How to diagnose DMF problem ?

L e o

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Hi all,after reading numerous topics and posts regarding the weakness and failiure of many DMF's particularly on the S3 i'm getting a tad paranoid !! But how do you check if its on its way out and are there any symptoms ?
I've got an '07 S3 with 26,000 mls on and is totally standard and it will be out of its warranty at the end of July,only thing i have noticed is that if i rest my foot or gently apply a little bit of pressure on the clutch pedal when its idiling i can feel a "lumpiness" or vibration through the pedal is this a symptom of DMF failiure or is it about to go ? Thanks in advance

A.T.B Leo
 
This is taken from TDIclub.com, good source of technical help and info...


Symptoms include one, some or all of the following.
1. Scratch or soft grind at cold idle.

2. Rattling noise from transmission area (like pebbles in your tranny) Most everyone has this symptom, for some, you can only hear it when the vehicle is in the air with the skid plate removed, for others like myself it is also noticeable in gear with foot on the brake and when just starting out. This noise can be duplicated at will by keeping foot on the brake and shifting in and out of N to R or N to D. Can also be heard in Park. This noise has also been heard from outside of the vehicle when the DMF is getting close to failure.

3. Clunking or hard shifting into first from second when coming to a stop. Others have also reported clunky/hard shifting in other gears.

4. Excessive engine vibration in gear when stopped. Very noticeable

5. Excessive engine vibration at idle in Park. Very noticeable

6. Excessive vibration while driving. Very noticeable

7. Vibrating noise while shutting down.

8. Rattle sound, like metal lines against each other from under car (this has also been attributed to the fuel line rattle TSB)

When it gets to the point where the engine is shaking, then the DMF is coming apart and its time to pull it apart. The looseness in the flywheel spring/weight assembly gets so loose it is actually moving around and throws the balance off on the engine. Its time!!
 
From my personal experience I wouldn't worry about vibration coming through the clutch pedal when you rest your foot on it gently.

All the A3's I test drove in 2005 did it, mine has always done it as have all the A3's I have had as courtesey cars since.
 
Yes though the vibration does vary in strength from car to car, possibly due to how the clutch (and therefore release bearing) has been used (ie sitting at lights with clutch depressed for long periods)?