[atropine]

So I have tried searching but am having a hard time finding the right info. I'm about ready to dive into the DPF/SCR deletes and install the ATM downpipe/exhaust/intercooler/intake. I already have the EGR block off installed. I would like to drain the DEF tanks and fill them with distilled water so if the next owner needs to return it to OEM they can. Is there a DIY for this process somewhere?

[Torqu3]

To drain: http://www.e90post.com/forums/showth...1089933&page=3

If you're going to refill them to prevent crystallization, you'll have to flush them out thoroughly with distilled water, and then dump in more distilled water to store. Otherwise you're wasting your time.

[aaddam2]

so i was going to say water is a horrible idea...but i see you are located in Navada so probably wont freeze, but i would still think you would want something like anti-freeze mixed with water or wiper fluid that would resist freezing for w.e. reason you are in a cold area.

[Torqu3]

Originally Posted by aaddam2

so i was going to say water is a horrible idea...but i see you are located in Navada so probably wont freeze, but i would still think you would want something like anti-freeze mixed with water or wiper fluid that would resist freezing for w.e. reason you are in a cold area.

I actually talked to BPC about this a long, long time ago. I was told the ambient heat from the exhaust will keep the water thawed. However, if anyone is trying to save the tanks in case they want to go back to stock at some point, I would say just flush them out with distilled water, and leave them completely empty.

[atropine]

Thanks for those links- that is what I was looking for. But it looks like to really do a good job of draining the urea I would need the special BMW pump apparatus or the electrical equipment/knowledge to activate the urea pump to flush the water thru. Maybe it's not worth it? If I just leave the system full of urea will it crystallize inside the tank over time?

[BB_cuda]

Nevada is a pretty cold place in the winter at least at higher altitudes. Warm exhaust won't be a factor when parked overnight either. I think a little antifreeze mixed in would be prudent other than completely draining (how does one know if system is really purged?).

[Owen81]

There are two drain tubes on the driver side of the tanks that make draining them quite easy if you have some patience. I used a Mityvac extractor to speed up the process significantly, then added some water to both tanks, drove around trying to slosh it as much as possible then drained them again.

As I live in Canada, I put a few gallons of low temp washer fluid in there and called it good. If you want you could drive around pre-deletes with the SCR metering valve exposed to atmosphere and it will pump some of the water/fluid out for you. You will get some SCR codes which can be cleared when you do the deletes anyway.

If you leave the DEF fluid in there, it will definitely crystallize over time. If you're doing the deletes and removing the tank, does it matter? That's up to you.

[Persian Whisperjet]

Here you go:

http://www.e90post.com/forums/showpo...&postcount=113

[atropine]

Thanks guys. I will just do that same thing- drain the 2 tanks via gravity and then fill them partially up with some windshield washer fluid. I am thinking of doing this about a week before I do the deletes- I have a 50-mile commute each way so I will put on about 500 miles this way. Hopefully the SCR metering unit will pump a little of the washer fluid through the pump and tubing so it doesn't crystallize in there. My goal is to leave the DEF tanks in place, partially filled with windshield washer fluid, so that someday when I eventually sell the car the next owner could return it to stock if they wanted. I'm sure that is unlikely, but it wouldn't take much extra effort to drain the tanks and fill partially with WW fluid.

[Owen81]

Keep in mind most washer fluid (in Canada anyways) contains alcohol or methanol which would probably do some damage to your SCR

[Torqu3]

Originally Posted by Owen81

Keep in mind most washer fluid (in Canada anyways) contains alcohol or methanol which would probably do some damage to your SCR

Considering people are using their SCR tanks for water/meth injection, I don't think that'll be a problem.

[aaddam2]

alcohol is better than DEF or Water...biggest issue with water would be pure water in any hoses, or small confined spaces where freezing would cause water to expand and wreck those components. i would say if you want to keep it 100 empty, drain DEF, Flush with water to purge out any residual DEF so no crystals, and then run rubbing alcohol (prob cheapest) through the DEF tank to purge out water and ensure it is bone dry.

Torqu3 i didnt forget about your pictures

[TDIwyse]

Since DEF freezes around +12F and has an expansion ratio similar to H2O (~7% vs ~9%), and a lot of us live in areas that get substantially colder than 12F ... I would expect the tanks/lines are designed to handle freezing fluid. I know I've had completely frozen DEF in my system before as I've parked overnight outside in -20F temps many times and didn't have any rupturing/breaking of tank/lines. Would be interested to hear if people have had problems with ruptures due to freezing/expansion.

[robnitro]

Forgive me if I missed it, but what's the problem with keeping the tanks empty?

(Of course after a flush with water to get out any def residue)

6.1 gallons of water total @ 8.34lb/gal is 50 lbs weight saved.

[335dFan]

Attached please find the service instruction from a few years back.

[Owen81]

Originally Posted by Torqu3

Considering people are using their SCR tanks for water/meth injection, I don't think that'll be a problem.

I was referring to the SCR converter in the exhaust. I don't think it would be a good idea to shoot highly flammable liquid into there if you want it to retain its function.

[duramax]

I pulled the plugs and nothing came out of either?? Any idea why? Waited 30 minutes and nothing but a drop.

[Owen81]

Maybe your vent is clogged with crystallized DEF fluid? This would vacuum lock the tanks

[duramax]

where is the vent, I never had an issue and just filled them up about three months ago when the light came on. I have since tuned everything out.

[vlad7777]

Originally Posted by atropine

So I have tried searching but am having a hard time finding the right info. I'm about ready to dive into the DPF/SCR deletes and install the ATM downpipe/exhaust/intercooler/intake. I already have the EGR block off installed. I would like to drain the DEF tanks and fill them with distilled water so if the next owner needs to return it to OEM they can. Is there a DIY for this process somewhere?

Where can I find information and parts for retrofitting 2012 BMW X5 E70 CIC with DPF/SCR deletes.
Any information would be appreciated, but best if there is a video and link to partd buy.
Thanks

[lnxguy]

Originally Posted by Owen81

I was referring to the SCR converter in the exhaust. I don't think it would be a good idea to shoot highly flammable liquid into there if you want it to retain its function.

No shit eh? lol

[robnitro]

Can't you just fill with water and then drain and leave the tanks empty? No need to worry about freezing then.