Hello guys,

Need some input.

This problem began, suddenly, about three weeks ago.

While accelerating; quite heavily; in fourth gear; from around 1500 revs, I was immediately aware that the familiar PD engine "thrummy" sound had been replaced by a sort of old style diesel engine rattle. This only lasted a few seconds, after which the engine note returned to normal as the revs increased.

Since then, this rattle is ever present in all gears while accelerating from lowish revs, but is not audible above 2200 revs. Beyond 2200 revs the engine note is normal.

I'm not too sure if the performance is much affected but I sense the power delivery is not as smooth as previous. This might just be a perception thing on my part, but what isn't, is the rattle.

Any ideas what might be the causing this rattle :confused:

Have you checked the engine bay for anything thats come loose?

Also check the exhaust, sometimes a bolt is slightly loose or a heat shield some where or even a rubbing hanger.

It sounds more like a physical problem then an engine problem based on what you have described.

Hmmm....could be the flywheel. They're known to make these kind of noises when they're shot.

Hmmm....could be the flywheel. They're known to make these kind of noises when they're shot.

Its a Feb 04 with 22K miles. Is there a history of flywheel probs, even at this lowish age and mileage?

I would say accelerating in fourth gear at 1500 rpm is going to do the dual mass flywheel no favours what so ever.

I would say accelerating in fourth gear at 1500 rpm is going to do the dual mass flywheel no favours what so ever.

:iagree: I would never use full throttle below 2000rpm, maybe even 2500rpm. The car just doesn't like it, and as Ross said, the flywheel will not thank you for it. Often, the best way to preserve engine components is find out what driving styles will really knacker stuff up. Full throttle applied so low down is one thing which will not be good (in 4th gear - might get away with it in 3rd, fine in 1st and 2nd)

Thanks to all for the inputs - most informative. I'll return to the subject as soon as I have the dealer's verdict.

I would say accelerating in fourth gear at 1500 rpm is going to do the dual mass flywheel no favours what so ever.

I'm intrigued. Could you explain?

The torque demand is very great at those sorts of revs, thus putting undue stress on the fly.

The torque demand is very great at those sorts of revs, thus putting undue stress on the fly.

Hmm. I still don't follow. The torque goes out to the wheels. The only torque on the flywheel is due to its own inertia. Blipping the throttle while in neutral would put more torque on the flywheel.

I would say accelerating in fourth gear at 1500 rpm is going to do the dual mass flywheel no favours what so ever.

I appreciate you taking the time to respond. I have no knowledge of what a dual mass flywheel is but would appreciate some more info from you as to why the scenario I described would do it " no favours". I don't want to impose, but I'm curious. After all, that's why I joined you guys in the first place.

Yours in anticipation,

BC.

LuK | Products | Dual Mass Flywheel (DMF)

murmini - MINI Cooper Blog : The Dual Mass Flywheel

No Chatter Please: Clutch Service

Hmm. I still don't follow. The torque goes out to the wheels. The only torque on the flywheel is due to its own inertia. Blipping the throttle while in neutral would put more torque on the flywheel.

The links above are good.

In a nutshell the VRS is fitted with a Dual Mass flywheel. The mass of the conventional flywheel is simply split in two, meaning there is a heavier and lighter part. One part continues to belong to the engine’s mass moment of inertia, while the other part now increases the mass moment of inertia of the transmission. The two decoupled masses are linked by a spring/damping system. This system is used to dampen and control the vibrations usually associated with higher power Derv engines.

However, if you run too much through it, it tends cause a vibration which can damage the flywheel and the clutch.

the dual mass flywheel works by dampening out the vibration and noise created by the engine , the name should suggest that it is in 2 pieces , with a damping medium between the 2 bits (a very sticky grease like substance in the case of VAG DMFs) what you are doing by using full power at low revs is making it work to hard due to the torque created low down in the revs , therefore the 2 bits are vibrating excessively , the noise you hear is the knock of the DMF hitting the stops as it can only rotate so far before it does this . damage can occur to the DMF due to this excessive vibration

so do not use full throttle at low revs unless you want to kill the DMF , we change them week in week out at the Ford dealership i work for , £500+ a pop , i would imagine the VAG one is a similar price if not more

LuK | Products | Dual Mass Flywheel (DMF)

murmini - MINI Cooper Blog : The Dual Mass Flywheel

No Chatter Please: Clutch Service

Now I'm beginning to understand how it functions. Thanks.

From what you're saying, I think all cars fitted with a DMF should be accompanied by an instruction manual on driving technique and more importantly, a wealth warning: ignore this manual at your peril - your wealth will be affected!

LuK | Products | Dual Mass Flywheel (DMF)

murmini - MINI Cooper Blog : The Dual Mass Flywheel

No Chatter Please: Clutch Service

Fascinating. I see what you mean now. It is not a flywheel problem per se (i.e. not in its function as a flywheel) but in its function as part of the clutch, transmitting power. Additionally, it is the vibrations between the dual masses that are partly the problem.

As the second flywheel on the drive train is separated from the engine when the clutch is disengaged, that could theoretically lead to a less consistent engine speed compared to having the full flywheel mass on the crankshaft. Does one notice this in practice?

Forgive me, but this kind of thing is new to me also.

Basically you're saying don't flog the car in high gears (4+) with Revs lower than 2K?

Is this the same reason when remapped you've got to be nice to it in 6th?

Hi again,

As I said in the original post; I'd get back with the dealer's verdict.

Here it is: A loose engine cover.

Now that this cover has been secured there is no doubt that there is a change in the engine note. It could be however, that tightening the cover has simply altered the under-bonnet acoustics and that the "rattle" is still there, but less easily identified. You see, I can't quite associate a vibrating cover with the sound I was hearing. Sceptical, or what, eh?

Anyway, I'll monitor over a few days of differing driving conditions, then decide.

I'll keep you posted.

Have you checked the engine bay for anything thats come loose?

Also check the exhaust, sometimes a bolt is slightly loose or a heat shield some where or even a rubbing hanger.

It sounds more like a physical problem then an engine problem based on what you have described.

My thread really attracted some serious interest, including some scary stuff on DMF

implications and driving technique. Perhaps my definition - "rattle" - encouraged this. Your suggestion got little response but could just have been spot-on. I said in my latest post, it was too early yet to decide if the dealer's diagnosis - loose engine cover - was the full answer. However, on an extended drive, tonight, I must say, the rattle seems to have ceased. I'll continue to monitor.

I've got a 2003 SEAT Alhambra fitted with the same 130 BHP engine and DMF - these were subject to a recall because of DMF failure and mine was replaced at 18,000 miles despite not having any issues. Just out of interest, what revs should owners use in each gear?

My thread really attracted some serious interest, including some scary stuff on DMF

implications and driving technique. Perhaps my definition - "rattle" - encouraged this. Your suggestion got little response but could just have been spot-on. I said in my latest post, it was too early yet to decide if the dealer's diagnosis - loose engine cover - was the full answer. However, on an extended drive, tonight, I must say, the rattle seems to have ceased. I'll continue to monitor.

even though your rattle seems to have gone , please take heed of the previous warnings re the DMF and full power from low revs , they are not common for going but it won't last forever if loaded excessively

I've got a 2003 SEAT Alhambra fitted with the same 130 BHP engine and DMF - these were subject to a recall because of DMF failure and mine was replaced at 18,000 miles despite not having any issues. Just out of interest, what revs should owners use in each gear?

AFAIK , this recall which also affected the Ford Galaxy and VW Sharan , was for a flywheel made by a different manufacturer than the one fitted to the Fabia VRS

a complete clutch kit and DMF were fitted

even though your rattle seems to have gone , please take heed of the previous warnings re the DMF and full power from low revs , they are not common for going but it won't last forever if loaded excessively

Thanks for the advice. I've already taken on board all of the inputs on rpm and full throttle.

I have a PD100 (rather than a vRS) - but am wondering if I have the DMF problem mentioned?

I notice two things:

* vibration when pulling away from rest. It gets worse if, for instance, I'm in a traffic jam so have to keep starting & stopping

* vibration in the steering wheel when the engine is "Pulling" in 5th. This seems to get worse when going up hills on motorways, for instance.

If it wasn't for the 2nd one I'd suspect I needed a new clutch - but I've not noticed any slippage.

Car is totally unmodified, but I've done 200K so plenty of time to have worn out a component or two...

Do PD100s have a DMF as well, and am I looking at needing a new one? What do they cost (bearing in mind the car isn't worth a lot)?

:confused: I have 56reg Fabia VRS my engine seems very vocal, ie noisyonly had few months. On test drive in in other VRS it seemed much quieter any ideas or is it normal for this vehicle. thanks