Top off DEF?

Wasserpest

Veteran Member
Joined
Nov 17, 2004
Location
Monterey, CA
TDI
'10 Jetta SW 6MT, '15 Jetta DSG
Is it alright to top off DEF, or do I have to wait for the low-level message to appear?
(Sorry if this is a dumb question.)
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
You can top it off whenever you want. Just be careful not to overfill it. It is also good to wait until you can fit a full container in, so no waste. I prefer not to have any sitting on a shelf.
 

scooperhsd

Top Post Dawg
Joined
Aug 19, 2003
Location
Kansas City KS
TDI
NB, 2000, RED(5 Speed conversion) 2015 Golf SE
I wait until the low level warning shows, then fill up with 2.5 gal of DEF. I kind of wish there was a way to tell how much is in there.
 

Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
IIRC you start getting the warning at 1500 miles. When the warning comes on buy 2 cubes and wait till it gets to 500 or so miles and fill. It should take most of the 5 gallons.
 

Wasserpest

Veteran Member
Joined
Nov 17, 2004
Location
Monterey, CA
TDI
'10 Jetta SW 6MT, '15 Jetta DSG
Thanks for the replies guys. This is for my wife's car. I am going to be away for a while and don't want her to to have to deal with it.
So I was thinking of buying a 2.5 gal box and just top it off. There's no way to tell how much is in there, right? If I don't use all of it does it go bad until it's needed the next time?
I'm new to this DEF stuff. Great mileage though.
 

oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Fill it at every service, or when the warning comes on, OR if you know it has not been recently filled for one of the above reasons and you are taking the car on a trip (or in your case, a just as valid excuse of not wanting your wife to have to mess with it), then you can certainly top it off.

Just be sure to use as "small" of a container as possible, so as not to have to break the seal and have a bunch of leftovers in an opened container. Because it can slowly evaporate once it is opened, and the containers' caps often do not seal up as tight as they did when new.
 

Growler

Got Soot Vendor
Joined
Nov 24, 2003
Location
Millersport, Ohio
TDI
Schmutz, 2015 Golf Sportwagen DSG & Schnurren, 2001 Golf GL 2 door 5M
so if I have been refilling every oil change, and not getting the full 2.5 gallons in I should wait longer than every 10k miles to refill my DEF so I can get the whole 2.5 gallon jug in..

and the capacity is over 5 gallons? I had no idea. if thats the case, I can do my def fills every other oil change with almost 2 whole cubes and still be alright..
 

Mike_04GolfTDI

Top Post Dawg
Joined
Nov 19, 2003
Location
Richmond, BC, Canada
TDI
Mine: 2019 Golf R DSG, Wife's: 2015 Golf Comfortline TDI
I kind of wish there was a way to tell how much is in there.
VCDS can show you the level on a 2015 Golf.

Earlier models apparently didn't really have a level sensor, they just had a full or low sensor. In between those sensors you wouldn't know what the level was.

Apparently that changed on the 2015 MQB platform (So Golf only, not Jetta), because I've watched the level go up with VCDS while filling it. Also if you shake the car around a bit the level changes (shows in mm) as the fluid sloshes around. There definitely must be a proper level sensor if it can show that.
 

Wasserpest

Veteran Member
Joined
Nov 17, 2004
Location
Monterey, CA
TDI
'10 Jetta SW 6MT, '15 Jetta DSG
Thanks again for the helpful replies & discussion.

I just bought the car with <20k miles on it and have no clue if the dealer topped up the DEF, nor how fast it is being used up (post-fix). Don't have a VCDS. But...

Can I "go 20th century" and just stick a (cleanly shaven) wooden stick in there and see if it seems to be full?

Alternatively, I may just buy a gallon of it and chuck it in there and hope that will last until I am back.
 
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Lightflyer1

Top Post Dawg
Joined
Sep 13, 2005
Location
Round Rock, Texas
TDI
2015 Beetle tdi dsg
Is your fill port in the fuel fill area? If so filling the def is a pretty easy affair. I would just buy a cube and put it in the trunk. Show her how to do it and let her do it. If you can put fuel in the car you can fill the def tank as well. Isn't really any harder than that. Kind of like filling with a spare tank when you run out of gas in other cars. The cube has its own built in nozzle and all you have to do is open the cube and put the nozzle on and pour it in. If the warning comes on she has quite some time to do it or go by and let someone else help her do it. Not a big issue.
 

MichaelB

Veteran Member
Joined
Aug 11, 2009
Location
SE Wisconsin
TDI
2014 Passat SE DSG
Thanks again for the helpful replies & discussion.

I just bought the car with <20k miles on it and have no clue if the dealer topped up the DEF, nor how fast it is being used up (post-fix). Don't have a VCDS. But...

Can I "go 20th century" and just stick a (cleanly shaven) wooden stick in there and see if it seems to be full?

Alternatively, I may just buy a gallon of it and chuck it in there and hope that will last until I am back.

The community here is making a very simple task sound complicated. If you top up the DEF now you will never have to worry about your wife running out. If by some slim chance she does you have 1500 miles to go to top it up I hope that she is never that far from home in here car without you. :) In reality, it is no more difficult than filling the windshield washer fluid, with the exception of not wanting to spill any. That being said your car has the fill port on the outside and if you do overfill and spill it just washes off with water. The previous Passats had it in the trunk and if you overfilled it stained the inside of the trunk with urea crystals. Filling the DEF tank is easier than changing a tire.
 
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Wasserpest

Veteran Member
Joined
Nov 17, 2004
Location
Monterey, CA
TDI
'10 Jetta SW 6MT, '15 Jetta DSG
Is your fill port in the fuel fill area? If so filling the def is a pretty easy affair. I would just buy a cube and put it in the trunk. Show her how to do it and let her do it. If you can put fuel in the car you can fill the def tank as well. Isn't really any harder than that. Kind of like filling with a spare tank when you run out of gas in other cars. The cube has its own built in nozzle and all you have to do is open the cube and put the nozzle on and pour it in. If the warning comes on she has quite some time to do it or go by and let someone else help her do it. Not a big issue.
Very easy for you and me. I will just top it off with a gallon and be done with it. Thanks for all the help!

The community here is making a very simple task sound complicated. If you top up the DEF now you will never have to worry about your wife running out. If by some slim chance she does you have 1500 miles to go to top it up I hope that she is never that far from home in here car without you. :) In reality, it is no more difficult than filling the windshield washer fluid, with the exception of not wanting to spill any. That being said your car has the fill port on the outside and if you do overfill and spill it just washes off with water. The previous Passats had it in the trunk and if you overfilled it stained the inside of the trunk with urea crystals. Filling the DEF tank is easier than changing a tire.
Let's not oversimplify this. ;)

(The '15 Jetta has the fill hole inside the trunk).
 

MichaelB

Veteran Member
Joined
Aug 11, 2009
Location
SE Wisconsin
TDI
2014 Passat SE DSG
Let's not oversimplify this. ;)
(The '15 Jetta has the fill hole inside the trunk).

OK, I bought this to prevent spills in my trunk.
https://www.ecstuning.com/b-genuine...LPToP4cVR4a4RZBtOHOmYVGnk-78a21hoCAa4QAvD_BwE


and I bought this https://www.ecstuning.com/b-genuine-volkswagen-audi-parts/urea/gus052910a3/


which I can refill from any truck stop pump which is less expensive than the Walmart cubes and way less expensive than the genuine Ad Blue Kruse bottles that the dealer sells.. Hopes this helps, again I say with a little research it is Simple Simon. The hose fits the jug perfectly.
The other end of the hose fits the threaded filler pipe perfectly and will not allow you to spill in your trunk just like the KRUSE bottles don't. No muss no fuss.

Again I say hope this helps.:)
 
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oilhammer

Certified Volkswagen Nut & Vendor
Joined
Dec 11, 2001
Location
outside St Louis, MO
TDI
There are just too many to list....
Oh it is within the realm of normalcy for TDI club to make something so simple turn into an 11ty page long thread. :)
 

tdiatlast

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Joined
Jan 21, 2009
Location
Fort Worth, Texas
TDI
2009 Sportwagen (boughtback); 2014 Passat TDI SEL (boughtback)
Okay, OH, I'm going to continue flogging this dead horse, and...I don't even have a horse in this race!

Have you noticed if the tank internals are better protected from corrosion if continually immersed in AdBlue? I recall speculation early on that running the tank mostly empty vs. mostly full might be a contributing factor in AdBlue pump failures.

For sure, an OCD question, but...your experience is valuable.
 

MichaelB

Veteran Member
Joined
Aug 11, 2009
Location
SE Wisconsin
TDI
2014 Passat SE DSG
Okay, OH, I'm going to continue flogging this dead horse, and...I don't even have a horse in this race!

Have you noticed if the tank internals are better protected from corrosion if continually immersed in AdBlue? I recall speculation early on that running the tank mostly empty vs. mostly full might be a contributing factor in AdBlue pump failures.

For sure, an OCD question, but...your experience is valuable.

It might be interesting for you to start a poll.........
1 I keep the DEF tank topped up at all times
2 I refill it at the 10k service interval
3. I wait till the message comes on the MFI
4. I ignore it until it becomes a problem
5. I have had DEF pump issues
6. I have never had a DEF pump issue.
 

Rico567

Top Post Dawg
Joined
Jun 13, 2003
Location
Central IL
TDI
2013 Passat TDI SEL Premium (Turned in 7/7/18)
I have filled at every OC since the free services expired. It takes the 2.5 gal. jug just about perfectly. One time it took all but a few ounces, and I just dumped the rest. At $6.99 a jug at Rural King, who cares? Filling is simple for me, as initially I found a deal on the M-B 10 liter jug and hose, which hooks up and self-vents. So, just connect up and let it fill....no spills, no muss, not much to it.
 

bizzle

Veteran Member
Joined
May 21, 2013
Location
Southern California
TDI
2015 GSW SEL (totaled), 2013 Touareg Executive
I have an extra one of those filling contraptions that was just posted that I'd be willing to drop by someone's place in Southern California (or mail it, but then it might be the same price as ordering new).

I don't think you can overfill the tank because the nozzle pushes on and I don't know if it's vacuum pressure or not but eventually it will stop accepting fluid. You can hear it, too, because as the fluid fills there is less air space and the sound will change. It doesn't take but a few minutes.

I got together with a few buddies and we all serviced our Golfs so I had bought those fill contraptions for each of us, but it turns out the process is like 5-10 minutes and doesn't need to be done very often (thought it was going to be like every fuel fill!) so we only ended up using one. I don't think I'm going to fill mine up to the top next time, though. By the time the tank is halfway empty, the fluid will probably be nearing the end of life...unless the tank is air tight and if being air tight makes the difference.

The gauge, btw, isn't particularly accurate. I think it was telling us our tanks were 100% full when they were only about halfway there. Trying to think of anything else, but only other thing is if you *do* manage to spill some on the driveway or whatever make sure you wash it off.
 

scooperhsd

Top Post Dawg
Joined
Aug 19, 2003
Location
Kansas City KS
TDI
NB, 2000, RED(5 Speed conversion) 2015 Golf SE
The "store brand" at WALMART that comes in the 2.5 gallon container hase a hose that fits perfectly on my 2015 Golf. Just put the hose into the DEF fill port, open the vent on the DEF container and just lift it up until the container is empty.
 

MichaelB

Veteran Member
Joined
Aug 11, 2009
Location
SE Wisconsin
TDI
2014 Passat SE DSG
The "store brand" at WALMART that comes in the 2.5 gallon container hase a hose that fits perfectly on my 2015 Golf. Just put the hose into the DEF fill port, open the vent on the DEF container and just lift it up until the container is empty.

If your tank will not accept the full 2.5 gallons you are going to have a spill.
 

Blue_Hen_TDI

Top Post Dawg
Joined
Oct 23, 2005
Location
Slower, DE
TDI
owned: 96 B4V, 06 Golf, 12 NMS, 15 GSW
If your tank will not accept the full 2.5 gallons you are going to have a spill.

Luckily, he has a Golf, so it's right there next to the fuel filler. Just put the cap back on, run a few ounces of water through the drain hole and motor on.


In my old Passat, the filler was in the trunk, so I had to actually be careful.
 

berks_tom

Veteran Member
Joined
Jan 23, 2006
Location
West Chester, PA
TDI
2013 Passat TDI SEL
If your tank will not accept the full 2.5 gallons you are going to have a spill.
If you wait to fill until the warning comes on, you won't have a problem fitting the entire 2.5 gallon container into the tank.

Why worry about topping off the tank? The car doesn't need DEF _that_ often.
 

vinny6737TDI

Active member
Joined
Jun 15, 2014
Location
Ottawa, Ontario, Canada
TDI
13PassatTDI HighLine
My AdBlue 'low' light just came on after 40,000kms from the time I bought the 2013 Passat TDI HighLine. My mechanic offers to top it up at each oil change but in my mind, it's not needed that often. I wouldn't know what the level was when I bought it at 106,000kms.
 

brownnugen

Veteran Member
Joined
Jan 18, 2001
Location
Charleston, SC
TDI
2015 GSW TDI, 2011 JSW TDI & 2018 Atlas 2.0T S
Here is one data point here: on my 2015 GSW, my DEF warning came on around 15,200 on the odometer, letting me know I had 1,500 mile remaining until empty. I drove it another 200 miles (1,300 miles till empty) and bought a 2.5 gallon cube at Walmart. After putting all of it in the tank, the MFI indicated I now have 10,000 until I run out of DEF. so, if my math is correct, each 2.5 gallon cube should be good for about 8,800 miles. I’d round down to 8,500 miles.
 
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