ARL Issues: Troubleshooting & Solutions

Hello everyone,


I hope you can help me with this. I don't have enough experience reading log files yet.

I have a Leon TDI 4x4 with an ARL engine (110 kW). Unfortunately, I feel like it should perform much better.

Here is a log from MWB 007-011-008-009.
/viewtopic.php?t=14067

Can you see any potential sources of error here?


Sure, here's the translation:

"Thank you in advance!"

Hello,

I don't find your LD (likely "LD boost" or similar) to be that impressive, but I'm not familiar with your engine. It would certainly be interesting to log the air mass and quantity limits sometime.

Please log "003-008-011" to a file and repeatedly run the engine at full throttle from 1500 to 4000 rpm.

Then create a nice graphic from it and upload the complete XLS file.

"Then you will be helped."

m;

As a quick initial check, based on what I've seen so far, I suspect the turbocharger or the intercooler system. The target boost pressure is not being reached above 3,000 RPM.

Either there's a leak somewhere, or the EGR valve isn't closing properly. The fuel injection quantity seems normal above 2,000 RPM, but it's worth checking. Is the engine producing noticeable black smoke that's visible in the headlights of the car behind you?

Hello and thank you very much.

1. I will take more logs. Should I include an uphill section? -> More data/time interval.


2. @Roger: I can definitely detect some static noise, and a clearly audible whistling sound can also be heard when the radio is turned off.

Whistling sounds are generally normal, but should only be audible with the window open, especially during acceleration. Based on my own experience, I would recommend checking the charge air system for any signs of oil leaks. In my case (ASZ engine), the connector at the EGR inlet was so worn that it was leaking air. There was also a significant amount of fresh oil residue underneath it.

Okay, but first, let's make sure the logging is done properly; something else might turn up.
Going uphill, it's probably not bad, but a higher gear might also work.

Good evening,


Okay, I was out and about again and logged some data.
/viewtopic.php?p=97603#97603

Aufzeichnung bergauf 3. oder 4. Full throttle.

I have inserted diagrams in each case; hopefully, they are informative...

I've noticed that the light intensity (LD) systematically decreases after a certain speed.
How should the AGR values from MWB3 be interpreted?


"I also logged some data for MWB 23 while it was running at full load - is it possible to draw any conclusions from this data?"


I hope you can help me a little bit based on this data.

"I think this will be a bit more complicated. In my opinion, the 3/8/11 log looks good, with no major errors visible (on the contrary, the values are good). The boost pressure is slightly below the target, but the boost control valve could still increase the boost pressure. The mass airflow sensor (MAF) values are also completely within the normal range (which isn't always the case). In the relevant engine speed range, the soot management system is not active (it's not the controlling factor). The power loss shouldn't be that significant. Is the maximum speed being reached? When was the timing belt changed, and what is the fuel consumption? I would rule out the EGR system, as the MAF values are too good for that."
Is the latest software version installed in your vehicle (you might want to have this checked by a Seat dealer)? Otherwise, there could be a defect that isn't monitored by the MSG, or a misadjustment of the valve timing or the high-pressure pump (+ possibly worn seals). It's also possible that the catalytic converter/exhaust system is clogged or constricted. Have you checked the tandem pump to see if it's reaching the required pressure? Also, have a check performed on the pre-lift pump.

Regarding your questions:

The vehicle now has 160,000 km on the odometer. The timing belt was replaced about 10,000 km ago. Since then, I have been driving the all-wheel-drive vehicle.
Regarding performance:
Maximum speed, after a very long acceleration, was 210 km/h (indicated on the speedometer).
When accelerating, there is hardly any noticeable advantage compared to a Golf 115PD.

Software version, control time, catalytic converter, and pumps have not yet been checked.

Hello.

You're saying that the first timing belt wasn't replaced until 150,000 km? Wow, that's lucky. According to the plan, it should have been replaced at 90,000 km, or at 120,000 km for the newer models.

Sure, here is the translation of the text from German to English:

"MFG" is an abbreviation for "Mit freundlichen Grüßen," which means "Sincerely" or "Best regards" in English.

Hello.

Okay, I've looked at your logs. However, I can't see anything that seems unusual.
Today, I drove my ARL, but without all-wheel drive. In 3rd gear, from approximately 1500 RPM to 4200 RPM, it also takes about 7-8 seconds, just like yours.

That's actually always been the case with mine. I've now driven over 170,000 kilometers.
Regarding the top speed (V/max), I can only say that all-wheel drive vehicles tend to lose power at higher speeds. I previously owned a Golf 3 VR6 Syncro. It had 190 all-wheel drive horsepower, but even it didn't quite reach the top speed of a similar model without all-wheel drive. And it only had "174 horsepower. Tomorrow, I'll log the same data in 3rd gear and post it, so we can compare.

For comparison with the 115 hp PD model, I have to say that this one definitely cannot keep up. I think you can't tell the difference based on feel.
There might still be a little bit left in the first section. But in the following sections, the ARL is gone.

"Why don't you do a 0-100 km/h (0-62 mph) test with VAG-COM, just for comparison?"

Best regards, Charly.

lfuzi wrote:

Good evening, Okay, I was out and about again and logged some data. /viewtopic.php?p=97603#97603 Aufzeichnung bergauf 3. oder 4. Full throttle. I have inserted diagrams in each case; hopefully, they are informative... I've noticed that the light intensity (LD) systematically decreases after a certain speed. How should the AGR values from MWB3 be interpreted?

EDIT
Hi,

The relatively low load detection (LD) in the lower sections, combined with the somewhat overly aggressive loader control (TV), suggests to me that either the VTG rod is misaligned or the pneumatic pressure is too low.

AGR seems okay to me.

EDIT 2
Another possible cause: a bottleneck in the intake path leading to the compressor, such as a clogged air filter or something with a similar effect.

Good morning.


@zak: I've visually inspected the KAT unit - it seems to be okay.
I plan to start working on the motor control system this week - it's possible that the issue lies there.
"Dog" is buried.
Okay, the fuel consumption is 6.5 liters - I drive about 100 km of rural roads daily, at a normal speed.
Tempo.

@ulf: Regarding the "bottleneck" leading to the compressor: Luffi is quite new - I want to rule that out as a cause - otherwise, what else?
How can I inspect/adjust the VTG rod?

@charly: I'll run the 0-100 test, but I don't think we can draw any meaningful conclusions from it, right?

lfuzi wrote:

@ulf: Regarding the "bottleneck" leading to the compressor: Luffi is quite new - I want to rule that out - otherwise?

Possible obstructions: leaves, bird nests, rags, etc. in the suction nozzle; pipes between the mass flow meter and the compressor are crushed.

Quote:

How can I check/adjust the VTG rod?

-> Read technical articles on the function and configuration of VTG chargers.

I'm also inclined to rule out a blocked cat: in that case, the air mass would have to be lower (even in the higher corridors, where the LD is consistent).