High fuel consumption on Passat with AJM engine and Tiptronic transmission

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 were getting fuel consumption figures between 6.4 and 7.5 liters, sometimes as high as 8.2 liters when driven aggressively. At 120,000 km, the car had 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 KM 129000, the catalytic converter was replaced due to a defect, and the fuel consumption is around 9-10 liters .
After that, the fuel consumption was 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 fuel 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 to be very typical for a diesel. Also, a friend of mine in an A4 station wagon with an AFN 110PS automatic transmission always gets much further, usually over 850km on long trips, according to him. I've already had the fuel light come on during a long-distance trip from Euskirchen to Berlin (650 km at around 140 km/h) .

I hope someone can offer advice. VW just laughed at me and said they have customers who use the Passat and consume more fuel ! That's how it is, it has to be that way.
Unfortunately, I don't have a VAG-COM, so I can't measure anything myself. My passion is more focused on the TD engine in the T3, and I know how to troubleshoot that. I need help with my TDI.

Regarding the Passat, I can't really say anything specific. 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 commute to work (approximately 60 km, 2/3 highway, 1/3 country road). I was never particularly slow, and the fuel consumption wasn't really affected much by my driving style.

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

AAABEERR: But, if I drive the way I drove the AJM, I need 7.2 - 8 liters ! For vehicles with a 6.5-liter engine, the maximum speed allowed is 150 km/h, and it's important to maintain a safe following distance.

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

By the way, the same applies to urban driving. Even VW states a consumption of 9 - 9.2 liters. Sigh. Next vehicle available: Seat Altea with DSG transmission.

Regards,

Peter.

'I thought as much. The consumption seems to be heavily influenced by the Tiptronic transmission. I find the fuel consumption a bit too 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 you could want (GRA, Climatronic, central locking, electric rear windows, Nokia hands-free system, tow hitch).' Let's see what else is being written.

Hello,

1. Reading technical articles.
/content.php?c=8

2. Check valve timing.
Okay, I'm ready. Please provide the German text you want me to translate.

3. Check the charge air cooler system for leaks.

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

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

Best regards, Rainer.

Hello Rainer!
How do I check the proper functioning of the AGR (Abgasrückführung)? I've printed out the instructions for adjusting the valve timing and will check that tomorrow. I suspect the problem lies there. I don't believe any special tools were used for the timing belt replacement, but rather that markings were used (this wasn't a VW service center, but an independent workshop).
'Sorry if I sound silly, but I couldn't find anything relevant in the search results about how to check the EGR valve.'

Hi,

Please see here: /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 checked the Passat.