Valve Cover Gasket: Reviews & Sealing Tips (ASZ)

Hello everyone.

Question:

I would like to replace the harness/cable bundle for the power distribution units (PDUs) in my ASZ (Automotive Service Unit).

I'm wondering how I'm going to get the valve cover sealed.
The search function didn't exactly make me any smarter either.

A representative from Bosch told me that the old valve cover wouldn't seal properly anymore, and that I should get a new one, which would cost over €100.
It's just too much for me.

I'd like to briefly summarize your opinions on this topic.

The man is right. Put a new lid on it, and you'll be fine.
2. The man is crazy; just add some new lyrics and it's good.
3. The guy is completely crazy, just clean it up, apply some sealant, put the old lid back on, and that's it.

Which type of sealant would you recommend, and is it suitable for the problematic corners of the lid?

Thank you in advance for your help!

Best regards,
Jörg

Seals are available individually. However, normally they will seal again after disassembly, if they were okay beforehand.

If the sealant is still pliable and not completely hardened, it will soften again. Just add a little more sealant to the four corners of the bearing covers, and it will fit properly.

Thank you.
"By the way, I forgot to mention that the engine has been intermittently misfiring for a few days now, and quite often, and then it stops accelerating. I used to experience this very rarely, and only when it was very wet."
When I press the clutch, the engine sometimes returns to its normal idle speed, but sometimes it stalls.
As an error entry, I only have an implausible signal plus a missing signal from the crankshaft sensor.
I'm now wondering, if the wiring harness has a defect, wouldn't that mean the error originates from the PDEs?
So far, I have:
The values of the air-fuel ratio sensor (AFR) at idle were checked for plausibility => everything is okay.
Relay 109 replaced => no change.
Tomorrow, the camshaft sensor will be replaced, and the timing belt will also be replaced as part of routine maintenance.

Best regards,
Jörg

If the NW sensor fails, the engine remains running (likely in limp mode with no power) and (hard to start). The KW sensor is used as a replacement. If the KW sensor fails, the engine will stop.
Changing things up is a good idea.

There must be an error if the control unit is not detecting the kilowatt signal.
Correct?
I'm also not sure about the connector strip for the pressure sensors (PDEs), because it seems like they all fail together. I keep reading about individual PDEs failing, causing rough engine running ("like a tractor") and error messages related to the connector strip.


Best regards,
Jörg

Light in the darkness.

The valve cover will stay on for now.

Der Motorkabelbaum soll defekt sein, lt. Bosch Service.
He should be there by mid-next week.
I will exchange it when I have time and let you know.

Best regards,
Jörg

Hi,
Check first yourself where the error is coming from.
Several things could be relevant in that case.
- the NW sensor itself;
- Connectors;
- Parts of the wiring.
You can actually do quite a bit yourself.
The PDE wiring harness has nothing to do with the ZK.
Replacing the wiring harness based on suspicion, without checking beforehand, costs money, might be wrong, and is actually against the principles of good diesel mechanics.
hg
Herbert.

Herbert wrote:

Hi, Check first yourself where the error is coming from. Several things could be relevant in that case. - the NW sensor itself; - Connectors; - Parts of the wiring. You can actually do quite a bit yourself. The PDE wiring harness has nothing to do with the ZK. Replacing the wiring harness based on suspicion, without checking beforehand, costs money, might be wrong, and is actually against the principles of good diesel mechanics. hg Herbert

Hi Herbert,
The camshaft sensor was replaced yesterday, but the error related to it reappears immediately after being cleared. You can also notice it when starting the engine.

I've checked the connectors before, so I'll start by checking them again.

I even put the control unit in the oven once because I suspected there might be moisture inside.

I'll leave the PDE cable strip in for now. I already mentioned that in my previous post.

Checking the engine wiring harness became almost unavoidable because the signal from the knock sensor wasn't reaching the control unit.

Two weeks ago, I bought the book "Dieseldiagnose" from the Vogelbuch publishing house.
(This is a bit old, but still very interesting.) There, I read about diagnostic options, such as using a Y-adapter and a socket tester.
Given that the jerking was accompanied by a complete refusal to accept the accelerator pedal, and since the Seat has Bosch throttle bodies and a Bosch control unit, it seemed logical to contact Bosch service for assistance.
Fiddling with probes in the small contact points of the engine control unit and potentially causing further damage or instability there, I didn't think was the best idea either.
Debugging sporadic errors is a real pain; when you're actively trying to find them, they never seem to occur.

Ultimately, I had also read in used car reviews that the wiring harnesses of the Skoda Fabia, a sister model, were prone to letting in moisture but reluctant to let it out, which could lead to malfunctions.

The engine wiring harness costs €160 and has already been ordered. I hope that it can be replaced without major difficulties. If everything then works again, I will wonder why I didn't do it much earlier. The pressure to fix it wasn't there yet, and if I may answer the question myself .
Due to the moisture problems alone, I will also refrain from repairing the engine wiring harness. I'm sure a new one will be fine.

Regarding diesel engine repair, I must admit that I prefer to deal with the problems theoretically in order to keep workshop costs as low as possible.
It has always worked excellently with the help of this forum.
Sure, I'll help out with the assembly if it fits my schedule.

Okay, now hit me .

Best regards,
Jörg

No, why?
hg
Herbert.

To get back to the VDD:
"So far, it has always been the same as described by others for all 1.9 engines: it always leaked. The only exception was my own Passat. When I replaced the PD elements at 190,000 km, the cover simply wouldn't seal again. It didn't seal with the new gasket from Reinz, and it didn't seal even when glued. Because I had to remove the cover several more times for this reason, I ended up overtightening one of the screws."
Ultimately, I repaired it using a Helicoil insert, and I bought a new cover, gasket, screws, and oil cap from VW. It cost 97.xx euros. It's been installed for almost 100,000 km and it's very dry. I haven't had any problems with it since.
There are cases where the statement made by the Bosch employee is actually accurate.

Thank you for the feedback.
Conclusion:
Start with the cheapest solution, and if necessary, proceed with the next cheapest solution .

My feedback regarding my issue:

It was indeed the engine wiring harness (the smaller connector from the engine control unit to the sensors and actuators). Although only the outer sheath, i.e., the protective tubing, was damaged and no insulation appeared to be visibly compromised, my problems seem to be gone. I'm quite optimistic about this now.
It now starts up immediately again, and I haven't noticed any more jerks or interruptions.

Surprisingly, the removal process was much more difficult than the installation. I didn't want to break anything during the removal. You never know if you might need something later. In retrospect, cutting it out would probably have been faster.
"And on top of that, I also have the two 'joke' cables here; it's no surprise they're breaking, they've been repaired for the field winding of the alternator."
Now I can also start the car without needing a gas surge to activate the alternator.

Best regards,
Jörg