Increasing the life of a dual mass flywheel

[VeeFource]

So it's looking like the dmf on my new Ibiza FR might be starting to fail despite the car having only done a mere 30k. I've recently noticed a rattling sound with the clutch roughly in it's biting position when in neutral and especially when the car's still cold.

I only bought the car 2 months ago so luckily it's still got a month left on the warranty which should hopefully cover this, but it's still pretty shocking given the car's just over 3 years old and with such low mileage. I can't speak for how it's been driven up till 1000 miles ago but this has still got me wondering about my driving style and whether it's likely to happen again with the next one.

Having done some reading up it seems there are two things that help kill dmfs, one is high torque at low revs and the other is heat build up. Given my commute features lots of lovely traffic lights, this has got me pondering the following:

1. Is it better to pull off with higher revs to reduce reduce the vibration spikes seen by the dmf or lower revs to reduce heat build up from slipping the clutch less?

2. I sometimes save fuel by increasing my slowing down distance and going into neutral between my down changes from 3rd to 2nd etc. But this increases the amount of time the engine is idling which means of course it spends more time at lower revs. But then it's not loaded like it would be if I were driving normally, so which is worse?

3. Does blipping the engine on the down change cause dmf killing vibes or does it help given it reduces clutch heat build up?

There's really not a lot of point in going diesel if I'm going to have to get a new dmf every 2 effing years!

Thanks in advance :-)

Edited by VeeFource on Sunday 15th December 11:16

[Mr GrimNasty]

I've done a 100K without giving the DMF a single thought, it's been faultless, and I do every thing 'wrong'. Either yours was sub-standard from new, thrashed to death, or massively clocked. Whatever, it is just bad luck/unavoidable. Like any other random car problem, there is no reason why a replacement will need any special driving consideration or not last 100K+. Loads of petrol cars have DMFs these days (although they seem to lead an easier life).

[motco]

For what it's worth, I try to avoid the lower end of the rev range where the individual firing pulses can be felt in the cabin. The logic is that if that occurs then the full range of rotational movement must be taking place within the flywheel parts which, in turn, must stress the flexing parts. Avoid labouring and avoid driveline shocks. My last diesel (Mondeo 2.0) had 130,000 miles on its original flywheel. Admittedly I was responsible for only half of those.

[VeeFource]

Mr GrimNasty said:

I've done a 100K without giving the DMF a single thought, it's been faultless, and I do every thing 'wrong'. Either yours was sub-standard from new, thrashed to death, or massively clocked. Whatever, it is just bad luck/unavoidable. Like any other random car problem, there is no reason why a replacement will need any special driving consideration or not last 100K+. Loads of petrol cars have DMFs these days (although they seem to lead an easier life).

What car have you got? They seem to fair better on less powerful diesels, though it's not like mine's a leon FR. This car has only had one lady owner (which I believe given all the shopping receipts I've discovered) but may well have been laboured at low revs. It hasn't been clocked which I can tell from the finish on the controls let alone the history. As you say, it may just be bad luck, but if I can make my own luck i'd be more optimistic

Edited by VeeFource on Sunday 15th December 11:33

[mph999]

I personally have always gone for the lower end of the revs when pulling away (reduce wear on clutch), but do avoid using only the clutch to creep in traffic (they really really hate that apparently).

I never, ever, 'slip' ride the clutch.

So far, just on about 50000 miles, same clutch, same DMF and no evidence of any issues.

For what it's worth, my father drives in a similar manner to myslef, he's on a bit over 70K on the same clutch/ DMF.

[Jamesemt]

With reference to point 2 - you don't save fuel by going into neutral, you save fuel by using the gears to slow down as the car then goes into fuel cut.

I've done 91k on standard clutch/flywheel and I'm remapped. Wife had a Fab vrs 130 which I wrecked the clutch in 20k, by lugging it from low revs and feeling the huge torque wave as it came on boost.

[motco]

Jamesemt said:

With reference to point 2 - you don't save fuel by going into neutral, you save fuel by using the gears to slow down as the car then goes into fuel cut.

I've done 91k on standard clutch/flywheel and I'm remapped. Wife had a Fab vrs 130 which I wrecked the clutch in 20k, by lugging it from low revs and feeling the huge torque wave as it came on boost.

Many say that it's more economical to use the over-run to decelerate - and I see the logic. However consider this: if you drop into neutral to slow the car naturally you do it earlier than if you use a trailing throttle. Whilst this does mean fuel is being used at a tickover rate, it is also true to say that you have been on power longer if you use any form of braking albeit engine or friction. Do you use less driving fuel by dropping into neutral early and idling, or by driving longer and 'braking' more by engine retardation? It would need either more data than we have from the engine designers, or a series of trials under controlled conditions to gain the answer.

Back on flywheel care, I try to use as little revs as reasonable to move off, and do it very gently until the clutch is engaged fully and the revs are c.1500 before then applying 'proper' power to continue. I admit to manoeuvreing on idle but carefully so as not to noticeably drop the idle revs. My 1996 Mondeo 1.8TD had well over 200,000 miles on the original clutch so I must be doing something right! The 2.0 TDDi is still running with its new owner on the first clutch too. Not sure if the Mk1 had a DMF but the Mk3 certainly did as does my 2.2 X-Type.

[HustleRussell]

Didn't SEAT go through a period when they were known for premature DMF failure? I seem to remember hearing a lot of this about 5+ years ago. I think the replacement flywheels always lasted better.

With respect to making them last longer, I always preferred to use more revs and slip than labouring the engine. I found myself adjusting my driving quite a lot in an effort to preserve the DMF. It's one of the reasons I went back to petrol after that car, even though I didn't actually suffer a DMF failure.

[wolf1]

I abused the carp out of the clutch in my last Vivaro, holding it on the clutch at junctions, sidestepping it, towing 2 tonne multiple times a day, reversing round tight uphill corners to the point of the clutch stinking etc. It had roughly 190000 on it's original clutch and dmf and i'd had it from new.

There's no real apparent reason for failures as yet, I could only put them down the manufacturing/design defects.

[Condi]

Jamesemt said:

I've done 91k on standard clutch/flywheel and I'm remapped. Wife had a Fab vrs 130 which I wrecked the clutch in 20k, by lugging it from low revs and feeling the huge torque wave as it came on boost.

That shouldnt destroy a clutch. Once it is engaged then it wont/shouldnt slip and your more likely to stall than have any slip.



Anyway, what I dont get about these DMF's is that they are there to protect the engine/gearbox from shocks through the transmission. How come then they dont have them on tractors and plant gear? A 400hp, 12 litre, tractor will send massive shocks through the transmission when pulling hard, and yet they dont have a DMF? Okay, the whole unit is bigger, but proportionally not massive.

[budgie smuggler]

Condi said:

That shouldnt destroy a clutch. Once it is engaged then it wont/shouldnt slip and your more likely to stall than have any slip.



Anyway, what I dont get about these DMF's is that they are there to protect the engine/gearbox from shocks through the transmission. How come then they dont have them on tractors and plant gear? A 400hp, 12 litre, tractor will send massive shocks through the transmission when pulling hard, and yet they dont have a DMF? Okay, the whole unit is bigger, but proportionally not massive.

Isn't it more to help the NVH for the passengers? Probably not as much of an issue on plant.

[ohtari]

VeeFource said:

What car have you got? They seem to fair better on less powerful diesels, though it's not like mine's a leon FR. This car has only had one lady owner (which I believe given all the shopping receipts I've discovered) but may well have been laboured at low revs. It hasn't been clocked which I can tell from the finish on the controls let alone the history. As you say, it may just be bad luck, but if I can make my own luck i'd be more optimistic

Edited by VeeFource on Sunday 15th December 11:33

That's probably your answer. Most "one lady owner" cars I've experienced have been treated with no mechanical sympathy or care.

I really don't know why it's still considered a selling point!

[VeeFource]

motco said:

Many say that it's more economical to use the over-run to decelerate - and I see the logic. However consider this: if you drop into neutral to slow the car naturally you do it earlier than if you use a trailing throttle. Whilst this does mean fuel is being used at a tickover rate, it is also true to say that you have been on power longer if you use any form of braking albeit engine or friction. Do you use less driving fuel by dropping into neutral early and idling, or by driving longer and 'braking' more by engine retardation? It would need either more data than we have from the engine designers, or a series of trials under controlled conditions to gain the answer.

Bang on! The amount of fuel used to idle the engine is so little compared to maintaining a higher speed for longer. Cars with high enough mpg meters will show 999mpg when coasting at higher speeds. The rate of decelleration when coasting is also so low that you've normally only lost 5-10 mph over 200 yards so if you use the engine braking in addition to this (manually braking as little as possible) then you'll have saved more fuel overall.

Thanks for all the other posts guys, feeling a bit better about the new car as I love it in every other way. Any thoughts on rev matching though?

[VeeFource]

Condi said:

Anyway, what I dont get about these DMF's is that they are there to protect the engine/gearbox from shocks through the transmission. How come then they dont have them on tractors and plant gear? A 400hp, 12 litre, tractor will send massive shocks through the transmission when pulling hard, and yet they dont have a DMF? Okay, the whole unit is bigger, but proportionally not massive.

Have you ever used one of those gearboxes though? They're not exactly slick and a car equivalent would undoubtedly be a big heavy thing, so would probably get slated in the new car reviews

ohtari said:

That's probably your answer. Most "one lady owner" cars I've experienced have been treated with no mechanical sympathy or care.

I really don't know why it's still considered a selling point!

Quite right, it did put me off in some ways, but then at least I knew it was unlikely to have been chipped.

I doubt the ridiculous eco gear change indicator helped either. Anyone following that idiotic advice would be idiling in 6th in a 50 zone..

Edited by VeeFource on Sunday 15th December 13:05

[dfen5]

Just my 5p worth but the warranty won't cover that DMF - or I'll be amazed if it does.. Some garages won't fit a clutch to a dmf car without replacing it due to warranty issues with proving the clutch they fitted a few miles ago isn't playing up.

Edited by dfen5 on Sunday 15th December 13:18

[Disco You]

Is is possible/ what are the consequences of fitting a normal flywheel to an engine that comes with one as standard? I'm talking about the fiat 1.9 Diesel engine as fitted to Vauxhalls and Saabs in particular.

[VeeFource]

dfen5 said:

Just my 5p worth but the warranty won't cover that DMF - or I'll be amazed if it does..

Why wouldn't it? It has occured to me they might try and say it's normal seeing as it still drives ok, but it's not a serviceable item and it's clearly not right from the noises it's making.

Disco You said:

Is is possible/ what are the consequences of fitting a normal flywheel to an engine that comes with one as standard? I'm talking about the fiat 1.9 Diesel engine as fitted to Vauxhalls and Saabs in particular.

It's not recommended unfortunately. It's partly there to protect the gearbox from high torque spikes generated by modern engines so you can ruin your box and sometimes end up with bad drivetrain rattles

Edited by VeeFource on Sunday 15th December 13:25

[ohtari]

VeeFource said:

dfen5 said:

Just my 5p worth but the warranty won't cover that DMF - or I'll be amazed if it does..

"Why wouldn't it? It has occured to me they might try and say it's normal seeing as it still drives ok, but it's not a serviceable item and it's clearly not right from the noises it's making."

Unfortunately a DMF is usually regarded as a "wear and tear" item, just the same as a clutch, brakes or tyres.

It will depend on the dealer though.

Best of luck!


Oh, and don't even think of fitting a solid flywheel, a quick search will tell you all you need to know!

[egor110]

mph999 said:

I personally have always gone for the lower end of the revs when pulling away (reduce wear on clutch), but do avoid using only the clutch to creep in traffic (they really really hate that apparently).

I never, ever, 'slip' ride the clutch.

So far, just on about 50000 miles, same clutch, same DMF and no evidence of any issues.

For what it's worth, my father drives in a similar manner to myslef, he's on a bit over 70K on the same clutch/ DMF.

How do you crawl along in traffic or deal with a junction uphill?

[Matthen]

ohtari said:

Unfortunately a DMF is usually regarded as a "wear and tear" item, just the same as a clutch, brakes or tyres.

It will depend on the dealer though.

Best of luck!


Oh, and don't even think of fitting a solid flywheel, a quick search will tell you all you need to know!

Not true - a sprung clutch and solid flywheel combination can, in some cases, replace the dual mass flywheel. My car is an example of this - same engine in a transit has no dmf, thus, you can replace it with transit parts.