Answers to Your Questions about Biodiesel
Detroit Diesel and Biodiesel
We've weighed the pros and cons of biodiesel, and Detroit Diesel supports the use of biodiesel blends. That said, the biodiesel industry is young, and there are a number of issues owners and fleets should know. Below, we've collected answers to some common questions about biodiesel.
Will using B5 biodiesel void my Detroit Diesel engine warranty?
If a Detroit Diesel component fails because you used fuel (not just biodiesel) that doesn't measure up to industry standards, the damage will not be covered by your warranty.
You'll note in your warranty where it says, "Performance of required maintenance and use of proper fuel, oil, lubricants, and coolants are the responsibility of the owner."
In other words, filling your tanks with a homebrewed biodiesel blend could very well void your warranty.
For full details, see the engine operator's guide for your engine.
What kind of issues might I run into using biodiesel?
Over the past few years, we've seen some common problems in using biodiesel in Detroit Diesel engines.
- Fuel Filter Plugging
- Cold Flow Performance
- Water and Microbial Contamination
- Fuel Injection System Failures
- Incompatibility with Materials in the Fuel System
Fuel Filter Plugging
The most common problem experience with biodiesel blends is premature fuel filter plugging. There are many reasons why biodiesel blends may plug fuel filters:
- Poor cold flow properties
- Biodiesel solvency
- Poor fuel quality such as microbial growth, glycerin contamination and precipitates above the cloud point
Cold Flow Performance
Blending with biodiesel reduces a fuel's cold flow properties. Talk to your biodiesel supplier to make sure it is appropriate for your weather conditions.
Water and Microbial Contamination
Biodiesel blends are more sensitive to water contamination and microbial growth in bulk storage tanks. It's quite likely you'll get water passing through the engine, since biodiesel lowers the effectiveness of water coalescing filters. Water may also increase fuel system corrosion.
Microbes will plug fuel filters, meaning fuel storage tanks may need routine treatment with a biocide.
Fuel Injector System Failure
Injector lacquering, deposits and corrosion are all more likely due to biodiesel instability and water contamination. Biodiesel contaminated with sodium during manufacturing has been proven to rapidly foul all six fuel injectors. Symptoms such as nozzle sticking, reduced power from flow restriction or leaking fuel all point to a biodiesel problem.
Also, since injection pressures are higher with biodiesel blends, it puts more stress on the fuel system. That can lead to problems with your injectors, transfer tubes, high pressure fuel lines and potentially the rocker shaft and arm (for unit injectors). It's difficult to nail down the exact cause, and often the part that failed is blamed when, in fact, the additional pressure from the biodiesel is the culprit.
Incompatibility with Materials in the Fuel System
Biodiesel can slowly eat away at older gasket, hose and seal materials made of nitrile, NBR, HNBR or other older seal materials, eventually causing a fuel leak. Fuel systems made today use higher quality materials.
Biodiesel blend users must avoid allowing biodiesel to contact with zinc, copper, bronze and lead as they cause a chemical reaction that breaks down the fuel. In other words, it increases the likelihood of fuel filter plugging, and fuel system lacquering, deposits and corrosion.
Is biodiesel OK to use with my EPA 2007 Aftertreatment System?
High quality biodiesel blends that meet industry standards should not affect the performance of the EPA07 aftertreatment system. So yes.
However, as explained above, biodiesel blends is known to plug fuel filters. In EPA 2007 engines, the first sign of plugged fuel filters is usually low fuel pressure to the hydrocarbon doser injector, which may prevent active regeneration, and thus trigger the Check Engine light.
And like the fuel injection system, the hydrocarbon doser injector is also susceptible to a higher potential for lacquer, deposits and corrosion. Lacquer and deposits can be expected with higher biodiesel blends, especially if the biodiesel does not meet industry standards.
Does Detroit Diesel certify its engines with biodiesel?
No. Detroit Diesel does not certify its engines with biodiesel blends. The EPA requires certification be conducted with a well-defined ultra low sulfur diesel fuel that contains no biodiesel. So it is the responsibility of the end user to ensure the fuel used is registered with the EPA and legal.
However, numerous studies have been published showing that biodiesel blends reduce most emissions. And as the young biodiesel industry continues to grow and refine its fuels, Detroit Diesel will support our customers who want to do what they can for the environment.
