Polo 9N3 (1,4l TDI PD) springt schlecht an, nach Standzeit | Posts 64+

Hi Stolli!

"Do not touch the adjustment screws of the PDEs!!!"
Alternately loosen and remove the hinge shaft until it is free. The pivot pins are now exposed.

After removing the components, mark the PDEs so you know which one went where.

Best regards from Munich!

DieselBär30x wrote:

Hi Stolli! "Do not touch the adjustment screws of the PDEs!!!" Alternately loosen and remove the hinge shaft until it is free. The pivot pins are now exposed. After removing the components, mark the PDEs so you know which one went where. Best regards from Munich!

Hello DieselBear,

Thank you for writing back to me so quickly!

But should I replace the adjustment screws?
According to Volkswagen, the following steps should be taken:

Rotate the crankshaft until the camshaft lobes of the injector pump unit to be removed or installed are pointing straight upwards.
2. Loosen the lock nuts of the adjustment screws -1- and unscrew the adjustment screws.
3. Loosen the mounting screws -2- for the swingarm pivot shaft from the outside to the inside, and then remove the swingarm pivot shaft.

Isn't there anything wrong with proceeding like that, right?
And do you loosen the camshaft while the VVT (Variable Valve Timing) components are still under load? Or does the camshaft need to be in a specific position?

Hi Stolli!

I would leave the screws in for now; that way, the set measurement will remain unchanged.

Otherwise, adjust the NW (presumably a device or setting) in such a way that the relevant PDEs (likely pressure drop elements) are relieved as much as possible, gradually reduce the settings evenly, and that's it.

Best regards from Munich!

Probably, the nuts should be loosened beforehand because otherwise, you won't be able to apply enough force to remove the pivot shaft once it's been partially disengaged.

Hmm, then I would have to adjust the NW in such a way that ALL PDEs are evenly relieved, or something like that?

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Hmm, then I would have to adjust the NW (Northwest) in such a way that ALL PDEs (Pressure Drop Elements) are evenly relieved, or something like that?

It's not possible to do that. If you are installing new adjustment screws, only turn them in as far as necessary to ensure that the pressure diaphragms (PDs) are not being stressed beyond their limit. Then, proceed with the adjustments.

I have the driver's license exam done!

Luckily, I had bought an inexpensive removal tool; one of them just wouldn't come out!
The seals don't look bad to me.

However, the PDEs show signs of wear and tear. Are these concerning?
And two lobes show slight signs of wear - should I be concerned about that?

Best regards,

Quote:

The seals don't look bad to me.

Quote:

And two cams show slight signs of wear - should I be concerned about that?

Perhaps. Take a look at the valve tappets. I think at least the hydraulic lifters in the middle are worn out. I would replace those before the bottom of the valve stem gets damaged.

Hello everyone!

@Stolli: What do the seats of the PDE look like on the ZK (executive committee)? Are they noticeably integrated or textured?

Best regards from Munich!

Hello everyone!

The seats of the PDE have slightly noticeable ridges that can be felt with a fingernail – perhaps visible in the photo on the right side.

And regarding the hydraulic lifters and camshaft: I have also attached photos here.
Approximately 100,000 kilometers ago, the Polo experienced a similar type of damage. However, in that case, it was actually a hydraulic lifter that had failed and developed a hole.

The current damage pattern to the camshaft / lifters doesn't seem severe to me. Therefore, I will probably replace the PDE seals and reinstall the PDE. And then I will wait to see if a lifter fails within the next 400,000 km.

Here's another question about the sealing set: There's a very small black O-ring included. Do I need that one?

Hi Stolli!

stolley wrote:

... fails after only 400,000 km. ...

Um, I'll have to go back and check that again... 279,000 km, okay.

My tip: Carefully sand down any sharp edges on the mounting surfaces of the ZK's (main bearings) as finely as possible (using 1000 grit!), verschandeln them meticulously (!!!), and when applying new sealant to the PDE's, apply it in streaks rather than a continuous layer. Lubricate everything thoroughly with motor oil before and after installation. Gently but firmly insert the bearing until it seats properly! (ASLE specifies dimensions for alignment!).
...and no, this is not tech porn for beginners...

I hope the new sealing system will fix the starting problem, but it will certainly be the end of the line for this particular unit – considering its mileage and, not least, the fact that the PDE injectors have already been integrated into the engine control unit.

Best regards from Munich!

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However, there was actually a hydraulic lifter that had worn out and had a hole in it.

You should take a closer look at the lifters on the camshaft; if the surface is no longer smooth... replace them before another one fails. It's obvious that the water pump is already defective. It's only a matter of time before it breaks down completely.

Thank you for your tips!

I'm still thinking about the sanding on the cylinder head...

By the way, it's now 296,000 km!

And what about the small, black sealing ring? Is that one left over?

Hi Stolli!

Stick your head inside a public toilet and take a look around.
That's where it normally goes.

Best regards from Munich!

DieselBär30x wrote:

Hi Stolli! Stick your head inside a public toilet and take a look around. That's where it normally goes. Best regards from Munich!

Ah, great!

Thank you very much!