This is a repeat of something I just posted in 'High Mileage Trucks' - a thread I started where I'm posting info I get from our CAA tow truck drivers (same as the US AAA).


This driver I spoke to this morning said they just heard back from GM [they have ~18 trucks all with Duramaxs all but one experiencing one or multiple instances of injector problems] and that after close analysis of this last failure they've found that the injector was blocked [not damaged, just clogged] by a tiny piece of paper they believe comes from the fuel filter.


I'm going to try and get a confirmation from someone in the CAA offices, but if this is true and turns out to be a source of injector issues, then pre OEM filters won't help. The only way to prevent this would be with a post OEM solution [or a better filter in the first place]


Wouldn't that be a strange twist if it wasn't the fuel at all but rather the OEM filter??


Edit - I should mention that GM has requested that the CAA change their filters monthly from this point on.Edited by: EnerMax

You can be sure we'll be watching this one. Thanks for the info.

Wouldn't changing them more often increase the chance manufacturing debris to be introduced into the system???? You would think at 22,000psi the paper would be forced though the nozzle. Just my $.02.

I don't think that we are looking at that kind of pressure at the fuel fitler itself (22,000 psi?).

I hope that paper is not actually that flakey corrosion we saw on the Head gasket RnR pictorial?

I can see it now ... a post OEM filter built specifically for filtering paper particles from the OEM filter. http://www.dieselplace.com/forum/smileys/Big Smile.gif

Assuming this isn't another flawed Racor filter, George M stated before, sharp metal and rust particles before the OEM fuel filter impacts the paper element. This may be the best reason to get ourselves filter magnets.

Another reason to run high quality ceramic filters......

Not to boubt what you say, but this sounds kinda fishy.I would not dare buy a fuel filter from the dealer because of price alone. I have worked in 3 major carriers shops and we used alot of the Napa filters made by Wix that sees fuel from all over. I feel it is a good filter and use the Rotella DFA additave;always fill the tank so if a problem arises it will be narrowed down to a particular station in the case of being a contamination issue. Just my thoughts an a heavily discussed issue. Esmo.

I'm skeptical that this would be "THE" biggest reason for the bulk of injector failures.

Unless there was some type of issue with filter media during a long production run cause Racor has been making and testing filters for a long long time and more than likely knows what holds up and what does not. Filter media breakdown would be a number one criteriea in media selection.

First they would have to find the clogging in multiple cases. Then they need to trace the material to the filter media.

Again... we'll just have to wait. Personally I think one injector going bad sets up a domino effect when a tech takes everything apart, not understanding the corrosion issues in the fuel feed lines. When time is an issue (flat rate) and money is to be made, things tend to get put together rather quickly. Edited by: hoot

Yea I agree. I bet it had something to do with a bad load of fuel maybe causing rust. I don't know, maybe the fleet stores their own diesel tanks and the water content went awry. Multiple injector failures on a truck isn't a surpise with what we've recently learned about corrosion and maintence procedures, multiple failures in a small truck fleet is very surprising.Edited by: Ray403Dmax

Anyone know how paper from the filter can get into the fuel to block an injector?

Anyone know how paper from the filter can get into the fuel to block an injector?

Very easily. The fuel goes through the "paper" filter. Possibly the filter paper fibers could become loose and let go on the clean side....

Water in diesel pools or collects in the tank of fuel, causing all sort of bad stuff, including microbial growth as well as rust. Rust and metal particles could detach moving into the filter paper media and over time break through. I was always concerned about dirt passing through the broken down media and never considered the paper could in turn break free. But I guess crazier things can happen.


I suppose the media break down it could also be caused by a chemical or additive. It's a clear path from the filter media's clean side to the injectors.

Regarding rust in our fuel tanks ... aren't the fuel tanks plastic?

You would think 23000 PSI would blow just about anything through?

Regarding rust in our fuel tanks ... aren't the fuel tanks plastic?


That's true, but fueling stations and fuel tankers have lots of metal.


It would be nice to hear George M again on this topic. IIRC, he advices additive usage as our fuel systems have metals within them that can also rust from water build-up.


I hope all is well with George.

These canadian AAA trucks probably spend most of their time idling; I know if I were in that cold of weather - the truck would be running and heater on full blast for my entire shift... I would find out how many hours they have on them before you draw any conclusions.

Someone else here mentioned that they use 300-350 hours running time as a ballpark for changing out the fuel filter. For these guys - this is probably once a month (which is what GM recommended).

I noticed on another board that a "hot-shot" guy had 230,000 miles on his truck before first injector issue -> he lived in florida. "CaptainMal" who ran around large trailers (extremely extreme service) - had problems at 130k miles; Maybe florida guy had straight #2, and CaptainMal got blended fuel in wintertime (with less lubricity).

I think that fuel lubricity is possibly the primary factor related to injector longevity (not filtration). Most on this board use FPPF total power - looking at lubricity test results on stanadyne's website - I am not sure the standard FPPF products don't do much to enhance the lubricity of fuel; It looks like they do sell other "... plus lubricity" products that would do much better in this regard.

I am running stanadyne's "lubricity formula" and will be running it year round - it is relatively inexpensive. (nothing in it to deal with water - so no emulsify versus demulsify arguments necessary). It states it add lubricity that is needed when running blended fuels or #1 , etc. This is definitely the case with these Canadian AAA trucks.

You previously said one of these trucks had used an additive and had no issues - which additive was used???

thanks,
jeff

I think that fuel lubricity is possibly the primary factor related to injector longevity (not filtration). Most on this board use FPPF total power - looking at lubricity test results on stanadyne's website - I am not sure the standard FPPF products don't do much to enhance the lubricity of fuel; It looks like they do sell other "... plus lubricity" products that would do much better in this regard


Just read the document you mention on Stanadyne's website. Unfortunately the test results are for Polar Power, not Total Power. The document that I read is at this link:


http://www.stanadyne.com/dsg/showfile.asp?id=1156


Are we talking the same document?


I went to the FPPF website and looked up Polar Power. It does not mention anything about a lubricity additive being part of the product. So the test results are correct from that respect. On the other hand, Total Power does mention a lubricity additive is included. It also mentions that Total Power meets the ASTM BOCLE spec for lubricitity (now we need to figure out what that is).


http://www.fppf.com/catDieselPT.html


From what I have read over the last year and a half, both lubricity of the fuel and the particle level in the fuel contribute to wear.Edited by: OC_DMAX

Thanks...


I agree with what you say - fuel quality (lubricity + cleanliness). Conversations here tend to focus on cleanliness. There are different ASTM BOCLE tests - as long as it meets some measure it's good...


You might find something here on wear tests..


http://www.chevron.com/prodserv/fuels/bulletin/diesel/L1_toc_fs.htmt


For what it's worth - I asked captainmal a couple of questions about how he used his truck and additives, etc. He ran howes - it didn't perform well in stanadyne test that you posted reference to.


jeff

Yes, our fuel tanks our not metal but every other tank, valve, pump that the diesel fuel goes through before reaching our fuel tank IS steel. I have found that a major contaminant portion is indeed ferrous in both raw and rust form. Thus, as mentioned previously, that finely sharpened piece of shrapnel moving at high rate provides a perfect cutting tool for a cellulose fuel filter element.
And yes, lubricity enhancement is a very important aspect for pump/injector life extension. Primrose (and other quality additives, I am certain) provides the highest level of measurable increase in lubricity at normal treat levels. (both Primrose 405 and 409 Winter contain lubricity enhancement).

Do service stations filter the fuel or do they pump it straight out of the tank?

All of our bulk fuel tanks have filters on them.
Over the years we have run a lot of fuel thru tractors, pickups and trucks and very seldom have we seen injector failure. Have had them worn out with well over 10,000 hrs on them.

Some Service stations and truck stops do filter, most do not. Of the ones that do filter, filtration is totally indadequate. (10 micron nominal which means little or no 7 micron filtration efficiency)
And yes, tractors/pickups and trucks USED to seldom have injector problems; however, in the past several years we have transitioned from 3000 psi injector and fuel system pressures to 20,000 to 30,000 psi systems which require jet fuel level cleanliness for long life and durability.
Dutch, you seem to have come onto this site just recently as there are literally volumes of information that have been shared on the subject of fuel cleanliness, including several articles, ASTM technical papers and, in my case, about 6 inches of scar tissue on my derriere from the astronomical end line cost of dirty fuel on modern fuel injections systems.
George Morrison

Dmax Lover;


If you want to evaluate the "state of our diesel fuel" with respect to the HPCR system and lubricity, reference the document at the link below. It is a presentation done by Bosch to the CARB (California Air Resources Board). I think you will find it interesting. I have also included a similar presetation by Cheveron (similar to Bosch)


The conclusion on slide 23 of the Bosch presentation is something everyone on this forum should read. Supports pretty much what George has been talking about for several years now. The keywords being " All high-pressure fuel-lubricated injection systems are exceedingly lubricity-sensitive and require clean fuels (no free water and/or contamination)".


http://www.arb.ca.gov/fuels/gasoline/meeting/2003/


Once in this folder, look for the following PDF documents, right click and download to your computers to read:


022003bosch.pdf


022003chevron.pdf





Later,


AlanEdited by: OC_DMAX

Alan,
Thank you so much for posting the CARB Bosch information. I have to smile reading the study in that it is, of course, superb work. However, to not have any quanifiable measure, or standard, with respect to contaminant levels in the test fuels is amazing.
Hydraulic system component life is directly propotional to dirt levels; this is with exactly the same lubricity levels. However, I have seen component life increased with heavily additized fluids (increased anti wear, etc.) but it was masking the root problem.. I am wondering if Bosch is not at least partially reporting a similar result. Granted, lubricity in diesel fuel is a most important component but if the fuel is not clean, all the lubricity enhancement in the world will not cure the cause of the wear..
It may well disguise it, however..

George

George, Thank you.

Yes, I am pretty new to these boards although I have been reading for a while.

I work on a large farming operation where we run anywhere from brand new (2003) tractors to late 90's models. The latest use common rail fuel injection and have anywhere from 1000 to 6000 hrs on them.
Out of 8 of the newest we've had 1 injector go out. It went out pretty early in its life, well before 1000 hrs.
But, these tractors have 2 fuel filters on them and some have an added water seperation filter.
1 of these tractor manufacturers recommends changing fuel filters every 250 hrs!

I guess what I'm trying to say is that GM needs to get with the program and put a decent filtration system on these trucks.
They've got a good product here but it does need some tweaking.
I still run the stock filter but then we filter pretty good when we fill up.
We now have 4 DM's and 3 PS's, 2 of them the 6.0.
We will see how we get along in the next year with them.
It was just the boss and me running the diesels before, now several of the other employees run them too.

George,


It looks as if the agenda for that particular CARB meeting centered on the forumulation of fuels and the addition of additives to increase lubricity. So the presentations were developed along those lines. I hear what you are saying about fixing one problem while the root cause is still not addressed. I have to believe Bosch has the data you mention.


I believe the one bullet in the Bosch chart really summarizes it the best for us "end users" of a product; Keep it as clean as possible, no free water and make sure the lubricity is adequate. I think a lot of people on these forums are accomplising that by supplemental filtering and using additives. Can't do any more.

Alan,
Yes, you are 100% correct in that we on this board have indeed addressed all of the issues relative to fuel system life maximization. My frustration comes from the almost complete lack of acknowledgement by fuel system and diesel engine manufacturers regarding the issues.
They design and manufacture beautiful diesel systems which are very fuel efficient and provide superb emissions, only to immediately begin to degrade with the first diesel fuel used.. In "the real world", however, I must keep reminding myself that the manufacturer's primary objective is to make it through warranty with minimal cost. Which is exactly what we almost have..
I must admit that I do see a similar situation in industrial and large construction/mining hydraulics. A manufacturer will sell a $2 million dollar hydraulic excavator equipped with a 21/19/17 oil filtration system which should be a 15/13/10 filtration system. The unit's pumps, servo valves, motors will make it through warranty just fine, then the profit center begins for the manufacturer with the replacement of $38,000 pumps like clockwork..
Ahhhh, free enterprise at work.. The hydraulic manufacturers know full well what they are doing; it is part of their business plan..
But indeed, it IS at work on this site... Again, it simply amazes me in the level of discussion that takes place here. I am most certain some posts are copied and discussed behind closed doors at the above manufacturing plants.

What doesn't make sense is the reputation GM has at stake here and the thought of them intentionally setting up the Dmax to produce off warranty parts sales.

We know it's the rule with front end (steering gear) and so on but the consumer costs are reasonable there.

When you throw 1000's of dollars of off warranty costs at the consumer where the money comes directly out of the end users pocket, you are risking a future backlash like no other.

Corporations have ways of absorbing these somewhat known maintenance costs often by passing it on to the other corporate customers. We as individuals cannot afford those kinds of costs.

Looking towards the future, my next vehicle may not be a diesel. I'm not sure it's worth the costs.... especially if (big if) we can't get a couple hundred thousand miles without putting out an extra few thousand on top of the $5000+ premium we start with.

I must add that performance mods really leaves all of us using them without an arguement but we are watching the un-modified.... of which are the majority, closely.

We need as much fleet info as we can get! Edited by: hoot

I wish we could ge to the bottom of this. There are 3 to 4 threads going simutanously about fuel issues. I suggested one standard location? From what I have gatherd water,air,metal and other contaminets all play a role in logjevity. I think the additives are simple to figure out but the filtering is a whole nother story. I think it is complicated because there are loyalist to people like Nick, George and JK. They deserve this loyalty and sell good products. It does not mean it is the absolute best for our Dmaxes. If paper is bad then why not ceramic? If the best set up is a heavy duty 10 mic that stops all big stuff with out letting any metal pass then why not? Follow this with a very fine high qulity 2 mic. at the stock head. Throw a true water separator in the middle of all of that. Why not. Throw some magnets in there for good measure,unless this changes polarity and causes extra corrosion? We as the consumer drive what the vendors are selling,whether we like it or not! Please lets put our hearts to the side and get real. I do not care if this means one product will become the front runner. Maybe all vendors will start selling the same kit and there will be a price war? Good for us, the consumer. Do not think I am not greatfull for all of the time and energy vendors have put into. saving our trucks. I do appreciate it, and understand we could of never gathered this amount of knowledge without there diligence.

How about an injection system design that's a little more forgiving?

That would be nice. I could probally put a filter system on my truck that turns diesel into pure rocket fuel before auto manufactures will do that. Unless the new Tundramax has something up it's sleeve?

Unfortunately a "forgiving" systen is not synonymous with high performance and low exhaust emissions. With these modern day requirements, ultra high pressure, electronically actuated, computer driven fuel systems are going to become even more sophisticated as time goes on..
Fortunately the work being done on this site is enabling us to keep abreast of the problems.
George

Mybe the injectors need to be more expensive, meaning tougher materials. Pay up front for durability.

If I pay another 5k$ at 100k to keep my truck alive for another 100k that is really not all that bad. 1k$ per/year in my case. OK? My real question is "If I have an injector problem what can I do to minimize the side effects and insure a correct repair?"

Update - spoke to the same CAA driver who told me it was paper in the injectors. He now tells me that GM is covering the extra cost for the two new trucks on the fleet to change their fuel filters monthly. All existing trucks in the fleet have had injector problems. My life is too busy and I have NOT been able to confirm this with anyone in the CAA offices (although his story aligns with what I've heard from other drivers in the fleet). I just noticed another post where someone claims that GM is stating issues about silica or something like that in the diesel that has forced them to change their filter servicing from 10K - 15K down to 6K?


I can't confirm this stuff, but I'm thinking of accelerating my filter changes... you'd think I'd find time to talk to someone at CAA to confirm but life has a funny way of keeping you from getting to things.....