First off, let it be known that I am a huge proponent of Bio Fuels. Part of the reason I bought a diesel.

I bought my truck in Nov. 2009 with 41k (2007 LBZ) and instantly started using biodiesel. Kept an extra fuel filter in the cab as warned, but never had a problem. B50 in the winter, and B99 March to November. SeQuential Fuels is a huge bio producer in Oregon, and I seem to trust their performance over a small co-op kind of production.

I'm at 56k now, just put a new fuel filter on 700 miles ago. So a couple weeks ago I put in a tank of B99, the first 99 of the season. Temps here are 45-55F, and my truck instantly ran shitty. More than 25% throttle made the P0087 code throw. I put a vacuum gauge on the port it ran 20" Hg. 3" is normal.

Edit: for those of you that don't know- P0087 is "low fuel rail pressure" and the Duramax doesn't have a lift pump. The fuel is vacuumed from the tank by the injector pump itself. There's a port in between the injector pump and the fuel filter to measure vacuum. 3" Hg (mercury) is normal. As your fuel filter gets clogged (or other obstruction), it takes more force for your injector pump to pull fuel from the tank and through the filter.

Changed the filter, filled with dino diesel, and all is fine.

I cut open the fuel filter expecting to see a handful of sludge that somehow got left over from the first 41k of dirty diesel from the previous owner. I opened it up to find a pretty clean filter (I think?). But I could barely pour out the diesel. It had the viscosity of hot motor oil. I had to squeeze it to get the fuel to drip out. I actually saved the fuel contents of the filter and used it as fire starter camping this weekend. I was amazed that it rolled down the firewood like motor oil would. Still 40's temp F.

So what happened?
1. is this a dirty filter?
2. does B99 gel at 49F?
3. did I just get a bad tank of Biodiesel?
4. does biofuel break down the fuel filter elements?
5. is this just thick biodiesel?

I want to be a good human and use waste oil- or anything not from the middle East! but at $42/pop, it doesn't make sense to keep buying fuel filters.

https://lh6.googleusercontent.com/_uyOUdU1hnxI/TZD5qZE42bI/AAAAAAAAR_g/BdxioWjVDvA/s512/IMG_3977.JPG
https://lh3.googleusercontent.com/_uyOUdU1hnxI/TZD5qSUp4PI/AAAAAAAAR_k/9XCBk_ZaqoI/s640/IMG_3978.JPG
https://lh5.googleusercontent.com/_uyOUdU1hnxI/TZD5qU_H7fI/AAAAAAAAR_o/bSYay2aVdpk/s640/IMG_3976.JPG
This big slice ^ was from my knife looking inside the filter

Your story makes perfect sense. That looks like a new coalescing fuel filter and they are VERY bio sensitive when you get in the 40-50 degree range. Even tho' the bio looks fine it is too viscous to pass through that filter in cooler temps. I've gone through the same thing...trust me.... Feedstock that the bio-diesel was made from makes a slight difference as well regarding CFPP (cold filter plug point). You could have heated the fuel and it would have passed right through the filter. I know this because I have a 2 micron filter on my bio-diesel reactor fuel pump. When I filter cold fuel (under 50F) the pump will slow down to what seems like 1 or 2 gph. When I heat the fuel up it pumps it out really fast. Keep dino diesel in it until the temps are gonna stay 60+. A cool night in the 50's with day time temps in the 60's-70's will be fine too.

Thanks. I guess that's good news. Except that I cut up a $42 filter for naught. Maybe I'll just do 50% B99 and 50% Dino until it gets warmer.

Thanks for the perspective.

-KM

I also am with you guys. The bio was to cold to flow. Feedstock plays an important part of what temp the bio gells.
I'd imagine if you took the "thick motor oil" bio and put it in a jar and in the house.. it would flow just fine after warming up.
Personally I ususaly run 50% or less... but that is because I only make about 100 gal a month. I have tun HIGH bio, but not in winter.
Good luck.
Wags

Well this is interesting because I live in the Portland area and have been running B100 since our last cold spell around mid February. I run B100 except when the temps get below 30 and I then blend to about B75. I've been doing this for the last 5 years. I also make my own and not buy bio. As for the filters, I have noticed a difference between the white metal casing filters vs. the black plastic casing filters. The newer black plastic seems to flow better. To me it sounds like you got a bad batch that may have unprocessed oil in it, causing it to be thick and not flow.

I believe metal vs plastic plays a part as well. For some reason the metal seems like it gets colder. Where/which filters are plastic casing Rockin?

I've been buying my filters from fleet filter by the case. Fleet Filter sells Napa Gold which are the same as Wix. Here is a quick pic of the two different filters (upside down to read numbers).

The white one is the metal casing (3910) and the black one is plastic (3960)

Thanks Rockin C Racing. I've been reading a lot of your posts about making biofuel. It seems like I was using B99 during other cold spells and not having a problem.

I still have a small sample of the fuel in question. Is there a shade tree mechanic way of testing viscosity? The one thing that really threw me during this discovery process was that I couldn't pour the diesel out of the filter. Once I cut it open I had to wring out the filter element like a sponge. (well, the first 1/2 of the filter contents came out when I dropped the filter on the frame rail in the engine compartment. D'oh!).

I've been having the same problem for years on my 2007 LBZ. I make my own biodiesel so I know what kind of quality it is. I run the same biodiesel in 3 VW TDIs with zero issues in the winter (of course I am blending with petro diesel or kerosene). My truck will throw the 0087 code as well if the temps start to get in the 30s or below. I've went through numerous filters over the years and it has cost me a lot in filters. This past winter, I pretty much ran all dino diesel to prevent this from happening. I'm glad you started this thread because I know I am not the only one with this issue. I've tried the AC Delco metal fuel filter and have tried a lot of the newer plastic Wix filters (the same ones that Rockin C Racing is using) and have experienced problems with all of them. I've been doing a lot of research and I've been thinking about changing my fuel filter out to the Nicktane Billet Aluminum OEM Filter Adapter (http://nicktane.com/osc/product_info.php?products_id=51) with the CAT 2 micron filter. From what I've been reading, this filter will flow biodiesel better and perform better in the cold vs the OEM fuel filter. I also though about adding a Kennedy Diesel lift pump to help push the fuel through the filter. Let me know your thoughts on this.

You guys running Bio in high % need to consider using a more specialized filter due to the aggressive solvent action. Cim-Tek makes filters that can handle the agressive solvent action. They have 1, 2, 5, 10, 30 micron filters in various sizes but the ones most favorable for our usage would be a 1-12 thread. These filters fall into the "Bio-Tek" part of Cim-Tek's filter lineup.

http://cimtek.dirxion.com/WebProject.asp?BookCode=cim08flx&SectionIndex=0&PageIndex=52#

I run all my fuel through a 1 micron bag filter before dumping it into my truck. Plus i have two lift pumps. I got my filters through fleetfilter and when it comes time to change the filter, I'll cut it open and let you guys know.

All of my fuel gets run through the Cim-Tek hydro-glass 2 micron twice before seeing my fuel tank. I'm looking at 12v fuel filter heaters. They wrap around it like a sock. I can't seem to find one small enough for the airdog filters (3"). I've found a heated fuel/water separator that I'm researching.

I've been doing a lot of research and I've been thinking about changing my fuel filter out to the Nicktane Billet Aluminum OEM Filter Adapter (http://nicktane.com/osc/product_info.php?products_id=51) with the CAT 2 micron filter. From what I've been reading, this filter will flow biodiesel better and perform better in the cold vs the OEM fuel filter. I also though about adding a Kennedy Diesel lift pump to help push the fuel through the filter. Let me know your thoughts on this.
I looked at the same thing. If you're going to do it, save yourself $150 and just buy a WIX base (24770) $22 and either the CAT filter (1R-0749) or the WIX equivalent (33674) $12. Then some fuel hose (make sure it's 30R7 or 30R9). I spent some time looking up numbers for this stuff, and NAPA sells the base too but it's not listed as a fuel filter but as a hydraulic fluid filter.

There's an exhaustive (52 pages) thread here that shows how to do it, and several examples of guys that have done it different ways.
http://www.dieselplace.com/forum/showthread.php?t=68874
If you don't want to read all 50+ pages, read the first few, then page 50 has a really clean install with pictures and part numbers.

I thought this would be a great supplement to any diesel truck and lets you pre-filter all your fuel with a much bigger (and cheaper) filter. I was thinking that I'd rather clog $12 filters over and over than my $42 OEM filters.

The problem is more and better filtering won't help thick biodiesel get through the OEM filter. And until my warranty is done, I'm not going to remove the OEM filter. I can only think that applying heat to the tank/lines/filters would be the answer. I'm sure a lift pump would help too, but in my opinion, that's not really fixing the problem, it's adding another element to counteract the problem.

I'm going to add another filter to my truck fuel line down by the tank. I'm going to order it from fleet filters along with some WIX filters for the OEM spot. I'm also just going to mix in 25-50% petro diesel until the weather gets into the 60's (June? we've had 26 days with rain here in PDX).

Thanks for the smart and helpful posts here gentlemen.

-Kevin

Oh, whoops. That's a different Nictane set up than what I thought you were suggesting. That one is damn cool. I thought you were linking us to the under-truck set-up for $209
http://nicktane.com/osc/product_info.php?cPath=22_21&products_id=28

So is GM going to have a Warranty problem if you have injector (or anything) problems and you're not using a GM filter?

I think they understand common sense and also understand that the filter they chose for the LB7 was crap and somewhat to blame for all the injector problems. That aside, I can see them looking for any excuse to deny a claim including not using a GM approved fuel filter?

Am I being too conservative? Too paranoid? It just seems like GM will get out of any claim with the slightest bit of footing.

-Kevin

Ok, I'm having a conversation with myself now :) I guess a guy could throw his stock filter on for a trip to the dealer.

Doesn't this $99 adapter bypass the WIF (water in fuel) sensor?

Doesn't this $99 adapter bypass the WIF (water in fuel) sensor?
Yes, the adapter does eliminate the WIF sensor. You could easily switch back to the OEM filter setup if you needed to go to the dealer. From my understanding, the stock OEM filters do not trap much, if any water anyhow. Supposedly the CAT filters hold a decent amount of water without the need of having a WIF sensor. The biodiesel that I make should be practically free of water in it so that's not an issue with me. I realize I cannot run B100 in the winter time when it's 20 degrees outside and not have any issues. I just would like to run a blend of biodiesel/kerosene and not worry about the filters clogging up so much and throwing the 0087 code and me having to replace the filter.