Just don't drop the pedal to the floor, instead start accelerating and then increase the amount of welly you give it gently until you're speeding up as required

Or drop down a gear so revs are above the peak torque

Chris

Mine's done this since I had my Revo remap a few weeks ago. I assumed it was the clutch slipping or something and was worried as the car has only done 6k miles, but this dual mass flywheel thing sounds like what it is. It's a sort of duh-duh-duh-duh-duh sound and i feel it more through the chassis and pedals than through the steering wheel. Does it a little in 3rd gear but mainly in 4th when booting it from lower revs. Will use lower gears to avoid it in future...

What sort of damage can be done to this part of the engine?

Or drop down a gear so revs are above the peak torque

Chris

A very fair & good point

Hi guys,mine does this between 2500-3000rpm in 4th & 5th under load very noticable going up hills been into skoda they cant find a problem going back in next week is there any thing i should tell them to look at in particular

oh yea my car is still standard should it do this!

cheers chris

Just don't drop the pedal to the floor, instead start accelerating and then increase the amount of welly you give it gently until you're speeding up as required

My definition of "feed the power in" - appols if this is technicaly incorrect

Just put it the way I thought of it at the time, ;)

Best way to avoid it is to drop down a cog before planting it.

Just to clarify the DMF (I had a look at it a bit as was concerned about it due to amount of expected power from work I'm doing/getting done)

Flywheel is a heavy disc which spins and it resists changes in it's speed by being heavy. A single mass one is basically just a single disc. A dual mass one has two of these discs, one side 'clutch end', one side 'engine end'. Force is transferred between the two discs by springs that are attached inbetween the two discs. The springs are heavy-duty as they have to transfer the torque (effectively) from engine flywheel to the other one. The springs are designed to deal with a certain amount of force until they're at full stretch. When that happens the engine disc, which vibrates with the punches of the engine, will hit the max extention on the spring, then transferring that punch through to the second flywheel without the spring doing any absorbing. I think that then causes the punching noises.

Not 100% on how the springs are protected against overstretching but if there is some kinda 'end stop' it would make it stop flexing abruptly.

Remember I'm not a qualified mechanic etc so if someone more knowledgable comes along please feel free to correct/add accordingly

I had a new fly wheel fitted under warranty two weeks ago. The only difference now is that the viberation happens between 2000rmp and 2500 rpm instead of 1500rpm and 2000rpm . The dealers line was "its the nature of the beast " there is nothing wrong with your car.

Well well this is certainly one for not modifying your car - imagine going for a 400 mile treck and having to put up with this for hours on end.

What a rubbish drive vibrations etc and not able to use all the power & torque you have given that what the hell is the point?

Much worse driving enjoyment, inability to use all the torque available, higher emmissions, shorter engine life (due to higher engine stress).

This sounds a lot like the problem I was asking about a few months back, which turned out to be a cracked engine stabiliser. It didn't sound high pitched, but it did sound like the "duh-duh-duh-duh-duh" described by a recent poster. I drive an un-modified 1.9 TDi, so never experienced it in any gear other than first (when taking off from stationery) or second (under heavy acceleration uphill or in the wet). A local garage replaced both parts for £150, incl. labour, and it's cleared up.