Luftmasse zu hoch A6 4F 3.0 TDI ASB | Posts 16+

30-10-2018, 9:07 Subject:

dieselschrauber wrote:

Hi,

Quote:

In addition to the fact that the injection timing is quite late. Since this is a consequence

How do you come up with it?

I'm not sure what you mean. Have I logged, with VCDS

dieselschrauber wrote:

The injection timing is essentially dependent on the coolant temperature. Check the in the engine control unit's measurement values for plausibility.
Would also explain the increased consumption.

I have already had the idea. The temperatures are plausible. Over the weekend in cold weather, the KM temperature on two measured days in the morning before starting was 2-3 degrees above the KS temperature and 2-7 degrees higher than the oil temperature.

In the operation, all explanations are plausible.

I'm running out of ideas...

30-10-2018, 23:00 Subject:

Hi,

so, the coolant temperature in the system is 90-100°C?

Please also share the log with the injection timing data.

Best regards, Rainer

31-10-2018, 0:12 Subject:

dieselschrauber wrote:

Hi,

so, the coolant temperature in the system is 90-100°C?

Please also share the log with the injection timing data.

Best regards, Rainer

Took a little while, but reached 92°C on Sunday in the frosty temperatures.

Logs are at home, I will be in Graz until tomorrow evening.

Maybe I'll be able to make it on Thursday.

Best regards,

Bo

01-11-2018, 11:05 Subject:

Ste.Bo wrote:

Took a little while, but reached 92°C on Sunday in the freezing temperatures.

Unfortunately, it also looks good. I'm curious to see what the injection timing points are in the log. At higher speeds and under heavier loads, the injection start time needs to be advanced, possibly indicating a fault in the VCDS system?

Best regards, Rainer

03-11-2018, 18:10 Subject:

Hello everyone,

On the holiday, the BPP from the family was back home, so I started playing with him.

Right from the start: the excessive air mass is gone. After I had replaced the solenoid valve, the error had moved to the other car. It seems that dirt had been sucked in when the original pressure sensor failed. Interestingly, the valve diagnosis was always OK.

Because the 87-92°C KM temperature seemed a little too low to me, I also installed a new KM sensor. The values have remained the same.

Intake length measured with BGS plugs. No leaks found.

I have now exchanged my car with my wife and drove to work yesterday and today (100km on a federal highway) using it. Before the problems, I used between 7 and 8 liters depending on traffic and weather conditions. Now 11.2!
[EDIT: After recalculating with the gas station and a calculator, the car always shows 0.2-0.3 liters more /EDIT]

On the highway, above 140 km/h, the fuel consumption is normal. In the city and on country roads, it consumes a lot of fuel. According to the display, I need 8.5 liters/100 km at both 120 km/h and 160 km/h on a straight road with cruise control. The absolute value is irrelevant here, but it drives me crazy that the consumption between 1500 and 2500 U/min is almost 50% higher than usual, and I can't find the cause.

I logged a portion of the return trip today. Intentionally including the section with multiple town passages, as all target/actual values are within acceptable ranges when traveling at a constant speed of 100 km/h on an open road with a consistent load.
For insights, I am grateful.

Okay, yes, I've also attached screenshots of the nozzles, because that question comes up all the time.

Greetings

Bo

03-11-2018, 18:16 Subject:

dieselschrauber wrote:

It took a little while, but it reached 92°C in the freezing temperatures on Sunday.

Ste.Bo wrote:

Unfortunately, it also looks good. I'm curious to see what the injection timing points are in the log. At higher speeds and under heavier loads, the injection start time needs to be advanced, possibly indicating a fault in the VCDS system?

Best regards, Rainer

I haven't had the opportunity to log high-load data with the correct air mass. I'm heading north tomorrow, so I'll be logging on the A7.

Greetings

Bo

05-11-2018, 21:33 Subject:

Hello Bo,

The injection nozzles at the calibration points only indicate something about the functionality of the injectors, but nothing about the injection timing. Background information:
/viewtopic.php?t=26829

There are almost certainly several injection timings that are relevant, but only the start of the main injection is important.

What does fuel temperature do? Simple things like the fuel filter have been checked/replaced (leading to insufficient fuel supply).

Best regards, Rainer

05-11-2018, 21:39 Subject:

dieselschrauber wrote:

Hello Bo,

The injection nozzles at the calibration points only indicate something about the functionality of the injectors, but nothing about the injection timing. Background information:
/viewtopic.php?t=26829

There are almost certainly several injection timings that are relevant, but only the start of the main injection is important.

What does fuel temperature do? Simple things like the fuel filter have been checked/replaced (leading to insufficient fuel supply).

Best regards, Rainer

KS-filter and KM-temperature sensor two days before the last attached log. KS-temperature sensor replaced due to a faulty BPP. I have logged the start of the main injection.

Greetings

Bo

05-11-2018, 21:46 Subject:

Hi,

I just found the injection start time in the log, and it also looks okay. The back pressure on the DPF seems to be within the acceptable range. I'm starting to run out of ideas.

Slipping brake, car rolls easily?

Best regards, Rainer

05-11-2018, 21:47 Subject:

dieselschrauber wrote:

Hi,

I just found the injection start time in the log, and it also looks okay. The back pressure on the DPF seems to be within the acceptable range. I'm starting to run out of ideas.

Slipping brake, car rolls easily?

Best regards, Rainer

Welcome to the club

Yes, the car is rolling far, far away. Wheels are cold.

05-11-2018, 21:50 Subject:

Does the engine perhaps try to regenerate indefinitely? Does the mileage since the regeneration show, and is it in DPF regeneration mode?

The exhaust temperatures in your log are too low (normal), perhaps the system hasn't been regenerating properly during logging...

Best regards, Rainer

06-11-2018, 12:48 Subject:

dieselschrauber wrote:

Is the engine possibly trying to regenerate indefinitely? Does the mileage since the regeneration show, and is it in DPF regeneration mode?

The exhaust temperatures in your log are too low (normal), perhaps the system hasn't been regenerating properly during logging...

Best regards, Rainer

Hello Rainer,

I've been closely monitoring the DPF since the cleaning in the summer. It regenerates very rarely. At the time of the last log, it had been 800km since the last entry, and there had been no attempts or failures.

Regarding the exhaust temperatures... I also found them to be very low while driving, but during the last forced regeneration (a few weeks ago as part of the troubleshooting), the temperatures before the cat/before the DPF reached 684.4°C/631.3°C. I believe this is plausible. Furthermore, I observe a meaningful and graded temperature difference between ATL, DOC, and DPF, even though the actual levels are relatively low in everyday use.

I'm going to leave it like this for a couple of weeks. I'll be away on business until the 20th. After that, I will review the entire text more carefully.

Thank you for your consideration and best regards.

Bo

07-11-2018, 20:31 Subject:

Possibly, the AGR valve is malfunctioning intermittently, or the corresponding solenoid valve? The RPM range with high fuel consumption would fit, as it's where the engine works the hardest...

Is the ventilation of the underpressure system free?

Best regards, Rainer

dieselschrauber · 12-11-2018, 22:44 Subject:

I think I've got it. I looked at a whole bag of logs from the past few weeks over the weekend. I've also noticed that, except for very long stretches on the highway, I've never had a transmission oil temperature above 60°C.

Subsequently, I checked a log where I could see the transmission status. And indeed, when driving on a 100km federal highway, I reached a maximum of 51°C, and the TT (Transmission Temperature) did not exit the warming mode. A mistake will not be dismissed.

Does anyone know if it's possible to access the sensor without having to open the gearbox? Or is it embedded in the mechatronic module? I will be able to see it after the next weekend.

Greetings

Bo

dieselschrauber · 14-11-2018, 21:02 Subject:

Ste.Bo wrote:

Does anyone know if it's possible to access the sensor without having to open the gearbox? Or is it embedded in the mechatronic module? I will be able to see it after the next weekend.

Greetings

Bo

The temperature sensor is firmly mounted on the control unit board.
The transmission control unit for the 6HP19A is located inside the transmission.
It is a permanently encapsulated PCB that is mounted above the mechatronic components and attached to them. It is therefore always immersed in the oil bath of the oil pan. Simply removing it is not possible, or Replace, as the WFS is VIN-bound.
Unfortunately, this means that the G93 bulb cannot be replaced individually, and it is also not available for individual purchase.

Since the automatic transmission's temperature control in the A6 4F is regulated by the engine's coolant control via the coolant, I would recommend checking the engine temperature. The ATF oil cooler is integrated into the water cooler on the driver's side. My automatic transmission also behaves differently since a new thermostat was installed. Consumption has also decreased.

Greetings, Mpire

15-11-2018, 12:22 Subject:

Mpire wrote:

The temperature sensor is firmly mounted on the control unit board.
The transmission control unit for the 6HP19A is located inside the transmission.
It is a fixed-mounted PCB that is mounted above the mechatronic components and is always immersed in the oil bath of the oil pan. It cannot be simply removed or replaced, as the WFS (Webasto Fuel System) is VIN-specific.
Unfortunately, this means that the G93 bulb cannot be replaced individually, and it is also not available for individual purchase.

Since the automatic transmission's temperature control in the A6 4F is regulated by the engine's coolant control via the coolant, I would recommend checking the engine temperature. The ATF oil cooler is integrated into the water cooler on the driver's side. My automatic transmission also behaves differently since a new thermostat was installed. Consumption has also decreased.

Greetings, Mpire

Hello Mpire,

Thank you for the information. I exchanged the thermostat with the one from the BPP. It didn't make any difference. However, since the one I had was also around 180,000 km, I will probably try with a new one. Although I hesitated because the opening at 87°C was visible in the temperature profile.

Greetings

Bo