Dual Mass or Solid Flywheel?

[ellsworthbeast]

Hi all,

I got my 406 around a year and a half ago. It had a very noisy dual mass which I had replaced, then I remapped it and I've been very pleased ever since. Apart from the DMF the car has low miles and it's in good nick.

However, over the last few months the new DMF has been squeaking when I shut off the engine. There's no vibration when driving or engaging the clutch, no noise at startup or idle. I want to hold on to my 406 so I'm considering opting for a solid flywheel conversion this time. Has anyone had any experiences with remapped HDis and dual mass/solid flywheel conversions? Will the clutch supplied with the conversion kit stand up to the increased torque? Are these DMFs known to fail with remapped engines?

Finally, whichever option I go for I probably won't be getting the work done this side of Christmas... I hope it's not likely to get worse or fall apart on me?

Thanks in advance!

[Doggy]

Hi & welcome aboard.

The noise might be the dual mass crankshaft pulley, normally you can see rust/dust around the pulley and they tend to get very noisy, reasonably quickly. Worth checking out.

I've had two remapped 2.2 HDi's the first was remapped at about 120k, changed the clutch & DMF at 180k after some clutch slip. The DMF wasn't noisy, but had significant play so I didn't risk re-fitting it. I sold the car about 6k later, but it went to another member's relative and ran fine for another 100k or so.

My current car was on 87k when I bought it and was remapped straight away. I fitted a 6-speed box at about 105k, together with a new clutch & DMF. Again the old DMF has some play, but was working fine. Today it's nudging 202k and is as fit as a butcher's dog.

The DMF works hardest when starting & stopping the engine and I mainly do longish runs which may help. DMF failures are not common on 406's remapped or otherwise.

[ellsworthbeast]

Thanks for the reply.

I'm pretty sure the crank pulley is fine, I replaced it along with the belts & tensioners when I got the car. Also the noise definitely seems to come from the flywheel side of the engine. I had a rotten crank pulley on my 206 HDi which made a clicky noise when running as opposed to a chirp turning off the engine. Maybe I've just got unlucky with this new DMF then?

[GingerMagic]

Hi, welcome.
My 2.2Hdi has a replacement DMF and clutch at around 130K as the remap possibly shortened the clutches lifespan a bit - either that or it was starting to go and I hadn't noticed.
I believe the only downside of fitting a solid flywheel is increased vibrations on tickover - not too bad on some cars but worse on others, maybe maintenance or mileage plays a part in the size of the vibrations.
Some say its the best thing they have done, others say they regret it - not much help to you though.

I would go with what Doggy suggests - if you are a high mileage driver then DMF - if you are stop start then maybe a solid flywheel is better.

[dirtydirtydiesel]

I got my 2.0 110 with 78k on Doggy remapped it to approximately 145bhp on about 85k
Now I use mine to tow a fully laden caravan with a fully laden car my clutch started to slip at 107k
When like this, I nursed it along for another 5k but when accelerating hard ( foot buried )
The D.M.F would shudder & vibrate at peek torque.
When I replaced it the DMF was well worn & it was a different car with the new one fitted

[ellsworthbeast]

Could a solid conversion really be much different to the HDi 90 that comes with a solid flywheel from factory? That's what my 206 had, and I never felt like the 206 vibrated much at all.

[PeterN]

I have an idea that the 90 hp has a different crankshaft, not certain but heard a rumour.

Peter

[Welly]

I thinks its more about smoothness, the DMF works with the engine mounts to protect the cabin from harsh vibration. The 90 may well have balancer shafts on the crank (I don't know) and this would help and therefore remove the need for a DMF. Certain earlier VAG engines had a mixture of balancer shafts depending on vehicle type (the nicer* cars got smoother engines).

I don't know what a 110 would be like with a solid flywheel, in terms of cost I understood that DMF's have fallen in price so it may not be worth risking a disappointing feel to the thing afterwards.