mrsgrey2015

I had my 2015 Q7 tdi to the dealer in early Feb for the computer reflash (per letter received late 2019.) While they had it I requested them to fill the adblue(they did, supposedly.) Drove it home 60-80 miles and I had the adblue warning come on. Drove it a couple of days and the warning turned off. Now 2 months and roughly 3000 miles later the adblue warning came on again and has stayed on. I have a hard time believing that in 3000 miles I have gone through that much adblue (prior usage was roughly 10,000 miles between refills.) Has anyone noticed increased adblue usage with the latest computer reflash? I have an appointment at the dealer but am looking for any ideas or experiences from the forum. I have a feeling there is something else wrong (sensor, etc.) Any guidance would be appreciated.

Timtheguru

With the original fix you can use up to 80% more adblue, per the documentation of the TDI fix.

If I had to wager, I'd bet they didn't fill it up all the way, and especially didn't fill the secondary tank that can be difficult to "burp" (without the specialized equipment) to allow more adblue to be poured into the vehicle.

dreadlocks

yeah they just refilled the upper tank, 3k miles is about what I would see when I didnt take the time to fill up both tanks fully.

mrsgrey2015

They said they added 15 gallons. I'm wondering if it was actually 15 liters because from what I understand it takes 24 liters for the system.

dreadlocks

its a ~6 gallon capacity so they did not add 15 gallons to it... IIRC its like 2g for upper tank and 4g for lower.. or something like that.. you gotta fill the upper tank three times basically if its empty, and let it burp down to lower tank between.. I park it on an incline because if its level it can take forever to transfer.. I usually buy 2x 2.5g boxes of DEF, that almost fills it up.. my mileage between refills is highly variable due to my towing.

those days of buying and handling boxes of **** are behind me thankfully

J. Patterson

Most likely they didn’t fully fill it but the transfer pump that pumps it up to the operating tank can fail and you only get the Adblue from the upper tank. It will last about 3000 miles. This happened to our 2012 back before the emissions buy back. It would call for Adblue but would only hold about 1 1/2 gal. No MIL or code was present. I paid to have it replaced and all was well. Then Audi bought that one back. :-/. You can diagnose yours by measuring how much it holds next time it calls for Adblue. It does tend to air lock though and be stubborn flowing down to the lower tank. Helps to rock or shake the vehicle.

Kei78

Dread, did you get yours finally tuned?

meooem22

I have not had to fill adblue tank yet, What's the best way to park car on incline to fill? Front up? Or one side up?

dreadlocks

Its at the dealer right now, with a trunk full of rawtek exhaust and the tuner in the glovebox.. went to go void my warranty last Saturday and about 5mins after I put it on the lift I found the rear main seal was leaking, so I lowered it and drove it directly to Audi Denver.. they are fixing the rear main, and re-sealing the upper oil pan.. probably gonna take a few weeks before I get it back and tune it.

In the meantime, I've figured out how to retrofit a Webasto parking heater to my Q7.. obtaining parts for it right now, I'll make a post about it here in a few weeks.

dreadlocks

any incline should do, I live on a hill so I just park on the street with nose up.. you just trying to stop it from vapor locking w/the gravity transfer which just seems to need taken off level ground.. looking at the diagrams it seemed to me that *** up and nose down would work the best but the hill infront of my house dont work that way and I'd be standing in the street.