Nach ESD Tausch drückt Diesel aus der Rücklaufleitung (AEL) | Posts 16+

Hey Rüdi,
That's the same issue I'm having with the hollow bolt on my old A6.
Feel free to take a look at the first photo at the beginning of this thread.
You can tell it's that old screw.
(I'll probably take it apart soon...)

Before that, however, I will continue searching for my second one. Looking for a set screw...

However, the check valve in the last oil drain line (to the MSW) will definitely be installed.

Should I take the second one? Can't find the set screw, so I'll get a new one.

DIY solutions are okay to a certain extent, but nothing beats the original.

Hi,
The oil drain line is essentially the same for all fuel injectors; they can be connected to each other in any configuration, as long as they are all connected and have a line leading to the return flow.
If absolutely nothing comes out after swapping the ESDs, then at least one of the ESDs is likely faulty, starting with the one immediately before the return line connecting to the T-connector on the main sewage water line.
The cables with textile sheathing are perfectly adequate for the return line.
You can still check the continuity of each individual ESD by blowing into it and verifying the connection between the leak oil ports.
I would completely revert to the original ESDs, check the return process, and then install the new ESDs one by one. They are all suspicious.
hg
Herbert.

I was just looking at one of my air-filled nitrogen (AFN) tanks. It seems to have valves inside that maintain a specific internal pressure, if I understand correctly.

The internal pressure may be higher due to the new nozzles, and now that's too much for the valve, where the spring may have become fatigued.


According to 7zap, that is the part number for the hollow screw with regulating valve.

068130157

@ Herbert

Sure, you can run the oil return lines in any direction you like. It's just the return flow...

But what you wrote about there being a problem with the refurbished nozzles is ultimately my opinion as well, which is why I started the thread in the first place.
It used to work before.
I just thought that Bieberach would be more reliable in this case...
The people from Bieberach wanted to call me today (I even have it in writing), which, of course, did not happen .

The vacation is just around the corner... You can sometimes afford to lose a customer.
But there are reviews,

I will do it the way you suggested.
First, test the leak-tightness of the connector connections...
Otherwise, revert all nozzles to their original settings and then replace them one by one. Luckily, I still have a complete set of [something] lying around...

More information will follow, but it may take a few days.
There are also still normal, everyday things to take care of .

@Ruedi
Thank you for taking the time to double-check!
That's really kind of you.

Yes, as Richard wrote and as you have determined, the same is true for me.
The screw is attached to this valve.

I will continue to follow this, but I also need to take care of other things now, otherwise my wife will eventually be unhappy .

We will respond to all of you by the end of next week at the latest, hopefully sooner.

Thank you very much to each and every one of you, and see you next week.
Wool.

Quote:

The internal pressure may be higher due to the new nozzles, and now this is too much for the valve, where the spring may be fatigued.

It may be the case that the new nozzles have a slightly higher opening pressure. However, the amount of fuel that is returned from the high-pressure part of the pump to the low-pressure part through the control orifice is relatively small, so it cannot significantly increase the pressure.
hg
Herbert.

Hi.

In my opinion, the only way for a leak to occur in the oil feed lines, assuming the injectors are only dripping from the lines, is a blockage of the fuel return from the ESP to the DiFi.
From the blind plug on the last distribution header (remove the blind plug) to the hose that connects to the ESP return line, it should be possible to blow through it easily with your mouth, without significant resistance.

It's probably not the DHK (Diesel High-Pressure Common Rail), because either they would be running wild in reverse, which the questioner says they aren't, or the pressure in the fuel return line, where the leak-off pipe is connected, is simply too high.

The person asking the question should just take a picture of the DiFi (presumably a type of device) and the hose connection.

Best regards, Rainer.

Good morning, everyone.

@Rainer

Thank you for the comprehensive answer.
Here's a picture where the swelling is somewhat visible.
The transparent hose connecting the last DHK unit to the MSW is only installed for testing purposes. Normally, a standard hose is available there.

All the DHKs are fully operational; I tested them again yesterday after Herbert's suggestion.
I just performed a counter-test, and instead of using a plug, I connected a return hose to the number 1 port. DHK is inserted.
There, diesel fuel also emerges and is pushed from the MSW (presumably a machine or system) towards the DHK (likely another machine or system). Therefore, the connectivity is ensured.

And this morning, I crossed the "Knackfrosch" again, but after taking a picture.
Background: I was trying to test the permeability towards the tank by gently blowing air through the "Knackfrosch" (a specific component) with low air pressure. Sometimes air would pass through, albeit with some back pressure, and sometimes nothing would pass at all. So, I also carefully blew air through the line leading to the tank. It went smoothly as well.

Since I bypassed the fuel filter again today and blew out the line to the tank, there has been no more diesel leakage.
Around noon tomorrow, I'll be getting a new "Knackfrosch" (likely a toy or gadget), and then I'll test it again.
More information to follow.

Just a quick note about the photo:
I had to extend the cable from the MSW to the Knackfrosch, which is why there are three cable clamps. The route is definitely clear and passable all the way.

What makes me suspicious about the whole situation is that the problem arose with the exchange of the digital key handle. "I'm leaving everything else untouched except for the return hoses connected to the heat pump, and this problem definitely wasn't there before. I'm sure it wasn't unnoticed either, because it was too obvious."

Somehow, dirt or crumbs got into the return line - it's blocking the inflow in the "Knackfrosch" .
hg
Herbert.

On the VP37 pumps that I am familiar with, there is always a threaded fitting with a flow restriction installed on the return line. It has to be that way, because otherwise, the internal wing cell pump (is that the correct term?) which also draws in diesel, cannot build up any internal pump pressure.

Hello everyone,

So... Now I have replaced the "Knackfrosch" again.
Now, it can be seen through the transparent hose that the diesel is no longer being forced towards the DHK (presumably a specific component), and everything is now sealed.
A test using the standard return hose instead of the transparent hose was also successful.
So, the other frog must actually be a bit strange.
Even when fully expanded, it's only occasionally passable, and even then, it's not clear.
I wouldn't rule out dirt in the line causing the problem, but whenever I work on the fuel system, I make sure to cover any exposed connections. But you should never say never...

Due to its age, I will replace the hollow screw and, as a preventative measure, install a check valve in the line between the last DHW (domestic hot water) tank and the MSW (manifold system).

I'm sorry if I've bothered you with this topic.
Due to my personal circumstances, I rarely work on the car anymore, and after the DHK replacement, I followed a false lead.

Thank you all very much! It certainly helped in some way .


Okay, I'm going to investigate why I always have a lot of air in the supply line to the MSW (Multi-Stage Water softener) in the mornings, and as a result, it always takes almost 5 seconds to get it running.
But that is a different topic .

Also, here's the translation:

"Also, please also install a check valve in the supply line."

Hey Rüdi,
(Name edited.) Sorry, Rüdi.

I already did that a while ago, when I was trying to find the air in the supply line.
I feel like I've checked everything.
Furthermore, I plan to install transparent hoses in the main lines, essentially as viewing windows. Let's see where the air bubbles first appear.
The fittings are tight, I also had the fuel tank cap loose before, the fuel pump is new, and the "Knackfrosch" (presumably a specific part) is new again...

The car was in a garage until August 2022, for 6.5 years, and the morning starting problem had been present for a longer period before that.
I remember it happening almost suddenly.

Since the car is often parked for...two weeks, I can continue searching without feeling rushed.
Let's see what happens.

Best regards,
Wool.