Idle vibration on 2.0 TDI 4V engine with Siemens PPD 1.5

Hi everyone,

My Passat B6, a 2008 model with a 100kW 4-cylinder engine and 1.5 piezo injectors (PPD1.5), and a DSG transmission, is experiencing problems at idle with 150,000 km on the odometer. Here's the error description:

Sudden vibrations only during idle. Relatively rare during warm-up, but more frequent with a fully warmed engine. It's as if after a period of idling with vibrations, the next idle phase is completely smooth – suggesting a rather sporadic or random error. This occurs regardless of outside temperature, engine temperature, load conditions (i.e., it happens both after a hard acceleration and during city driving), climate control status, generator load, idle speed (700-900 rpm), and EGR rate.

"If there are vibrations when idling, they tend to be more harmonic – but you get the feeling that the entire car is shaking. Acoustically, everything is completely fine. Otherwise, the car is free of any other issues." Error memory is clear.

The LRR integrators are all close to zero, and the injection amount is stable, which is why I believe that these LL oscillations are not triggered by the combustion process.

"For a systematic troubleshooting process, I need your help to potentially..." To be able to exclude or add points.

The following causes, in my opinion, should be considered in order of importance:
- Worn engine mounts.
- Faulty ZMS (Does the DSG-TDI have a ZMS, and are you aware of any related issues?)
- Coked or defective plasma discharge elements (shouldn't the LRR correct this - or not?).
- Software update (highly unlikely, as the lambda sensor readings are normal and the combustion is stable).

Have you experienced similar problems, or is it possible to make progress with a diagnosis here without having to replace parts immediately?
I'm not very familiar with piezo-injector elements. Is it possible to perform a diagnosis using a block injection pressure (BIP) sensor or similar, analogous to how it's done with solenoid injectors? Are there any experience-based or threshold values for GDP?

Best regards,

Andreas.

Hello Andreas,

Can you estimate the amount of play in the dual-mass flywheel (DMF) by manually rotating the engine in gear and listening (or watching) for when you start to hear or see movement in the engine?

Quote:

DSG-TDI is a type of ZMS

.
Yes.

What is the engine noise like when the vehicle is turned off?

Best regards, Rainer.

Rainer, it's good to hear from you again...

I'll do the proximity sensor test tomorrow morning and also listen carefully to the parking sound again, with the hood open. Without paying particular attention, I would say the parking sound is rather unremarkable. The engine starts smoothly, with no hesitation or knocking.

I haven't had any experience with faulty ZMS (dual-mass flywheels) yet. Are there any faulty ZMS that are acoustically unnoticeable? That would actually fit the error pattern.

...to finally wrap up a topic and also post the solution here in the forum...

The reason for the idling vibrations was clearly the engine mounts.

After replacing both engine mounts and the torque strut (~300€ including installation at VW), everything is quiet.

Even during the initial creep, which can be exciting with the DSG transmission, the load change reactions have become more pleasant and smoother.

After 4 years and 150,000 km of highway driving, I wouldn't have expected the engine mounts to be worn or defective, especially since, upon removal, there was no evidence of excessive wear on the mounts themselves.

Greetings.

Only 300 euros?

Does the engine cradle need to be removed to access the torque mounts?

Officially, he has to leave.

m;

Dieselmartin,

I can't tell you. The total was under €300, and it included all three old tires in the trunk.

Greetings.

Three parts?

Because the bearing of the rotating support is in two parts.

Here, you can see the two halves of the shell.
http://www.atp-tunershop.com/images/product_images/info_images/3041_0.jpg