Mehrverbrauch nach Zahnriemenwechsel 1.9TDI AVF | Posts 48+

dieselschrauber wrote:

Quick Diagnosis: EDC15 (old engine control unit) might be the cause.

Hmm, that's a shame, then dealing with the log files will naturally be difficult...
What do you think about the pump-nozzle cable harness? I replaced the VDD during the service, didn't see anything externally, and I also can't imagine that anything happened or that it has anything to do with the consumption. But recently, we replaced the PD cable harness on a 2.0TDI 16V, and as a result, it started and ran much smoother...

Maybe it will also be useful for me?

Best regards,

Tobias

I'm also continuing to write here...

The problem with fuel consumption persists, and I have now driven over 8000 km. The PD (Power Delivery) components have been discontinued, and the PD cable harness has been replaced. The temperature sensors have been checked multiple times for plausibility. The error memory is still empty.

What I did notice, however:

If I drive a short distance (approximately 10-15 minutes) and then park the car, even for several hours, the fuel consumption is lower on a subsequent, longer trip. For example, the car is parked for one day, and then I drive 250km in the evening --> Consumption is approximately 6.5 liters.
However, if I drive a short distance in the afternoon and then another 250km in the evening (with the engine starting but not getting warm again), the fuel consumption is approximately 6 liters. I have noticed this several times, so I do not believe it is due to chance. (I believe that weather, temperatures, tire pressure, etc. can be ruled out, as I have enough comparable "measurements/observations")

Maybe this tip will help someone else too, and ultimately me

Best regards from sunny Switzerland

Tobias

Sorry, that I'm bringing this thread up again after a year, but I'm experiencing exactly the same problem:

A4 B6 1.9 TDI AVF. Zahnriemen / Rollen / Wasserpumpe ausgetauscht, Synchronisationswinkel auf 0° eingestellt, seitdem messbar höherer Verbrauch. Just like with the theme creator, approximately 1 liter / 100 km more on the highway, and even more in the city.

The engine runs perfectly, with no jerking, excellent cold start, and full power. All measurements are plausible and unremarkable.

It's like a curse.

How many tkm was the increased consumption measured over?

A rather peculiar suggestion.

If the engine runs differently after only the timing belt has been replaced, it can only be due to incorrectly (or differently) set timing.
Behind this can be false tracking, incorrect tracking tools (KW Stop), changed synchronization angle, but also a faulty KW position sensor that was bent or damaged during repair.
Unless you have touched anything else that could affect the engine's operation (temperature sensor, turbocharger boost control, EGR control), and haven't paid attention.
It remains to go through the points one by one, including each individual plug.
Otherwise
/viewtopic.php?t=5408
However, I would prefer to leave the PDEs alone.
hg
Herbert

If anything has changed since the work on the engine, the only way to succeed is to compare all the affected parts before and after. Even just when setting up the PD elements, enough can change (you don't know how it was before), and there are enough potential sources of error and things you can get wrong.

Plus Diagnosis on the Engine Control Unit to check if there is possibly The measurements are inaccurate, meaning that they were temporarily malfunctioning.

Best regards, Rainer

Hi,
a question mark: Have you ever considered whether "soft" spools could cause a problem?
We know that the tensioning rollers are subject to movement and vibration when the motor is running under varying loads. As the speed increases, the angular displacement of the synchronization angle in the synchronous roller can vary depending on the characteristics of the spring.
hg
Herbert

Or, or, or...

Quote:

However, if I drive a short distance in the afternoon and then another 250 km in the evening (with the engine starting but not getting warm again), the fuel consumption is approximately 6 liters.

That a warm engine spins more easily than a cold one is hardly a surprise.

It is also conceivable that a different type of engine oil was used, which is thicker at cold starts, etc.

I find the idea of using a timing belt interesting. I have installed the timing belt kit from Contitech (CT1028WP4) in my car. The car still behaves the same as it did a year ago. Since the change, I have driven approximately 32,000 km. The oil is the same as before and has been changed in between. I have now accepted this, as no one else knew what to do. The engine is still running smoothly, starts up nicely, etc. I will install the old timing belt at some point to compare, it would be interesting to find the solution

@qwnz: Which timing belt kit did you install?

Best regards, Tobias

@Rüdi: We have now used up almost 5 complete tanks.

Real fuel consumption is approximately 6.5l/100km per tank. The on-board computer currently shows 6.2 l/100km.

The previous mileage of 240,000 km was actually 5.0-5.5 l/100km, except that the FIS always reported figures below 5 l for extra-urban driving. I really can't do this anymore.

However, I am also a slow driver and only use the car for commuting (almost no city traffic, only country roads and a short stretch of highway at 120 km/h).

@tobias_: It's a Contitech CT1028WP2 (The A4 is MJ2004). I had that one in the last interval as well

Were the tires changed around the same time as the belt?

I once had a set of tires with a diameter that was about 1cm smaller than the worn tires (so they were definitely 2cm smaller than new). The old and new tires had the same dimension printed on them, but they were from different manufacturers (I think Michelin to Fulda). After that, my car surprisingly consumed less fuel both according to the MFA and when refueling. This was no surprise, as the car thought the distance traveled was longer. In addition, I was actually driving slower (with the same speedometer reading) due to less wind resistance. I don't remember exactly how much the difference was, but overall, it was significant. So, wenn Sie also (unbewusst) Reifen mit größerem Umfang oder höherem Rollwiderstand usw. gewechselt haben...