Defective ZMS: Effects and Troubleshooting

Hello everyone!

I'm curious again. Has anyone had experience with defective dual-mass flywheels? How does such a defect manifest itself?
Could there be a strong torsional vibration in the powertrain that could be misinterpreted as partial load surging or a pump defect?

I am already curious about your answers .

Regards,
Alex.

Hello, Volkswagen's PD engines use a dual-mass flywheel.
In case of a defect, a slight vibration may occur at idle, which is similar to a malfunction of one or more pump elements.
In a more advanced stage, I could also imagine experiencing some jerking or hesitation in the partial load range.

@mersente:

Quote:

... in the PD engines of VW, a dual-mass flywheel is used.

Only on the PD models? In my opinion, most of the VP-TDIs were also equipped with this, or am I wrong?

Regards,
Alex.

Only on the PD models? IMO, most of the VP-TDIs were also equipped with it, or am I wrong?


Yes, but not all of them are AFN.
The 1Z definitely didn't have one. My AFN does.

I've also been wondering about the dual-mass flywheel (DMF) issue a few times. I don't know if you remember, but I recently had a clutch failure where the internal teeth of the friction disc came loose. I suspect this might be due to excessive vibrations from the DMF. Now I'm experiencing a lot of vibrations in the partial load range, around 3000 RPM. I have no idea what's causing it.

Hello, this isn't just happening with PD motors, but it's been an issue since then.
If you ever go to a friendly mechanic and want a new ZMS (presumably referring to a clutch), you'll see that it typically needs to be replaced about 3-4 times, which is quite strange, isn't it?
So, the problems are known.

Hi there,

I had a faulty dual-mass flywheel (DMF) and didn't notice anything while driving. Here's the story: I installed an AFN engine from a Golf Mk3 into my van, including the original DMF. Shortly after the installation, I started hearing terrible noises from the engine bay. It was very loud, like large ball bearings bouncing around inside the engine. I turned the engine off and on, and everything was okay. It didn't happen again. I didn't think much of it, because the bell housing had to be modified to make room for the DMF, and I thought something might still be obstructing it. I suspect that the DMF failed during that "bouncing" noise. I then drove another 20,000 km with it, without any problems. Then, the transmissions were supposed to be overhauled and adjusted. When we removed the transmission, we found the faulty DMF.
The springs were broken, and the remnants had already worked their way to the outside. The ZMS (presumably a component) was blocked in its fully extended position, and could only be removed by flexing the connecting rods.
Allegedly, there was a (faulty?) series that didn't have the plastic filler. Mine definitely didn't have any filler. The motor is from the beginning of 1997.
I now have a central locking module (ZMS) from a Sharan installed, and I haven't had any problems for the past 50,000 km.
By the way, I never received a response from Luk regarding my inquiry about the use (not the damage) of the ZMS in the bus.

Greetings.
dieter

Hi.

My AXR colleague had a faulty dual-mass flywheel!

His workshop spent a long time troubleshooting the issue because they initially suspected problems with the PD elements (which could also have produced implausible readings).

Then they initially swapped out 2 PDs, but it's still garbage.

At some point, they replaced the clutch, and lo and behold, it started working again.


The workshop had the car for several days, and my friend didn't have to pay anything.

Lucky you!

m;

Hi!

In another thread, where we were discussing the unstable idle behavior of the PD injectors or the AXR engine, I already described my problem. Briefly: Even after replacing all the PD injector elements and updating the engine control unit to the MQ software, I still sometimes experience a slight 'shaking' that is transmitted to the body and thus to the interior.

I'm now reading that it could also be due to a faulty dual-mass flywheel. Sorry, but I don't know much about it. I'd like to know where that part is located, what it does, and how much a replacement would cost.

Best regards,
VipViper2000

Hello, the dual-mass flywheel is bolted to the crankshaft, and the clutch is mounted on it. Its purpose is to compensate for changes in engine speed.
Depending on the design, for example, there are parts that are screwed to the crankshaft and parts that are screwed to the clutch. These parts can be connected by springs or rubber. It is possible to twist both parts relative to each other to a certain extent. This compensates for vibrations or changes in speed.

I estimate the price for the ZMS (flywheel) and clutch to be around 600 euros.
The installation time varies depending on the model, but it's approximately 240 minutes.

Hmm, so that would already be around 800 euros. And I'm sure VW wouldn't just install the part 'blindly,' hoping that the slight wobble would disappear afterward, would they? What about warranty coverage in this case?

VipViper2000

Yes, it depends on the age of your car. If it's older than 3 years, it's unlikely that the dealership will offer any goodwill gestures.

Okay, so that's EZ 08/01. Anyway, I'm going to go there sometime this week because I want to install an armrest and I still need the screw set for that. I'll ask them what they can do for me.

Best regards,
VipViper2000