[daytonadave]

Hello forum members, I'm new to this community so please bear with me as I'm sure to commit inadvertent faux pas. My d was purchased this past summer with 57k on the clock. At 69k I cleaned out the carbon. It seems a little h2o in the egr valve may help keep it clean. I don't care about the environment and don't mind adding pollutants to it. I do care about my awesome car and want to keep it looking cool. With that in mind, I've been thinking of using the def tank for water storage. Anyone ever done this or have any thoughts / ideas ? Any and all comments appreciated. Thanks, Dave

[daytonadave]

I was totally on board with gutting the whole egr system but my diesel guy (whom I REALLY trust), wants to leave it mostly intact.

[QUIKDZL]

Welcome, Dave. You'll find mountains of discussion on here about eliminating/blocking the EGR, removing the DPF (which also includes a DOC) and replacing it with a custom-made downpipe, and defeating the SCR. This is commonly referred to as the alphabet delete.

The acronyms stand for Exhaust Gas Recirculation, Diesel Oxidation Catalyst, Diesel Particulate Filter, and Selective Catalytic Reduction (this is what the urea, or Diesel Exhaust Fluid (DEF) feeds into).

I'm preparing to add water/meth injection now and have my car dyno-tuned by BPC in Raleigh. I tend to agree with your "Diesel Guy" so my tune will not include the alphabet delete. My rationale is that the car is a very refined automobile and I want it to stay that way. Most of my driving is highway commuting, but I do enjoy spiritied driving, occasional burnouts, drifting, etc. whenever the opportunity arises. For my purposes, the DPF and SCR do not limit my fun as, in my opinion, they are not overly restrictive. I like that the DPF prevents soot blowing out of the exhaust. The EGR, however, deserves some attention.

The purpose of EGR is to lower combustion temperatures to reduce NOx emissions. To do this, it feeds sooty exhaust into the intake where, coincidently, the crankcase vent is also feeding an oily mist. These combine to make creosote that clogs up the intake. If you read about how the SCR works, you'll find that this system is more effective than the EGR at eliminating NOx. So why do we have both?

It turns out that the SCR needs to get to a pretty elevated temperature to work properly and, unless you're really driving hard (which we usually cannot do), our exhaust temperatures are very low. Short trips usually do not even involve the SCR system. Also because of our low exhaust temperatures, our cars tend to warm up slowly. To make our driving experience more ultimate, BMW added an EGR cooler to preheat engine coolant (and further reduce combustion temperatures) and an electric ceramic heater in the air handling unit so we get heat much quicker than expected.

I'm having my tuner leave the EGR working as designed up to a coolant temperature of 150F, and then keeping it closed unless exhaust gas temperatures (EGTs) get dangerously high. I am also installing an oil catch can in the crankcase ventilation line to capture the oily tar and prevent it entering the intake, and a progressive water/meth injection system to clean my intake tract while giving a nice boost in power. DOC/DPF and SCR will stay intact and work as designed.

My car will still be one that my wife will enjoy riding in, and I should have about 340 hp and 540 ft-lbs at the wheels for entertainment...and still get over 40 mpg on the highway!

[daytonadave]

This sounds exactly like my "diesel guy's " plan. With the exception of a tune, we haven't discussed that, yet. My computer engineering major, son is researching defeating the codes associated with the def tank. I suppose using the already existing tank for H2o/meth injection may prove to be too much of a pita, but hope springs eternal.

[Nadir Point]

I have my 2-stage water-meth system set to use about a gallon of w/m per tank of fuel, so I need to re-fill the 2-gal tank mounted in the trunk at least every other fill-up. I expect to adapt the DEF tanks for this purpose at some point after I get around to installing a down-pipe and having the emissions coded out of the ECU.

[daytonadave]

I like the idea of water steam cleaning and meth bringing the extra kick. I'm trying to not get too crazy modding. I had way too much fun and spent way too much money on the 08 Bullitt that's now gone. This damn internet thingy is going to cause another divorce if I'm not careful. (the LSD is VERY tempting !)

[Thecastle]

Originally Posted by QUIKDZL

W
I'm having my tuner leave the EGR working as designed up to a coolant temperature of 150F, and then keeping it closed unless exhaust gas temperatures (EGTs) get dangerously high. I am also installing an oil catch can in the crankcase ventilation line to capture the oily tar and prevent it entering the intake, and a progressive water/meth injection system to clean my intake tract while giving a nice boost in power. DOC/DPF and SCR will stay intact and work as designed.

Its an interesting approach to EGR. Just a personal anecdote, when I installed the EGR block kit on my 335d, it noticeably reduced idle quality on my car. The car was noticeably nosier and sounds like I'm sitting in a diesel pickup, and rougher running at idle. Basically, it really reduced mine and others perceived refinement. I have since removed it for repairs, and boom car is running quite again. I suppose tuners can address the timing changes and other downsides of the egr block on idle quality.

So the thought of leaving the EGRs benefits intact, while minimizing its downsides sounds interesting to me. I too plan to install a catch can here shortly, already assembled the parts.

I want my car to be as refined as it is now and I too plan to run with my DPF/DOC for smell reasons and a lack of soot (I have a white car), and leave the SCR in place. I want more power without a loss of refinement.

[daytonadave]

I installed a catch can on my mustang and never really thought it was worth the effort. Does the 335d catch can actually help ? How often does it require emptying ?

[QUIKDZL]

Haven't installed mine yet...hopefully this weekend. From what I've gleaned on this forum, expect to empty it at every oil change.

As for effectiveness, I expect it to make a huge diference. Gasoline exhaust has very little soot, so the oily mist from the crankcase mixed with it is not such a big deal. Diesel exhaust is very sooty, and there is even more oily/sooty blowby in the crankcase because of the much higher compression pressures. When these get mixed in the intake, creosote (carbon build-up) forms on everything it touches.

[davegris]

Has anyone gone far enough to know if an immediate post-CBU cleaning water/meth injection kit is effective enough to keep the intake clean?

[Dazza335iC]

Originally Posted by davegris

Has anyone gone far enough to know if an immediate post-CBU cleaning water/meth injection kit is effective enough to keep the intake clean?

I'd like to know the answer to this too.

[gavronm]

Originally Posted by Bob@BPC

It is, next time we have one of our customers in with the meth kit installed and a cbu cleaning, I'll post some pics of the intake

Is that going to be someone that also has an EGR block?

Refining the original question a bit further:

Is a post-CBU water/meth kit on a vehicle with an otherwise stock intake (no EGR block and no catch can) sufficient to prevent CBU?

[daytonadave]

Excellent question. My guy thinks this is the answer. I'm going forward with using the def tank. My son seems to think the tank sensors can stay in place and remain active. He hasn't addressed any related sensors (if any) on the exhaust end of the def system. They would obviously have to be defeated , if they exist.

[Nadir Point]

The throttle plate, downstream from my larger w/m injector was spotless last time I checked - not the case before CBU cleaning and w/m.

[QUIKDZL]

Originally Posted by gavronm

Is that going to be someone that also has an EGR block?

Refining the original question a bit further:

Is a post-CBU water/meth kit on a vehicle with an otherwise stock intake (no EGR block and no catch can) sufficient to prevent CBU?

Refining it further still...will water/meth injection (along with a catch can and EGR defeat) clean up an intake with 96,000 miles that has never had any CBU issues or cleaning? (reverse the aging process?)

[daytonadave]

After seeing the buildup in my car, I can't imagine anything cleaning it without disassembly.

[Nadir Point]

Originally Posted by daytonadave

After seeing the buildup in my car, I can't imagine anything cleaning it without disassembly.

I'm inclined to go along with this.

It would seem more difficult to clean once dirty, than keep it clean to start with.

[TDIwyse]

Originally Posted by QUIKDZL

Refining it further still...will water/meth injection (along with a catch can and EGR defeat) clean up an intake with 96,000 miles that has never had any CBU issues or cleaning? (reverse the aging process?)

This may interest you:

http://www.e90post.com/forums/showth...4#post15652364

[Dazza335iC]

^good post, thanks for linking

[daytonadave]

Ditto

[GaryE30]

Originally Posted by Bob@BPC

Gotcha, a lot of guys like to use the EGR for faster engine warm ups during winter time. Then adjust the duty cycle of the EGR in the tune.

Oh I like this idea. Is this something you offer on your tunes? Also, would you recommend a water/meth injection if the EGR plates are removed in order to dial back CBU?

[Dazza335iC]

What kits are people using for their meth injection? JBD says their kits do not work on the N57.