The Superb has been in the workshop for a week as I was getting a rattle when I started - thought it was something loose but it turned out to be a dual mass flywheel. Not quite sure what it is other than it needed the gearbox to be removed. They had to replace the started motor as well. All covered by warranty as I suspect it would have cost well over £1k otherwise. What is the dual mass flywheel?

 

One thing I asked them to check was the heated rear window as it takes ages to clear but they said a couple of the elements have been scratched so not possible to get sorted on the warranty. I know you can get some conductive paint to repair this but has anyone used it and if so did it work? Is there a company out there that do these repairs?

 

Any help would be appreciated

 

Martin

For the DMF, it's the fly wheel.  A fly wheel is a heavy ring shaped mass that goes between the engine and the gearbox.  It's used to smooth out the 'pulses' of torque generated by the engine.

 

Think of a large heavy ring of steel that is free to spin around it's axis.  If you hit it on the edge from a tangent, with a hammer it will start to rotate.  That's basically how your engine is delivering torque, in lots of short hammer pulses.  These pulses are smoothed by lots of things:  the mass of the crankshaft, a counter-rotating balance shaft (not sure of the CFFB engine has one of these), by firing the injectors multiple times (possible on a common rail engine, not possibly on the PD engines) and then the fly wheel.

 

It also has a ring of teeth around the edge that the starter motor engages with to start your engine.  If you car has a manual gearbox, it's also the first surface that the clutch plates 'rub' against.

 

To try to reduce diesel vibrations, they have a two part flywheel.  It's kind of like a small diameter flywheel within a large diameter flywheel, connected by rubber/springs.  VW in general has a history of these springs letting go and blowing holes in the bell housing.  Glad yours was sorted under warranty and you caught it before it failed fully.

 

Can't speak for the rear window, but does the whole window take ages, or is it just missing some parts?  I would expect the latter if some elements have been scratched.  I've never used the conductive paint but any reputable car window company should be able to replace the whole window including the heater strips.  I don't know how it works over there buy on my car insurance here in AU I get a free window per 2 years (it does say "windscreen" but I've used it previously to have a hail damaged rear window replaced) without any excess.  

I first used the conductive paint about 40 years ago on a Fiat 127 to repair the elements on the heated rear window after I bought it second hand from a newspaper ad and it worked fine. 

 

I've also used it at work to repair my desktop mains operated calculator (a big one with machine roll).  The sliding switches for functions, such as how many decimal places you need, were worn through on the printed circuit board underneath and the paint brought them back into operation. 

 

I've still got the same paint bottle somewhere, but I don't know if it's any good still.

A couple of videos here, which will give a graphic description of what a DMF is and does.

 

http://www.youtube.com/watch?v=DbvP5EvpUbA

 

http://www.youtube.com/watch?v=YnaXB8q3uzQ

 

re. conductive paint, yes, I have used it successfully to repair HRW elements. I have also soldered the connectors back on to a window when they have detached - note, you will then need a good epoxy glue to stabilise the connector, or it will break off again.

 

NB - how do you embed videos on this forum?

Conductive paint... used many times with great success.

Repaired Screen heaters, Printed circuit boards, Battery connectors etc

See....

Available on Ebay, search for...  conductive silver paint

You can also buy conductive glue and epoxy

Many thanks Guys - useful info

Watched the DMF videos - does the clutch get replaced at the same time as the DMF or is it only if needed?

Watched the DMF videos - does the clutch get replaced at the same time as the DMF or is it only if needed?

 

More often than not, the clutch would be replaced. 

 

1. It's a lot of hassle to take the gearbox out, and then have to do it again for a clutch.
2. Replacing a flywheel without renewing the clutch is like changing your brake discs without replacing the pads.

Ksr

 

Ah yes but would the dealer have done this under warranty. If I had been asked I would have paid any extra to have it done. I guess I will have to ask the next time I go in

 

Martin