Mehrverbrauch nach Zahnriemenwechsel 1.9TDI AVF | Posts 16+

Hi,

{DPF} may have been retrofitted, which is now clogged. Occasionally, exhaust pipes also corrode and the internal components shift, leading to a significant increase in flow resistance. The exhaust often rattles as a result.

Clearly noticeable compared to similar vehicles, low air mass values at full throttle and high engine speeds.

"Load demand/actual with 100-4000rpm full throttle log in 3rd gear should also be checked. There are countless postings on this topic." Keyword: Leak in the air intake path.

Best regards, Rainer

Thank you for the response.
DPF has not been retrofitted, as far as I know (I haven't seen anything of the sort either). The exhaust is not rattling. And interestingly, it started exactly after the ZR change, and is much more noticeable in the city than on the highway... Air mass is also slightly above the target value, and the AGR is too high. (LL 400-450mg/stroke, full load 1250mg/stroke)
Log of the boost pressure can be created on the weekend, on the highway it regulates the boost pressure cleanly, which is always perfect, even at full throttle. The boost pressure at full throttle is approximately 2600 mbar absolute. The only thing that relates to the intake air duct is that when removing the intake air hose, the hose was firmly attached to the pipe. When removing it, pieces were torn off and remained attached to the pipe. Therefore, I cut approximately 2 cm off the intake air hose, cleaned the pipe, and then properly mounted the hose. "It definitely seems to be sealing properly; you can't hear anything, and the pressure is also being well maintained."

I'm constantly wondering why the oil is getting warmer. Does the engine have to work harder (which also explains the higher fuel consumption), is it due to the different water pump (I can hardly believe it), or does the NOx (NOx) control system have such a significant impact on the engine temperature (previously set to 3 degrees late)?

Best regards, Tobias

Quote:

(3 degrees earlier)

= Requires action. The direction is really late, meaning negative NW offset?
When the negative synchronization angle is present, the NW (North-West) component of the KW (wave function) increases. Let's just assume, logically speaking.

If not, you might have found the cause.

This was before the ZR change. VCDS showed +3 degrees, which means the target value is 3 degrees too late. Immediately after the change, VCDS showed 1°, then I corrected it to 0°.

tobias_ wrote:

This was before the ZR change. VCDS showed +3 degrees, which means the target value is 3 degrees too late. Immediately after the change, VCDS showed 1°, then I corrected it to 0°.

Personal opinion, therefore I would check the direction...

So, VCDS zeigt mir, wo ich hin muss. Also bedeutet 3 Grad im VCDS, dass die Nockenwelle 3 Grad nach der Kurbelwelle läuft. This also matches the markings of my predecessor, which no longer fit properly after I turned the camshaft clockwise to 0 degrees.

Today, I drove about 200km on the highway, and the fuel consumption was only slightly higher than usual (according to the BC). The oil temperature was only 5-10 degrees higher than before.

I also disassembled the car again and checked the timing. As expected, it was exactly correct. Now I can rule this out, but I still can't get further with the problem. The roles and the water pump all feel good.

I'm really starting to not understand what could be causing the engine to inject so much fuel at low loads. Are there any logs I could create? (Besides the loading pressure that I already mentioned above)?

Best regards, Tobias

Quote:

When dealing with 1.9 PD-TDI engines, VCDS doesn't show you your current position, but rather indicates where you need to be. So, if the 1° in the MWB field represents the NW, then the KW is -1° and you need to add 1° to get to zero.

For me, this means the following:

When the value in the "Measurement Block" is 1° (+), it indicates that the week is 1° ahead of the "Normal Position" (OT) compared to the "Actual Position" (NW) -------> This means that the "Cam Shaft" is running (NW is late).

If the measurement block is at (-) minus, the week (KW) is before the OT (Operating Time), compared to the positioning of the NW (Normal Welle), the KW (Kurbelwelle) runs before the NW (NW is early).

So war es zumindest damals in meiner AJM.

/viewtopic.php?t=14944

The easiest... Rotate the KW in the specified direction slowly until the marking tool of the NW just fits into the hole and check on the swing arm where the marking is located... or use the marking tool for the KW.

Aside from that, I'm not really aware of such significant differences in consumption. Are the brakes simply seized up?

Autoservice wrote:

When checking the 1.9 PD-TDI, VCDS does not show you your current position, but rather the position you need to be in. Quote: So, if the 1° in the MWB field represents the NW, then the KW is -1° and you need to add 1° to get to zero. For me, this means the following: When the value in the "Measurement Block" is 1° (+), it indicates that the week is 1° ahead of the "Normal Position" (OT) compared to the "Actual Position" (NW) -------> This means that the "Cam Shaft" is running (NW is late). If the measurement block is at (-) minus, the week (KW) is before the OT (Operating Time), compared to the positioning of the NW (Normal Welle), the KW (Kurbelwelle) runs before the NW (NW is early).

I see it exactly like that, it was also checked --> matches

Quote:

The easiest... Rotate the KW in the specified direction slowly until the marking tool of the NW just fits into the hole and check on the swing arm where the marking is located... or use the marking tool for the KW.

I completed this in the afternoon - the timing is perfect.

Quote:

Aside from that, I'm not really aware of such significant differences in consumption. Are the brakes simply seized up?

Google has many such cases, and the solution is usually that the synchronization angle is incorrect - which I have already checked several times and is correct. Brakes have been completely replaced this spring, all tools have been inspected and repaired, and all wheels are cold.


I just found a thread from someone who had a very similar problem (although there's nothing about switching from ZR, it could just be a strange coincidence).
Here's the translation:

"Subject: High Fuel Consumption on 1.9 TDI AVF Engine

Hi everyone,

I'm writing to this forum because I'm experiencing unusually high fuel consumption on my 1.9 TDI AVF engine. I'm not sure if this is a common issue or if there's something I can do to improve the situation.

I've been driving my car for a few years now, and I've always been careful about my driving habits. I don't drive aggressively, and I try to maintain a steady speed. I also make sure to keep my car properly maintained, including regular oil changes and filter replacements.

However, despite all of this, I'm still experiencing high fuel consumption. I'm getting around 25 miles per gallon, which is significantly lower than the official fuel economy figures for my engine.

I've checked for any obvious problems, such as a faulty fuel injector or a clogged air filter. I've also had my car checked by a mechanic, but they haven't been able to find anything wrong.

I'm wondering if there's anything else I can do to improve the situation. Are there any known issues with the

Unfortunately, there is no solution either... I'm starting to feel really desperate

My fuel consumption remains high... however, today in traffic, I noticed that when accelerating moderately at around 1800-2000 RPM, the engine doesn't run smoothly, and I would say that for a petrol engine, the mixture is too rich. This hasn't happened before. When accelerating with 3/4 or full throttle, it doesn't. I tried this while stationary: I slowly pressed the accelerator pedal further and further. At first, the RPM increased slowly. At around 1800-1900, the RPM stalled, even though I continued to press the pedal. Suddenly, it increased to around 2300-2400, even though I had only given it very little gas. This allows me to nicely regulate the engine speed again, but it's difficult to maintain the engine speed in a specific range, for example, between 2100 and 2500 RPM, because it either drops or immediately increases further. This wasn't the case before either. I don't think it's directly related to the timing belt, but it definitely started after the replacement. But it would fit well in my description that I need significantly more in urban traffic, and on the highway, where the RPM is higher, this problem is less or not noticeable at all.

Okay, to summarize:

- The engine requires too much diesel, especially in urban traffic.
- Timing is perfect and the synchronous angles are at 0° (without needing to be adjusted afterwards!)
- Performance drop during moderate acceleration at approximately 1800-2000 RPM, but he pulls strongly at full throttle.
- No excessive Russian development visible
- Current consumption in BC at moderate acceleration in 1st gear: 40.8 liters, in 2nd gear: 27-35 liters... Definitely wasn't like that before.
- LMM was traded in for a used one - behaves exactly the same
- AGR (for testing purposes) deactivated using a plate and screw in the hose

Which log files should I create so that I can assist you further? It would really be great if my Audi was like it used to be

Since it seems that the problems started after the change, something must have happened here as well. If the timing is correct, everything should be okay at the front. "You've probably already noticed that the bearings with guide rollers are quite stiff, I guess."

What exactly did you work on during the ZR change and the other tasks? DiFi? Something seems to be broken, possibly now somewhere, and it might be leaking and drawing in air?
Intake air hose checked? All connections are sealed, no rags, gloves or anything inside? When closing the AGR valve, did anything fall into it and enter the intake tract? Excessive buildup that has partially detached? A damaged sensor cable, incorrectly routed, loose connectors...?


Since this car is so sensitive, it must have simply registered something differently. Since you've been working on it, it must be related to that. Check all the steps, lines, and cables that you moved.

matthiasTDI96 wrote:

Since it seems that the problems started after the change, something must have happened here as well. If the timing is correct, everything should be okay at the front. Stubborn bearings in ball bearings, you've probably noticed by now, I guess.

Yes, I'm assuming that too. The question is just what I did . I can still turn the timing belt again, all pulleys including the water pump, by hand. No discernible difference from before.

matthiasTDI96 wrote:

What exactly did you work on during the ZR change and the other tasks? DiFi? Something seems to be broken, possibly now somewhere, and it might be leaking and drawing in air? Intake air hose checked? All connections are sealed, no rags, gloves or anything inside? When closing the AGR valve, did anything fall into it and enter the intake tract? Excessive buildup that has partially detached? A damaged sensor cable, incorrectly routed, loose connectors...?

I had the diesel filter replaced just 30,000 km ago. Otherwise, I had a service performed, including new air filter, complete replacement of climate O-rings, new dryer, and replacement of the valve cover gasket. I have checked for any leaks in the pipes/hoses/cables, and I have not found any. Even when accelerating to full speed next to a wall, I do not hear any hissing or other signs of a loss of boost pressure, which would lead me to believe that the problem is not related to the AGR system. However, I will still have the system pressure tested. The test phase with the AGR system is already taking some time, and I do not believe that it is the cause of the problem. I have also checked the sensor cables, and since I'm not seeing any value [or a plausible value] in the VCDS [system] for the corresponding sensor, [that suggests...]

matthiasTDI96 wrote:

Since this car is so sensitive, it must have simply registered something differently. Since you've been working on it, it must be related to that. Check all steps, lines, and cables that you moved.

I did that when I checked the ZR again (by pulling the locking bar forward etc...)
I worked with the repair manual "So wirds gemacht", which was a red book. I have trained as a commercial vehicle mechatronic technician, so it's not as if I'm completely clueless.
The only thing that is demonstrably different is the synchronization angle. But it can't be the case that if you correctly adjust an angle that was within tolerance before the change, the car will then run poorly.

That's why I want to continue using VCDS, as I've already done a lot of mechanical work myself. So far, what I've been looking at seems good, for example, the boost pressure is being achieved and the air mass is slightly above the target (without AGR).

Best regards, Tobias

Hello,

........just a silly thought:
Have you ever tried to recreate the 3° synchronization angles from before and then performed a power consumption measurement?
After all the things you've already tried and checked, there's no need to expend a lot of effort to get to the bottom of the "mystery."


As I said, just a thought

Greetings, Mpire

The idea isn't that stupid
However, I have tried this already, and it did not result in any significant changes...

Are you sure it's not just due to the cooler weather?
I find it fascinating that the oil temperature is higher.
You can only achieve this if you burn hotter or cool less.
I need to review this carefully again.
Best regards, Frank

Please check your temperature sensors.
Pot, Thermometer, Ohmmeter and a table showing the resistance to measure at which temperature.

Best regards, Frank

F B wrote:

Are you sure it's not just due to the cooler weather? I find it fascinating that the oil temperature is higher. You can only achieve this if you burn hotter or cool less. I need to review this carefully again. Best regards, Frank

Yes, that's me, I've owned my car for 3.5 years and it has 110,000 km
I checked the temperature sensors with VCDS, and even if they are a few degrees off, that shouldn't make such a big difference. G62 is only about 2 years old.

I hope I'll be able to create the log file for the boost pressure next week. I checked it again briefly today, and the boost pressure is always present and adjusts to the target value, even at low speeds, and is within the driver's desired torque range below the redline. However, when accelerating at full throttle without any engine speed, it briefly reaches the redline, which is normal. I hope I'll get around to creating the log file soon, even though I don't really expect much from it...

Greetings