On Injector Failure and water

[rapidoxidationman]

My cousin (kind of a professional recreationalist gearhead) and I were talking about the failures of DMax injectors and all that goes with it (P0087 codes, fuel in oil, $5000 repair bills, etc). He presented the theory that is isn't so much the crummy, dry fuel that contributes to the death of these spendy bits of the engine as much as MOISTURE!

Rusty fuel lines - check
Water is more abrasive than fuel - check
Crappy water separation system built into these trucks - check

SO: I'm interested in the failure rate of injectors in relation to climate. Had your injectors fail? Do you live in a wet area (lots of rain/humidity/temperature changes causing condensation in the fuel tank)?
Do trucks in the southwest deserts have longer lived injectors than diesels in the northwet like the Oregon coast, for example?

What are the collective thoughts on installing a high quality water separation system in the fuel line as being even more important than extra filtration and a lift pump to extend the lives of the injectors and related components?

[dually2002]

I live in a humid environment in NW Florida not far from the Gulf. MY 02 still has the original injectors at a 101k but has never did long term hauling with it but fanatical about changing the fuel filter (Donaldson) at no more than 10k. Got truck with 25k on it and have always used fuel conditioner and cetane booster and been running a Kennedy tune for the past 5 years. I always had in the back of my mind that diesel fuel is not formulated as good as it could be for high pressure fuel systems and its ability to foam makes me think that without a lift pump the injectors are getting aerated fuel when temps.are high and fuel viscosity is lower. The fuel could be aerated to a point that the needed pressure cannot be achieved and is bypassed back to the tank. Do Ford and Dodge use lift pumps?

[More Power]

Correct me if I'm wrong, but my sense is that reported fuel line rust on the Duramax is more on the outside - under the fitting nut on each injector.

Internal rust due to moisture contamination of the fuel doesn't seem to be a problem, or we'd see it inside the DB/DS 6.2/6.5 pumps as well. It's not there in the pumps I've seen lately.

I do know that prior to the 2007 introduction of the ULSD, the fuel injection industry nearly panicked over the decline in lubricity. Here's some stuff I wrote about ULSD a few years ago...

Well ahead of the introduction of Ultra-Low Sulfur Diesel fuel, a new fuel lubricity standard was published in January of 2005 as defined by ASTM D-6079. The actual test for diesel fuel lubricity was established by both ASTM D-6079 and ISO 12156-1, which describes the High-Frequency Reciprocating Rig (HFRR) test method. In simple terms, the HFRR test rig is comprised of a small steel ball pressed against a steel plate with a 200g (~7 oz) down force, vibrated back and forth at 50 times per second with a stroke length of 1 mm for 75 minutes, and while bathed in heated 60 degree C diesel fuel. At the conclusion of the test, the wear scar is measured, which is then used to determine the fuel’s lubricity. Current Ultra-Low Sulfur Diesel fuel must, according to ASTM, meet the 520 micron max wear scar specification (or less) when using the HFRR test method. A consortium of DFIE (Diesel Fuel Injection Equipment) manufacturers have pushed for diesel fuel that produces an HFRR rating of 380 micron, but they didn’t get it.

In some states, the lubricity standards are being met by the addition of 1-3% bio-diesel. Fuel sold in some states is meeting the standards through the use of fuel treatments, which I tend to distrust. Let me explain.

Just like your engine’s rod and main bearings, “hydrodynamic lubrication” is important to help keep two closely rotating metal surfaces apart. The viscosity of the diesel fuel plays a role in determining the level of hydrodynamic lubrication. The second level of protection is called “boundary lubrication”. Should close-fitting components actually come into contact, boundary lubrication is there to prevent excessive wear. Many commercial diesel fuel lubricity additives are comprised of a polar group of chemistries (fatty acids and/or esters), which are attracted to metal to form a boundary layer between closely fitting metal components like those used in a diesel fuel injection system. A significant improvement in lubricity is possible with a miniscule concentration of just 10-parts per million to 250-ppm treatment (depending on which type of chemistry is used). 10-ppm is equal to just over 4 one hundredths of an ounce of lubricity additive per 34 gallons of diesel fuel.

This polar attraction process could be a concern to those who receive fuel that was treated at the refinery or otherwise stored for long periods in metal tanks. The various pumps, metal piping and storage tanks used in fuel distribution could reduce the amount of lubricity additive making its way into your truck's fuel tank. The best time for a fuel distributor to add a lubricity additive is while the ULSD is being transferred into your local fuel station's non-metallic fuel storage tank.

My question is, do Duramax injectors live longer when using an ASTM certified Bio-Diesel blend when compared to straight 100% petroleum ULSD?

I believe "wear" caused by low lubricity/low viscosity ULSD diesel fuel is what causes a P0087 (excessive fuel return flow), smoke at idle (ball seat erosion) and other related problems. Jim

[rapidoxidationman]

Would the metals of the storage tank/transfer equipment/fuel lines etc. not eventually reach a saturation point and no longer be able to absorb the additives? My knowledge of chemistry is pretty much nil, so the answer could very well be yes... Moot point for this diesel enthusiast anyway, as I add my own at each fillup (don't laugh, but I use the gray bottle Power Service, about 4-6 oz. each fill). It's worked for the several hundred thousand miles I've put on GM products and the '85 Benz is still pretty strong too.

Back to the topic at hand though: Climate related water in the fuel causing premature fuel system failure.

Is there a way to make a poll with regards to injector life vs. climate? My hypothesis is that trucks in dry, desert areas will tend to have fewer issues with injector replacement, related codes, and limp modes while the wetter, more humid climates will have more issues...

[DmaxMaverick]

I think you have a valid question, but there are other factors to consider. Without a control climate, your answers will be affected by the other climates considered, as well as other variables. For example, while the southwest is a dryer climate, it also has a much higher rate of airborne sub-micron silica (dust). This also enters the fuel system, and is only marginally controlled by filtration. This, in itself, is a much greater threat to the hydrodynamic lubrication quality than water. Water isn't a lubricant, by many definitions, but it is a lubricant, and a film barrier to some degree. Water's greater threat is its explosive nature under extreme pressure and/or heat, and its solvent ability, with a great enough quantity. Most water controlling additives, including alcohol, do well to keep this condition under control, by either demulsifying it to a level it can be contained and collected as a whole (prevent passage by the water barrier, filter media), or emulsified, allowing it to pass through the system in such small masses it's harmless. Water is present in all stages of fuel handling in varying degrees. It's my opinion that condensed water from climate humidity is minute by comparison. If water is entering the system via other means, such as rain, or driving in very wet conditions, it's an issue with the system integrity, and a problem that needs to be fixed. If you leave off the fuel cap and drive through a car wash or a rain storm, water is probably going to enter the system in larger quantities. This is not a fault of design. Other than that, the fuel system, by design, is intended to manage environmental incidental moisture, by filtration and elevated fuel temperature.

You can initiate a poll as an option of a new post. Give it a shot.

[Kennedy]

Air, dirt, water, and lack of lubricity all plague the Dmax fuel system. A lift pump takes care of the air and helps the filter(s) do a better job. Secondary filtration helps with the dirt and depending on the media type can guard against free water. A quality fuel additive will take care of the water and lubricity although my preference contradicts GM's position. Where GM wants to separate the water and use the filter as a "zone defense" (does not work in real life) I prefer to use an emulsifying additive and handle water one on one to get it safely gone.

[More Power]

It's likely that the fuel qualities of ULSD discussed here, as well as dirt, water, air and so on are all contributing factors in injector failures to one degree or another, and which vary between instances of injector failures. Or, it could be that the materials used in these injectors simply isn't up to the task of up to 29,000-psi operation over the long haul. It's a complicated puzzle without any clear-cut answers.

I do know that there are few aftermarket solutions, regarding any of the "fixes" proposed over the last dozen years, to lengthen the lifespan of these electronic high-pressure common rail injectors. If there was a clear-cut fix, that inventor/company would rake in millions. Unfortunately, many of the proposed fixes do very little, except to alarm truck owners and sell stuff.

That said, additional fuel filtration and fuel treatment can never be a bad idea unless the stuff the owner is using is crap or the way they're using it inadvertently creates a new set of potential problems.

GM wants to sell vehicles that don't create a warranty debacle. I believe GM also wants their vehicles to have a high re-sale value - whether in or out of warranty - build brand loyalty. Unfortunately, a $4500-$6500 injector replacement cost hurts the reputation for all current but out-of-warranty diesel pickups. You'd think that after producing tens of millions of these injectors, the replacement cost would come down or they could be made to meet owner expectations for longevity. Jim