Inconsistent DEF usage

kbsilver · 05-18-2014, 06:22 PM

So the xxx miles to no start went off early in the oil change cycle. I just figured they never filled it completely last time. No biggie, added 1 gallon of DEF into active tank. I've driven 3000 miles since and the low DEF alert has never come back on? With a ratio of 1.5% it should have used 1.5 gallons in 3000 miles. It's almost like the passive tank was not really empty, but there was a transfer problem that cleared itself. Thoughts or any experiences in this area? I'm going in for my last free service next week. I do have an extended warranty.

floydarogers · 05-18-2014, 10:02 PM

Quote:

Originally Posted by kbsilver

So the xxx miles to no start went off early in the oil change cycle. I just figured they never filled it completely last time. No biggie, added 1 gallon of DEF into active tank. I've driven 3000 miles since and the low DEF alert has never come back on? With a ratio of 1.5% it should have used 1.5 gallons in 3000 miles. It's almost like the passive tank was not really empty, but there was a transfer problem that cleared itself. Thoughts or any experiences in this area? I'm going in for my last free service next week. I do have an extended warranty.

It's not an uncommon problem for the transfer pump/piping to get clogged. I believe that mine currently is in that state, as the passive tank won't take any, but the active tank will take 2 gallons when the light comes on.

But it doesn't make sense to spend $3K for a new tank to fix the problem (out of warranty.)

Mark M · 05-19-2014, 08:32 AM

There is a company in Canada that specializes in reconditioning the urea tank at an affordable rate. I can't seem to find the link, but recall posting it in another thread on here some time ago.

Found it. $499

http://www.xemodex.com/technologyimp...eturn-for-bmw/

grzes · 05-21-2014, 01:31 AM

it is know fact that DEF crystallizes over time but does anyone know if crystallization in the passage occurs when the passive tank is empty or can it happen even if both tanks are full of DEF solution? I had some issues with my tank and had it recently replaced under the warranty but to prevent crystallization of the passages I would like to know if keeping both tanks full will take care of this issue. I don't mind adding DEF once a month just to avoid this issue. The car is still under the extended warranty so this time it did not cost me anything but what if warranty is gone

05-18-2014, 06:22 PM	#1
kbsilver Captain 143 Rep 631 Posts Drives: 340GT & '22 eDrive40 Join Date: Jan 2012 Location: North Jersey iTrader: (0)	Inconsistent DEF usage So the xxx miles to no start went off early in the oil change cycle. I just figured they never filled it completely last time. No biggie, added 1 gallon of DEF into active tank. I've driven 3000 miles since and the low DEF alert has never come back on? With a ratio of 1.5% it should have used 1.5 gallons in 3000 miles. It's almost like the passive tank was not really empty, but there was a transfer problem that cleared itself. Thoughts or any experiences in this area? I'm going in for my last free service next week. I do have an extended warranty.
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05-19-2014, 08:32 AM	#3
Mark M Major 245 Rep 1,294 Posts Drives: E30M3 E83X3 E90335D Join Date: Aug 2007 Location: Lancaster, PA iTrader: (0)	There is a company in Canada that specializes in reconditioning the urea tank at an affordable rate. I can't seem to find the link, but recall posting it in another thread on here some time ago. Found it. $499 http://www.xemodex.com/technologyimp...eturn-for-bmw/ __________________ Last edited by Mark M; 05-19-2014 at 08:45 AM..
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05-21-2014, 01:31 AM	#4
grzes Captain 34 Rep 655 Posts Drives: 2009 bmw 335d LCI Join Date: Feb 2014 Location: Alberta iTrader: (2)	it is know fact that DEF crystallizes over time but does anyone know if crystallization in the passage occurs when the passive tank is empty or can it happen even if both tanks are full of DEF solution? I had some issues with my tank and had it recently replaced under the warranty but to prevent crystallization of the passages I would like to know if keeping both tanks full will take care of this issue. I don't mind adding DEF once a month just to avoid this issue. The car is still under the extended warranty so this time it did not cost me anything but what if warranty is gone
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