Problem with clutch/starter motor, Golf 4 TDI

Hello Community,

I have a problem, and I really need help.

Regarding the vehicle: A Volkswagen Golf 4 Variant TDI with front-wheel drive, GT Sport trim, first registered in 10/2003, model year 2004, engine code ASZ, gearbox code FMH (6-speed manual), currently with 430,000 kilometers, technically completely original/standard.

Regarding the issue:

At approximately 400,000 kilometers, a new clutch was installed due to wear (a complete kit from Sachs, including the dual-mass flywheel, friction disc, pressure plate, and central release bearing). Result: Everything is working.

At approximately 410,000 km, there were starting problems. The starter motor would turn briefly, then stop. It would only start properly after holding the key in the "start" position for a longer period. A new battery was installed, but there was no improvement. A rebuilt starter motor was installed, which resolved the problem for two days. After two days, noises appeared, as if two gears were slipping past each other and only making minimal contact. The starter motor spun quickly, but did not turn the engine. The starter motor was removed, and it was discovered that the ring gear on the dual-mass flywheel (DMF) was damaged (7 teeth were broken). An original VW Valeo starter motor was obtained from a salvage yard. This starter motor has a 2mm larger pinion gear and one more tooth on the pinion gear than the "rebuilt" starter motor. A new DMF from Sachs was installed, along with the aforementioned Valeo starter motor. New mass cable installed between the motor and the chassis. Everything is working, and the starting problems are only occurring sporadically now.

At 430,000 km, the clutch is not disengaging. Gear changes are only possible with the engine stopped. After what felt like 100 attempts to start the engine, everything suddenly went back to normal. One day later, the clutch was not disengaging again. The transmission was removed. The toothed ring on the dual-mass flywheel (DMF) was damaged again (one tooth broken off). The broken tooth was found in the pressure accumulator. Most likely, a tooth on the gear blocked the feathers, preventing the clutch from disengaging.
The starter ring gear is intact. On the toothed ring of the dual-mass flywheel (DMF), it can be observed that the pinion gear is not fully engaged/disengaged.
The gearbox input shaft has approximately 3/10 mm of axial play. The large bearing on the other side of the gearbox had approximately 1.5 mm of axial play, which has now been compensated for using original VW shims.

What's the problem? Is it the starter motor? Is it the clutch? Not enough power to the starter?

Thank you in advance for your help.

Joachim.

Hello!

The front end of the starter shaft is often mounted in a bore within the engine block in many vehicles.
With a brass bushing.

If that component is missing or defective, I could imagine encountering such problems.

Hello Steffen,

Thank you for the quick response. If I remember correctly, my model doesn't have that sleeve. The front end of the starter motor ends with the pinion gear.
I'm really at a loss and will ask my mechanic tomorrow if he's already aware of similar problems.

The starter motor in the Golf IV no longer has a bushing; it is free-floating.

What are the part numbers for the Valeo starter motor and the dual-mass flywheel (DMF)?

How many teeth does it have?

These are likely the variations available for your car:

https://www.rexbo.de/search?q=0+001+125+048

Hello Ruedi,

I won't be able to work on the car again until in 2 days. I will post the part numbers here.
This morning, I went to the doctor. Even the experienced doctor there couldn't offer any advice. He pointed out several potential sources of error to me, but I can rule them all out.
I suspect there's a problem with the starter motor's power supply. Could the problem possibly be with the ignition switch, the relay, or the wiring?
However, the question remains: why would an underpowered starter motor damage the dual-mass flywheel (DMF)?
He didn't chase after her.
The components have been operating for approximately 20,000 kilometers, with occasional starting problems.
that the starter motor is not spinning quickly enough. When the initial engine speed is too low, the dual-mass flywheel (DMF) will naturally rattle.

Good morning.

This morning, I was at the car and found the following numbers on the installed parts.
read out; read off; taken; noted; registered; recorded.

ZMS: printed: Sachs 2294 003 341 06T 16L 1/1
embedded: 669700
Valeo starter motor: 02M 911 023 C

There are other numbers on the starter motor, but they are not completely legible: xx 0194 SG N (the 'x' is unreadable).
and : 07RS50

Just to reiterate, I want to mention that these parts have been working for approximately 15,000 kilometers.
Unfortunately, I haven't made any progress in identifying the cause of the broken teeth on the clutch master cylinder (CMC), and I would be grateful for any suggestions or insights.
After several phone calls with the technical support hotlines of Sachs and Valeo, I now believe that an electrical problem is the most likely cause. Despite the high mileage, I can rule out all other possible causes, ranging from improper installation to damaged bearings or warped parts.
Thank you again for all possible help.

Best regards, Joachim.