Passat High Fuel Consumption: AJM & Tiptronic Issues

Hello everyone. Today is my first post, and I'm already having problems .
Specifically, I'm noticing a fuel consumption that is too high in our Passat Variant (115 hp PD engine).
When we bought the car (mileage 106,000 km), we had fuel consumption rates between 6.4 and 7.5 liters, and sometimes 8.2 liters when driven aggressively. At 120,000 km, the car received an inspection, including a new timing belt. Since then, the workshop and VW have reported that fuel consumption has rarely been below 7 liters, but everything is correctly adjusted. At 129,000 km, the catalytic converter was replaced due to a defect, and the fuel consumption increased to around 9-10 liters .
After that, the consumption was again between 7 and 8.5 liters. At 138,000 km, the mass airflow sensor (MAF) was replaced, and since then, there has been more power and no more jerking above approximately 3000 rpm. Between 138,000 km and 150,000 km, the consumption was only below 7 liters once, mostly between 7 and 8.5 liters. During the last fill-up (706 km, 52.69 liters filled, the fuel light had been on for 40 km and the gauge was deep in the reserve range), the consumption was 7.46 liters per 100 km.

What's wrong with the TDI? Somehow, I don't find the fuel consumption very typical for a diesel. My acquaintance, who has an A4 station wagon with an AFN 110PS automatic transmission, usually gets much further, often over 850km on long distances, according to him. I already had the fuel light on during a long-distance trip from Euskirchen to Berlin (650km at around 140 km/h).

I hope someone can offer advice. VW just laughed at me and said they have customers who use more fuel with the Passat }! Is that true? Does it have to be that way?
Unfortunately, I don't have a VAG-COM, so I can't measure anything myself. My passion is more with the TD engine in the T3, where I can usually figure things out. I need help with the TDI.

I can't really say anything specific about the Passat. However, my first Golf IV was an AJM model with a 6-speed manual transmission, and I ended up getting an average fuel consumption of 5.8 liters on my usual route to work (about 60 km, 2/3 highway, 1/3 country road). I wasn't driving particularly slowly, and my driving style didn't seem to have a huge impact on the fuel consumption.

Now I drive an A3 with Tiptronic and consume (on the same route) an average of 6.5 liters.

AAABEERR: If I drive the way I drove the AJM, I need 7.2 - 8 L ! For the 6.5 L, I can drive a maximum of 150 km/h and always have to go with the flow...

The lack of a sixth gear is really noticeable, and the fuel consumption is terrible above 3000 RPM. I really should have known that earlier.

The same applies to city driving/driving within urban areas. Even VW states a consumption of 9-9.2 liters. Sigh. Next vehicle expected: Seat Altea with DSG.

Regards,

Peter.

Well, that's what I thought. The consumption is probably heavily related to the Tiptronic. I think the consumption is already quite high for a 'modern' diesel. We'll probably sell the Passat and switch to something with a manual transmission. It's a shame, because otherwise the Passat has everything the heart desires. (GRA, Climatronic, central locking, electric rear windows, Nokia hands-free system, tow hitch). Let's see what else is written.

Hello,

1. Reading technical articles.
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2. Check the valve timing.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

3. Check the charge air cooler for leaks.

4. Check the EGR function, specifically the tightness of the EGR valve.

Let me know your progress when you've finished going through the list.

Best regards, Rainer.

Hello Rainer!
Here's the translation:

'How do I check the proper function of the AGR (Abgasrückführung)? I've printed out the instructions for adjusting the valve timing and will check that tomorrow. I suspect that's where the problem lies. I don't think they used any special tools when the timing belt was replaced, but rather they probably used markings (it wasn't a VW service, but an independent workshop).'
Sorry if I'm being a bit clueless, but I couldn't find anything relevant in the search results about how to check the AGR (Abgasrückführung) system.

Hi,

Look at this: https://community.dieselschrauber.org/en/viewtopic.php?t=3095

Thanks for the links/tips so far. I haven't had a chance to check the Passat yet, as my wife is currently driving it to work every day, and I have to travel abroad unexpectedly starting tomorrow. I'll let you know as soon as I've had a chance to inspect the Passat.