[cschmelz]

So I ran out of DEF between oil changes (maybe because of my lead foot, maybe because the dealership didn't fill it right) and got the dreaded "1000 miles to no start" message.

I bought 2.5 gallons with the weird hose from AutoZone for $15 and by pouring slowly got the active (lower filler) tank filled and put a little in the passive tank.

Still had a 'no start in 974 miles' message. I went and bought 2 of the 0.5gallon VW AdBlue bottles and confirmed the active tank was full. I put the other 1 gallon in the passive tank and STILL got the "no start" message.

I was basically like "screw it" and decided to just drive the car for a while. After about 10-15 miles of driving the "no start" indication was gone.


Just a word of warning if you think you filled it enough and it still gives you the message, just drive a bit. Might fix the problem like it did for me.

[usna2k]

That's normal actually. It takes the computer system a while to register that you've filled the tanks back up.

[Mark M]

Heard the passive tank can't be filled without pressurization? Read on here that the larger passive tank sits higher up than the fill port, so to fill it full you need a pressureized charge?

What is your experience?

I've thought about jacking the left rear of the car up high so as to allow a fill up of the passive tank.

Also, from what I've read this is my understanding:

- The passive tank is ~4 gallons.
- The active tank is ~2.5 gallons.
- The active tank is heated and feeds the exhaust injection with DEF.
- The passive tank is not heated but has a pump whose job is to meter in DEF to the active tank to keep it full.
- DEF freezes at ~25 degrees F.
- DEF ages quickly and can crystalize components.

Under that logic, wouldn't the ideal approach be to always fill the passive tank when low and let the pump do its job thus minimizing the aged DEF in the system? (Unless you are in a pinch and need DEF in the active immediately)

Just asking based on what I've read, have only had my 335d less than two weeks now.

[F32Fleet]

Originally Posted by Mark M

Heard the passive tank can't be filled without pressurization? Read on here that the larger passive tank sits higher up than the fill port, so to fill it full you need a pressureized charge?

What is your experience?

I've thought about jacking the left rear of the car up high so as to allow a fill up of the passive tank.

Also, from what I've read this is my understanding:

- The passive tank is ~4 gallons.
- The active tank is ~2.5 gallons.
- The active tank is heated and feeds the exhaust injection with DEF.
- The passive tank is not heated but has a pump whose job is to meter in DEF to the active tank to keep it full.
- DEF freezes at ~25 degrees F.
- DEF ages quickly and can crystalize components.

Under that logic, wouldn't the ideal approach be to always fill the passive tank when low and let the pump do its job thus minimizing the aged DEF in the system? (Unless you are in a pinch and need DEF in the active immediately)

Just asking based on what I've read, have only had my 335d less than two weeks now.

Makes sense but of course you're filling more often.

[Mark M]

Originally Posted by Socom

Makes sense but of course you're filling more often.

Not sure how you meant you'd be filling more often?

If you fill the passive tank only you would be filling less often. (4 gallon capacity as said above)

If you only fill the active tank, then your logic is true and you would be filling more often.

[335dFan]

Originally Posted by Mark M

Not sure how you meant you'd be filling more often?

If you fill the passive tank only you would be filling less often. (4 gallon capacity as said above)

If you only fill the active tank, then your logic is true and you would be filling more often.

Dumb guy question: Am confused---if the passive tank is feeding the active tank, then why would you ever fill the active tank? Unless the mechanism to transfer from passive to active is not working, then you have a problem anyway.

[Pierre Louis]

I just fill the passive tank by gravity and then put some in the active tank. Works fine after driving a bit. Don't think it needs to be pressurized.

PL

[F32Fleet]

Originally Posted by Mark M

Not sure how you meant you'd be filling more often?

If you fill the passive tank only you would be filling less often. (4 gallon capacity as said above)

If you only fill the active tank, then your logic is true and you would be filling more often.

Total capacity is 6 gal. Filling only passive means you'll be 2 gal short. So you'll fill more often over X miles (ex 9k vs 13k miles).

[Mark M]

Originally Posted by Socom

Total capacity is 6 gal. Filling only passive means you'll be 2 gal short. So you'll fill more often over X miles (ex 9k vs 13k miles).

Ok, gotcha. I think we were misunderstanding each other.

The point I was making is that some people seem to only refill the active tank, thereby shortening their possible driving duration and also neglecting the critical regular operation of the passive tank to circulate the DEF.

I was inferring that really filling the passive tank should be done and let the passive tank meter the DEF into the active tank to allow all mechanisms to work properly.

[hrc630]

I have filled both tank with no problem (long, but easy)

[GreekboyD]

My passive tank won't receive any urea. It's most likely a plugged valve.

[DaBrass]

I just refilled this weekend. I essentially filled the Passive tank first, drove around the block until the warning went out, then topped up the Passive tank again. After the Passive was full, I topped up the Active tank and now the back end feels heavier.

After driving it...there was a bit of vacuum seal while opening the caps, but nothing else.

I'd say in total, I used about 15L out of the 19.5L I bought (2 jugs). Works out to about 4 out of the 5 gallons.

[F32Fleet]

Originally Posted by DaBrass

I just refilled this weekend. I essentially filled the Passive tank first, drove around the block until the warning went out, then topped up the Passive tank again. After the Passive was full, I topped up the Active tank and now the back end feels heavier.

After driving it...there was a bit of vacuum seal while opening the caps, but nothing else.

I'd say in total, I used about 15L out of the 19.5L I bought (2 jugs). Works out to about 4 out of the 5 gallons.

IIRC the active tank is re-filled 3 liters at a time by the passive tank. This may explain any inconsistencies.

[rogerdiaz]

The active tank is the lower nozzle correct? Has a blue ring says urea refill? I got the warning light but urea wont go in. Few ounces goes in and then starts spitting out/overflowing. ?

[335dM]

http://www.e90post.com/forums/attachment.php?attachmentid=513011&d=1303262242

[rogerdiaz]

Originally Posted by GreekboyD

My passive tank won't receive any urea. It's most likely a plugged valve.

Any updates to your issue? I am having the same problem for first time.

Started refilling. Was flowing nicely did about 1 Liter. Started to rain so stopped the operation. Screwed on caps. Went back out to redo. Heard a vacuum suck noise when I unscrewed lower filler. No urea won't go in. Few ounces and then starts overflowing. Very strange.

[GreekboyD]

I honestly didn't bother looking into it yet. I had two weeks off in June but the thought of not having my car for over a week turns me off.

[rogerdiaz]

Originally Posted by GreekboyD

I honestly didn't bother looking into it yet. I had two weeks off in June but the thought of not having my car for over a week turns me off.

well maybe I just entered the twilight zone. I decided to fill the upper nozzle and it worked. It took the 2.5 gallon without a problem. Tommorrow I am going to buy another. Drove around and dash light is off.

[Hoooper]

I havent seen any good diagrams of our tank/filler neck but I would guess that if you have crystallization in the filler neck you could open up the drains in the tank and blast some warm water at it until the crystals dissolve and the filler is opened up again.

If you are using something funnel-like that has a somewhat tight fit into the filler neck and filling up the funnel too quickly the tanks dont breathe fast enough and start to bubble out. I had much better success putting the funnel just into the filler neck, not sticking it in very far so that there was a large air gap at the mouth of the filler neck, that allowed me to fill much more quickly than when I tried it with the funnel sealing at the filler neck. Image of what I mean below

[335dM]

For me i bought the VW bottle that you can screw, bought a 5 gallon of def at my local auto part and cut the bottom of the VW bottle, screw it to my the lower nozzle then when filled up , the upper one and ask my friend to fill it with the big 5 gallon while I push and hold the VW bottle.

[Quasimodem]

Originally Posted by GreekboyD

My passive tank won't receive any urea. It's most likely a plugged valve.

This is why I only fill the passive tank. My theory is that the valve needs to be constantly used so it doesn't stick due to crystallization. If you fill the active tank full, IMHO the short time lack of use of the valve could cause it to get plugged up.

But I am not an expert.

[TDIwyse]

Good suggestions/advice on filling. Thanks.

Any of you buy bulk DEF? The truck stop near me added a bulk DEF dispenser. $2.69/gallon. Will eventually need to start doing this myself ...