# X250 3 litre Comfortmatic - Clutch Slip or Comfortmatic Problem?



## BorisBolero (Aug 10, 2009)

Your advice would be much appreciated please.

My 2008 Fiat X250 3litre comfortmatic 32,000 miles, has inthe last thousand miles or so started to intermittently slip its clutch when accelerating at low revs in 4th to 6th gear. Revs also briefly rise and then fall again after it has automatically changed down to tackle a hill in 3rd to 5th gears. Is this a fault with the clutch or with the comfortmatic gear changing do you think? It has been driven gently (had it from new) but scaled many mountains in the Alps, Norway and Scotland. If it's a clutch problem is it likely the dual mass flywheel is also caput?

Any comments please.


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## Dill (Jun 3, 2010)

From what you have described (Clutch Slipping) yes it will need a new clutch and a duel mass unfortunatly.

Dill


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## Pudsey_Bear (Sep 25, 2008)

I don't understand why it would need a new fly wheel.


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## flyinghigh (Dec 10, 2012)

Kev_n_Liz said:


> I don't understand why it would need a new fly wheel.


Simply put the duel mass flywheel has a moving section that reducers vibration when changing gear, consequently it wears and starts to rattle, it would be silly to not replace it when changing the clutch, I have seen them break up when worn and do considerable damage to Bellhousing/ gearbox,
Totally false economy not to change it when the gearbox is out,


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## BillCreer (Jan 23, 2010)

My take on Dual mass flywheels is that they are there to cushion your gear change / clutch action with a big spring. It does work, as the gear change on my Honda CRV is the smoothest I have ever encountered. I can see that if your clutch has been slipping for some time and generating a lot of heat then the heat will do damage to the big spring but if that is not the case then you have to do the maths as they are very expensive.
We are not talking like for like but if the clutch were on its way out on my CRV then I would not change the DM unless I had seen or heard signs that there was a problem. If I came across a cheap one though, I would.


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## hogan (Oct 31, 2006)

Also to add if it has a clutch slave cylinder change it as well it's located inside the bell housing. 
That's progress for you.


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## eurajohn (May 9, 2005)

It sounds to me from the symptoms you describe to be a clutch problem.
Whether you do the job yourself or have it done definitely change all 3 clutch components.
As to the dual mass flywheel there are many compression springs mounted radially within the unit, if you or whoever does the work checks Fiat technical, there are set out tolerances as to what is acceptable radial movement.
If in doubt replace it anyway, a straightforward job when box is out; their purpose is to dampen drive chain resonance, which, as a by product helps to smooth gear changes.


.


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## Mrplodd (Mar 4, 2008)

The purpose of a dual mass flywheel is to prevent premature failure of the drive train.

A modern diesel engine produces a lots of power peaks (multijet engines have FIVE fuel injections per power stroke, yes really) these peaks in power are transmitted down the drive train and, if not damped out, will soon knacker the gearbox. SO...... the makers fit a DMF, which is basically TWO flywheels, one inside the other, between the two are a set of hefty springs set radially (in line with the flywheels rotation) these springs absorb the peaks in power that would otherwise damage the gearbox.

They are not a cheap item (about £700 I think) the biggest single cause of failure is apparently excessive heat. This heat is generated by friction when the vehicle is held on the clutch on a gradient. Its takes VERY little time to build up vast amounts of heat by doing this. The heat gets into the springs and destroys the temper (springyness) of them. There is no cure, the ONLY remedy is (expensive) DMF replacement. 

Moral of the tale is that you should only ever hold your Mh on the clutch alone MOMENTARILY and by that I mean one or two seconds ONLY !!! remember if you are holding it on the clutch you are attempting to stop something in the region of 3.5 -4.0 tons sliding down hill !!! That puts a HUGE amount of heat and wear onto/into your clutch.

ALWAYS ALWAYS ALWAYS USE YOUR HANDBRAKE, NEVER EVER EVER YOUR CLUTCH !!!!!!!!!!!!!!

From the description at the start of this thread its clutch slip. 

I think there is a problem with comfortmatic gearboxes, drivers THINK they are a different kind of (torque converter style)fully automatic epicyclic gearbox (Google search will explain) which you can hold on the throttle on a gradient, when in fact they are actually a robotised fully manual gearbox with a standard friction clutch that is all operated for you, so if you hold it on a hill on the throttle you are actually slipping the clutch all the time, with inevitable consequences.

Andy


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## wobby (May 1, 2005)

Mrplodd is absolutely right, I have one of theses gearboxes on my Hymer and I never ever hold it on the clutch. The latest version of these vehicle now have hill hold which is in my opinion a must for this type of setup. 

Wobby.


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## Pudsey_Bear (Sep 25, 2008)

Just another part to go wrong and richen the manufacturers pockets, we've manged for decades with the springs in the friction plate itself and I've never had any problems, and never had to replace a flywheel, and only a clutch once, not progress to my mind, some of the crap on modern engines doesn't actually justify it's place.


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## Mrplodd (Mar 4, 2008)

MeV

I would point out that just about every engine manufacturer fits a DMF these days. 

They cost a lot of money to produce and are a complex bit of engineering. 

Manufacturers spend a lot of time trying to save pence per vehicle.

Do you really think they are going to fit such an expensive item if it's not required?? I suspect that the engine makers know a bit more about what is required than those of us who just use them do don't you??

I certainly agree that there SEEMS to be an awful lot of complexities attached to modern Diesel engines but.......... They are marvels of engineering. I have a 2.2 litre Mazda 6 estate, it's a large car yet even though it produces 175 BHP I regularly get just over 60mpg on a distance run. Incredible in my view but that figure is only obtainable due to the incredibly minute control that the electronics etc exert over the engine function (AND it produced very little pollution so is cheap VED as well!!

(Trouble is the expense if anything ever goes wrong, the standard fault finding method seems to be trial an error of component replacement until the fault is rectified) 

Andy


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## eurajohn (May 9, 2005)

Kev_n_Liz said:


> Just another part to go wrong and richen the manufacturers pockets, we've manged for decades with the springs in the friction plate itself and I've never had any problems, and never had to replace a flywheel, and only a clutch once, not progress to my mind, some of the crap on modern engines doesn't actually justify it's place.


Kev, as I've said many times before, "everyone is entitled to their opinion" (even if it is wrong :smile2
It is known in the modern world as progress. 
Why do you think each new version of whatever, is better in some respect than the old one?, progress and development.
Anyone that has driven a 3 litre Fiat will agree how smooth it is compared to the older 2.8, in part that is as a result of items such as the dual mass flywheel.

Consumers (you and me) continue to demand, bigger, better, more efficient etc. and as long as we do the manufacturers will continue to research and develop.

The only consumers that are prepared to accept less than the best are those that have no access to better, that's not where we find ourselves at the moment.

.


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## leseduts (Jun 3, 2008)

On the Comformatic, what is meant by holding it on the clutch. If in manual does that mean taking it into neutral whilst stationery and pulling on handbrake even when stood at traffic lights?


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## camoyboy (May 9, 2005)

Just had the clutch assembly, dual mass flywheel and slave cylinder changed on our 2008 3L manual at 43,000 miles after having similar issues. I had the job done at our local FIAT Professional garage. I have to say I was very pleased with the service they offered, they called me in to inspect the old parts, (the flywheel was shot with 45mm movement at the rim,should be no more than 20mm), and they showed me the new parts which were the updated version. £1420 all in, I guess the comfortmatic may have more labour time for the hydraulics? 

Colin


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## Mrplodd (Mar 4, 2008)

Les

The comfortmatic is exactly the same as a fully manual system EXCEPT everything is done for you. 

If you stop on a hill with a manual you can hold it from slipping backwards on the clutch (bad habit indeed!!) With a comfortmatic if you come to a halt and then apply a little throttle to "hold" it stationary the electronic wizardry does exactly what you would do, IT SLIPS THE CLUTCH. 

The vital thing to keep sight of is the fact that Comfortmatic is not an automatic gearbox in accepted sense of the word "automatic" it is EXACTLY the same components as a normal manual transmission, its just that ALL of the actions (dipping the clutch, selecting the gears and re-engaging the clutch) is done for you. 

You still have a fully manual gearbox and a fully manual clutch between the engine and gearbox NOT a torque converter !!!

Andy


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## leseduts (Jun 3, 2008)

Mrplodd said:


> Les
> 
> The comfortmatic is exactly the same as a fully manual system EXCEPT everything is done for you.
> 
> ...


Thanks,
Can I leave it in gear, apply the handbrake and not touch the throttle, or do I need to put it in neutral. We had a Sprintshift prior to the conformatic and It never crossed my mind that I could be riding the clutch.


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## Mrplodd (Mar 4, 2008)

Les

Best practice is certainly to take it out of gear and apply the handbrake whenever stationary. However realistically that's not always possible so it's OK to leave it in gear whilst stationary PROVIDING you don't touch the throttle. (Just like you would do with a "normal" manual transmission) 

I am rather disappointed that neither Fiat or Mercedes make it clear to people that Comfortmatic/Sprintshift is NOT a "proper" automatic and should certainly NEVER EVER be held on a hill other than by the handbrake. It's normal practice to hold a vehicle on a hill if it's fitted with a fully automatic gearbox because there isn't a clutch to wear out.

Andy


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## Mrplodd (Mar 4, 2008)

Colin

The labour time is about the same as for a standard clutch change (which is what it is) the price you paid would seem to be about right for a main dealership. The DMF is around £750 and the clutch components about £300 so I don't think you were seen off !!!

Andy


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## BorisBolero (Aug 10, 2009)

Thank you all for your helpful informative replies, good to have a wealth of knowledge out there.


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