Information on Diesel Fuel Requirements - Service Engine Soon (SES) Indicator ON, Loss of Power, Filter Life Percentage Low as a Result of Fuel Filter Plugged/Incorrect Fuel Grade
| Subject: | Information on Diesel Fuel Requirements -- Service Engine Soon (SES) Indicator ON, Loss of Power, Filter Life Percentage Low as a Result of Fuel Filter Plugged/Incorrect Fuel Grade |
| Models: | 2001-2008 Chevrolet Express, Silverado |
| 2001-2008 GMC Savana, Sierra |
| with 6.6L Duramax™ Diesel Engine (VINs 1, 2, D, 6 -- RPOs LB7, LLY, LB7, LMM) |
| Attention: | This bulletin indicates a fuel quality concern that is NOT covered under the new vehicle warranty. If a vehicle exhibits this condition due to poor fuel quality issues, please give a copy of this bulletin to the customer. You should also review the fuel requirements below so that the customer will have an understanding of the proper fuels available. |
This bulletin is being issued to inform dealers of the proper diesel fuel use requirements.
If vehicle concerns related to low rail pressure are experienced and if the Filter Life Percentage is low and/or the DTC indicates a plugged filter, a restricted fuel filter is the most likely cause or contributor to the condition. Filter/fuel supply restriction should be confirmed by measuring the vacuum at the schrader valve/service port. Vacuum readings of 6 in Hg or greater at idle indicate a restricted filter which is in need of service and may be the root cause or a contributor to the conditions being experienced. When the filter is changed and vacuum readings are reduced to a normal range of 2-3 in-Hg, fuel filter restriction cause is confirmed.
If the fuel filter is found restricted before its expected replacement interval, the cause may be use of contaminated/dirty fuel, improper fuel, or out of specification fuel. Fuel removed from the filter, lines or tank that is not clear and bright in color (clouded) confirm fuel quality concerns. When concerns are encountered in cold operation, the fuel should be inspected in a cold condition.
If the filter can is removed (using a suitable filter cutter), the filter pleat block may be inspected for indications of possible causes of premature plugging. A pleat block with the presence of deposits on the walls and bottom of the filter may indicate use of contaminated or degraded fuel or a filter that has been run significantly beyond its service interval. The presence of significant sediment and/or rust in the can are also signs of the presence of excessive water or contamination. A "slimy" coating on the pleat block filter may indicate the use of an out of specification biodiesel or unapproved bio-fuel (raw vegetable oil, cooking oil, unprocessed oils, etc.).
| • | Diesel fuel containing biodiesel in concentrations greater than 5% (B5) is NOT allowable and may contribute to fuel system concerns. Initial use of biodiesel and particularly higher blends may contribute to premature filter plugging from loosening normal levels of gums and varnish on tank, lines, and fuel system components. |
| • | Biodiesel blends have higher clouding/filter plugging temperatures than base diesel fuels and must be blended for an acceptable clouding performance during cold operation. Fuel suppliers are expected to provide both normal and biodiesel fuels blended properly for the climatic conditions of the region of sale and time of year. Use of "summer" blends in cold seasons due to extended fuel or vehicle storage can result in filter restriction. |
| • | Biodiesel blends that are stored for extended periods of time, particularly if stored at warm temperature, may deteriorate (oxidize) and contribute to fuel system corrosion and/or filter restriction. |
| • | The finding of significant water in the filter/water separator, particularly immediately following a tank fill-up, may indicate the introduction of out of specification fuel. The presence of water in diesel fuel storage can support biological growth in diesel fuel which can lead to premature filter plugging. |
Engine or fuel system repairs resulting from the use of improper fuel, including concentrations of biodiesel that exceed 5%, are NOT covered under the terms of the new vehicle warranty. Restricted fuel filters causing engine/vehicle performance conditions should be paid by the customer and the vehicle fuel requirements reviewed with the vehicle operator.
Fuel Requirements
Notice: Never use home heating oil or gasoline in your vehicle’s diesel engine. They can cause engine damage.
The emission control system requires the use of diesel fuel with ultra low-sulfur (0.0015% by weight, or 15 ppm, maximum) content. Both Ultra Low Sulfur Diesel and Low Sulfur Diesel fuels are available in the United States and Ultra Low Sulfur Diesel fuel is available in Canada. However, only higher sulfur diesel fuel is available in Mexico.
At a minimum, the diesel fuel you use should meet the latest version of ASTM specification D 975 (Grades No. 2-D or No. 1-D S15 commonly known as Ultra Low Sulfur diesel) in the United States. In addition, the Engine Manufacturers Association (EMA) has identified properties of an improved diesel fuel for better engine performance and durability. Diesel fuels corresponding to the EMA Consensus Position -- Joint EMA/TMC Pump Grade Specification for Premium Diesel Fuel, could provide better starting, less noise, and better vehicle performance. If there are questions about the fuel you are using, contact your fuel supplier.
In the United States, for best results use No. 2-D diesel fuel year-round (above and below freezing conditions) as oil companies blend No. 2-D fuel to address climate differences. No. 1-D diesel fuel can be used in very cold temperatures (when it stays below 0°F or -18°C); however, it will produce a power and fuel economy loss. Avoid the use of No. 1-D diesel fuel in warm or hot climates. It can result in stalling, poor starting when the engine is hot, and could damage the fuel injection system.
Because of the cleansing properties of biodiesel, switching from straight diesel to a biodiesel blend can prematurely restrict the fuel filter with normal deposits in the fuel system. A fuel filter replacement might be required sooner than the recommended interval.
What Fuels to Use - Canada
The emission control system requires the use of diesel fuel with ultra low-sulfur (0.0015% by weight, or 15 ppm, maximum) content. Both Ultra Low Sulfur Diesel and Low Sulfur Diesel fuels are available in the United States and Ultra Low Sulfur Diesel fuel is available in Canada.
At a minimum, the diesel fuel you use should meet the latest version of specification CAN/CGSB-3.517 (ULS) in Canada. In addition, the Engine Manufacturers Association (EMA) has identified properties of an improved diesel fuel for better engine performance and durability (EMA Consensus Position -- Joint EMA/TMC Pump Grade Specification for Premium Diesel Fuel). Diesel fuels corresponding to the EMA description could provide better starting, less noise, and better vehicle performance. If there are questions about the fuel you are using, contact your fuel supplier.
Canadian fuels are blended for seasonal changes. Diesel Type "A" fuel is blended for better cold weather starting (below 0°F or -18°C); however, you might notice some power and fuel economy loss. If Type "A" fuel is used in warmer temperatures, stalling and hard starting may occur. Diesel Type "B" fuel is blended for temperatures above 0°F (-18°C).
Biodiesel Fuels
It is acceptable to use diesel fuel containing up to 5% biodiesel (B5), but the final blended fuel must meet the same specification, ASTM D 975 (Grades No. 2-D or No. 1-D S15 commonly known as Ultra Low Sulfur diesel), as other fuels used in your vehicle, and the biodiesel used for making this fuel must meet the latest version of ASTM specification D 6751. Biodiesel is produced from vegetable oils or animal fat that have been chemically modified to reduce the possibility of damage to the fuel system and engine. Higher concentration (i.e., greater than B5) biodiesel-containing fuels or the use of unmodified bio-oils blended into diesel fuel at any concentration is not recommended and could damage the fuel system and engine. Such damage would not be covered by your warranty. If there are questions about the biodiesel-containing fuels you are using, contact your fuel supplier.
See your Duramax™ Diesel Owne'rs Manual for additional information.
