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Hello guys! I have one problem with my Alfa Romeo 159 1.9 16V, from 2 years my mechanics cant find the problem with my car. When wheather is cold, my car knocking untill the engine temperature goes to 60-70 degrees. I think the problem is in the flywheel. Can you tell is it problem to drive the car like this (if the problem is really the flywheel), because my clutch have more resource and I dont want to waste time and money for just stop this knoking sound for 5-10mins. Is it dangerous for the car to drive it like that? :) Thanks!
VIDEO:
 

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Not an expert opinion, but it sounds to me like your dual mass flywheel is on its way out.

Theres stories of people's dmfs keeping going, for years but it'll only get worse.

Do you get vibrations through the clutch pedal, and a clonk when disengaging the clutch, when its making the noise?

If that is the case, only cure is new clutch, flywheel and slave cylinder, and its not usually a cheap job.
 

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No, there is no any other issue. Only this knocking sound ? Dont have any vibrations and etc. Only when I turn off the car, the sound is lil a bit rough. With sure its the flywheel, but my clutch is in good condition and dont want to change everything if its not dangerous for the car. ?
 

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I'm no expert, but it sounds like all other noises I've heard from a dying flywheel - it should be extra noticeable from where you have taken the video, not so from anywhere else on the car.

I'd say drive it, if you're sure it disappears when warm, worry about it when/if it starts doing it constantly.
 

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Not an expert opinion, but it sounds to me like your dual mass flywheel is on its way out.

Theres stories of people's dmfs keeping going, for years but it'll only get worse.

Do you get vibrations through the clutch pedal, and a clonk when disengaging the clutch, when its making the noise?

If that is the case, only cure is new clutch, flywheel and slave cylinder, and its not usually a cheap job.
How great is the risk of DMF failure resulting in gearbox damage?
 

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Hi

I think that the parts of the DMF are contained so in theory they could fail badly but still 'work' because they have no-where else to go, (that's just my opinion though).

However if you look at why the DMF is there you might want to think again. The theory is that an engine putting a lot of power out at low revs will transfer the vibrations due to the 'thumps' of each cylinder being much more distinct than they are at higher revs when they even out. The DMF 'smooths out' the thumps stopping them from being passed all the way through the drive chain.

The thing that smooths are the springs inside - if they are shot then you are probably in a worse position as now you have two halves of the flywheel banging against each other sending shocks through the transmission as well as the cylinder 'thumps'.

I have no idea what the long term damage would be, I'm just relaying what I read when my DMF came out in a state. I also noticed that the transition from first to second was a lot better after it was fixed, before I had a small power drop between gears.

You don't have to change the clutch plate though I imagine you will always get the advice to do it 'while you are there'.


Cheers
James
 

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I can't say I've seen any cases of gearbox damage from a DMF personally.

like James said, you should really get everything changed when you've got the box off, full clutch kit, flywheel and slave cylinder, possibly rear main seal also, save you having to have the box off again.
 

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If the video is taken from the passenger side it could also be a bad crankshaft balancer. Otherwise, a bad DMF, change it, clutch is cheap compared to the DMF price. I would not drive it like that especially if it is shaking on start up and shut off.
 

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I have seen and experience a total DMF failure where it has ejected parts through the bell housing,prior to this though it will give warning of being in distress as it will be rattling like a good un.

Personally I wouldn’t do just a DMF,it all needs to come off anyway so I would be changing whole kit with a CSC aswell. Can’t think of anything worse than stripping down to do DMF then few months down the line clutch decides to fail.
 

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There have been some instances of dual mass flywheels bending the crank shaft of the engine when they fail.

Not heard of it on an Alfa, but it was on a Vauxhall Insignia 2.0 Diesel which uses a similar engine.
 

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Does not sound like a DMF to me. I've heard couple and they made more of a rattle and less of the knock (like yours has). Also the DMF rattled all the time...hot or cold). DMF failure is a mechanical failure with the two haves and the springs hitting each other to cause the noise. I can't see why it would fade as the motor warms up. That's just my opinion...and I would need to hear it myself (and get the stethoscope on it) to be sure.
 

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As Fruity says, if it's louder in the driver side wheel arch check the crankshaft aux belt pulley. It has a rubber damper that fails and allows the inner to make internal metal-to-metal contact with the outer. To me it sounds more like that, or even a seized alternator one-way pulley (you'll see the aux belt lashing about). The only knackered DMF's I've heard have been skeleton-in-a-dustbin, more clangy.
 

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Thanks for the info. The reason i ask is that when my car was in having a full service and MOT yesterday, i was told that the DMF was 'on it's way out' and that the MOT guy had picked up on it too. (Seems to be based on feeling through the clutch pedal). He said it could fail in 1 mile or 100 miles and if it went, the gear box could be destroyed.

To say i was gutted is an understatement as i only bought the car this summer, after doing MUCH research because of horror stories and the fact that i couldn't afford to buy a problem. I was so scared of driving it that i left it at the garage rather than risk driving home. I've been thinking about it all day, and am considering just selling the car as is. I just can't afford the money that it needs throwing at it, as the service and MOT cost £335.

Does anyone know where might buy the car (i'm guessing a garage that could do the work for the price of parts) because i've seriously had enough and can't trust the car. Thanks.
 

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I know the 'can't afford it' feeling but it's something that wears out after a lot of use. Not specific to AR at all, any car throws the odd big bill. That's basically why cars get cheaper as they age - you either pay a fortune for a new one, plus finance, and burn money on depreciation, or play blindfold pass-the-parcel-of-bills with s/h.

Frankly, if you like the car and it has no other looming issues (rusting front subframe, especially), it will be worth getting it done if you possibly can. It won't need doing again. £1100 is a big lump but if it gets you years of use...

It might be worth PM'ing Dan (Pud237) at Autolusso Penrith, for advice, repair cost, or selling as-is.
 

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DMFs are the weak point on most modern manual cars....which why we generally go solid at work after the first failure...we are caravan dealers so tow a lot so the DMFs get even more punishment. If the DMF fails on my car (151000 miles and counting!)...thats the way I will be going. The point is that DMF failure could occur on virtually any used car you buy...its far from ALFA exclusive....unless you go auto and that has its own set of problems.
 

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I do not think that it is worth it to sell the car if it only needs a dmf and clutch, it is a basic wear part especially on a diesel. If it has other big issues then try to sell it but keep in mind that maybe you wont get any good money for it because it needs repairs or no one will be interested in it since it is "not roadworthy" currently. If some of these (potential) expenses seem very big to you maybe the 159 is not the right car for you since it can chunk a big amount out of your pocket pretty quickly. Get a 156 or similar. No hard feelings, hope you get through with it.
 

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Frankly, if you like the car and it has no other looming issues (rusting front subframe, especially), it will be worth getting it done if you possibly can. It won't need doing again. £1100 is a big lump but if it gets you years of use...

£1100? I've rang around and quotes are around £1500/1600. It's just had 2 front upper wishbones, and i've just been informed that a niggle with the driver's window could fail at any time and requires a £300 regulator and the garage pointed out that when the A/C is switched off (i usually have it on, but when off it's never made a noise before) the compressor 'throws a wobbly' and makes a horrendous noise and is apparently on it's way out too (and apparently is yet another BIG bill.

Unlike many, i can't do any mechanical work myself, so am at the mercy of specialists, and as can be seen on forums- problems can spring up at any time. So it begs the question- do i throw money after money on a car that is still going to need A/C compressor etc and will in no way improve the value of the vehicle, or just cut losses now, walk away and write it off as a bad job. So frustrating- it's just one thing after another.
 

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Oh, he also breaks Alfas, so might have an a/c pump, but if it works and is normally quiet, the clutch on the compressor might just need a squirt of WD40. Or the system needs recharging/fresh lubricant.
 
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