears, popped the bonnet and noticed just a slight wobble on the plastic motor cover, using a length of wooden dowel to the block could not hear any noticeable unusual sounds from the running motor.

Will check the you tube videos this weekend.

Thanks DM