Motorprobleme beim ARL Motor (1,9er mit 150PS) | Posts 16+

@ lappen.

If the excavator bucket is positioned at a steep angle, there will be little digging force (or pressure).

To achieve high pressure, they are flattened and positioned parallel to the exhaust gas flowing in from the outside (almost tangentially to the housing), forming a small opening towards the turbine. This results in a higher flow velocity and a higher turbine speed, which leads to increased boost pressure.

You can find this information in the book "Diesel Engine Management" by BOSCH.

I have it all here: https://community.dieselschrauber.org/en/viewtopic.php?t=7479&highlight=steil+flach+druck#49247
explained in detail.

Okay, please provide the German text you would like me to translate into English. I will only provide the translation.

OOPS!! Sorry, I wasn't paying attention.

That's exactly what I meant.

"That sounds reasonable. It would be a "minor" problem if it's a leak on the pressure side (unless it's the LLK itself), which I will check carefully. Additionally, I will also disable the EGR valve (using a gasket). Is the VTG inspection still required for the ARL engine as well? Doesn't that engine have a larger turbocharger?"

You can check the VTG (Variable Torque Gear) on any loader of this type using a pneumatic-mechanical adjustment system and the method described in the technical article.

That sounds reasonable. That would be another 'small' problem if it's a leak on the pressure side (unless it's the LLK itself). I will check that carefully. Additionally, I will also disable the EGR valve (using a gasket). Is the VTG inspection still required for the ARL engine? Doesn't it have a larger turbocharger?

Hello,
Well, first of all, a leak is a leak.
First, locate it.
Best regards,
Günther.

What else I've noticed is:

The highest air mass setpoint value of 850 mg/H somehow doesn't quite fit with the ARL (Air-Fuel Ratio Limit). Even with a lower boost pressure, the full load setpoint is between 900 and 1250 mg/H. However, the logged actual values are fine despite the lack of boost pressure.
Are you sure that the correct control unit with the correct mapping is installed for the ARL?

@Roger

Hmmmmmm... it depends on the engine control unit (ECU) number. We've worked on a few PD engines where it was like that, with around 850mg/H. But some others had more. I think I remember reading somewhere that it has to do with the resolution of the interface.
The problem seems to be related to the diagnostic system, but internally, the control unit is working with the correct values.

Hello again,
Okay, the weekend is over and I've tested a few things:
Wastegate valve replaced - no improvement whatsoever.
Vacuum system checked, hoses replaced - leak-free.
Turbocharger removed - visual inspection is okay, shaft play is within acceptable limits, no grinding on the housing, and no significant carbon buildup.
Oil change done (due to the turbocharger removal).
AGR shut down.
Charge air cooler checked.
Result:
"No more black smoke during partial load operation, but still significant black smoke during full load operation. The turbocharger whistles are clearly audible (especially under load)."
After a short period of operation at full load - emergency mode with error.
17964 - Charge Pressure Control: Negative Deviation.
P1556 - 35-10 - - - Intermittent.
SHIT!!!
Okay, test drive with VAG-COM:
"The target boost pressure is never reached under load (deviations of up to 0.3-0.4 bar!!). At partial load, the values are approximately halfway correct. The LLM (Low Load Mode) value is within range (up to 1249)."
I'm really dreading dealing with a turbocharger or liquid cooling system.
I'm really at a loss; do you have any other ideas? I can also provide the log if a moderator allows it.

Zak1976 wrote:

Charge air cooler checked. Result: no more soot during partial load operation, still significant soot production during full load operation, turbocharger whistles are clearly audible (especially under load). After a short period of operation at full load - emergency mode with error. 17964 - Charge Pressure Control: Negative Deviation. Bitte gib mir den deutschen Text, den du übersetzt haben möchtest. The target boost pressure is never reached under load (deviations of up to 0.3-0.4 bar!)

.
Hi,

The underlined passages still suggest a leak somewhere between the compressor and the engine.
Perhaps it's a crack in a plastic or rubber part that only opens under pressure – there have been some incredibly strange things found in the most incredible (and inaccessible!) places.

I would like to search specifically in that direction again, and pay particular attention to any suspicious oil stains.

I'm hoping to find a leak somewhere.
Unfortunately, I have no idea how to check the system for leaks. How much pressure can it withstand? Would 1.5 bar be sufficient? How can I seal the pipes or the coolant system well enough to perform a leak test? I haven't found any oil leaks. How could I check if the turbocharger is still reaching the correct pressure? I know there are many questions, but maybe you have some ideas. I would appreciate any help.
Best regards.

Zak1976 wrote:

I really hope to find a leak... Unfortunately, I have no idea how to check the system for leaks.

Disconnect the hose from the compressor outlet and somehow seal it to make it pressure-tight.
Detach the hose from the GRA unit and plug it as well. However, install a bicycle valve or similar fitting into that plug, and then inflate everything.

Quote:

How much pressure can it withstand? Will 1.5 bar be enough?

If the pressure loss is caused by a leak, it should open significantly below 1.5 bar .

Quote:

How could I check if the turbo is still reaching the target pressure?

By ensuring a guaranteed dense charge air path and then logging it again, or by installing a (more reliable, due to its simplicity) LDA directly.

P.S.:
You don't see a Golf 3 converted to electric drive around every corner.
If you have clear documentation about the problems and solutions associated with it, the IMO would be interesting to many people here.

Hello,
If you hear a loud hissing sound while driving, you should be able to pinpoint the source of the hiss by revving the engine when the car is stationary.
Best regards,
Günther.

@Ulf:
Okay, I'll try. There has to be something out there. Yes, I'm also proud of the conversion; it's a lot of fun (when it works). I don't have a documentation in that sense, but I could create one and publish it here. It was definitely a lot of work, especially because VW isn't very helpful, and it was difficult to get access to certain technical documents. Technically, it wasn't as difficult as expected (aside from the electrical components). The engine and the 6-speed transmission fit well (although I still had to modify the engine mount because the oil pan would be too close to the ground otherwise), but the result is worth it. It's very interesting to see the expressions on the faces of 330d drivers when they get overtaken by a Golf TDI...

@Gustav:
The engine is very loud with the hood open (and a second one revving), making it difficult to pinpoint the source of the noise. I think Ulf's approach is excellent, and perhaps there are other possibilities (like lubricating with soapy water or using starting spray...), as I said, any tip would be appreciated.

Zak1976 wrote:

The engine is very loud when the hood is open (and a second one revs), you hear a lot of noise, and it's almost impossible to pinpoint the location.

Hmm, have you ever (with the engine warmed up, of course!) given it full throttle to around 4500 rpm?

During the AU test, the boost pressure briefly increases to approximately the full load value in the high rpm range . The sound of air escaping from a leak should then be audible, even with the hood open (or even closed), according to my opinion .

When applying the gas "gently," the pressure barely exceeds 0.2 bar, and at that point, you can't usually hear most of the leaks whistling/hissing -> LDA rulez .

I've moved the IMO topic, which I find quite interesting, to the professional section.