Very Cold Weather Operation; Water In Fuel - GMC 2006 DURAMAX Manual

It is acceptable to use diesel fuel containing up to 5%
biodiesel (B5), but the final blended fuel must meet the
same specification, CAN/CGSB-3.517 (Low Sulfur
Diesel) in Canada, 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 your 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
your 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.

Very Cold Weather Operation

Follow the instructions listed previously under the
heading "What Fuel to Use."
Notice: Never use home heating oil or gasoline in
your diesel engine. They can cause engine damage.
In cold weather, your fuel filter may become clogged
(waxed). To unclog it, move the vehicle to a warm garage
area and warm the filter to between 32°F and 50°F
(0°C to 10°C). You will not need to replace it. Additional
information on the fuel filter follows.

Water in Fuel

CAUTION:
{
Diesel fuel containing water is still flammable.
You could be burned. If you ever try to drain
water from your fuel, keep sparks, flames and
smoking materials away from the mixture.
Notice: If there is water in your diesel fuel and the
weather is warm or humid, fungus and bacteria can
grow in the fuel. They can damage your fuel system
and fuel operated heater (FOH) (if equipped). A diesel
fuel biocide can be used to sterilize your fuel system.
However, your fuel system may still need to be
cleaned. Your dealer can advise you of the
appropriate solution.
If your fuel tank needs to be purged to remove
water, see your dealer or a qualified technician.
Improper purging can damage your fuel system
and block your FOH.
Sometimes, water can be pumped into your fuel tank
along with your diesel fuel. This can happen if a service
station doesn't regularly inspect and clean its fuel tanks,
or if it gets contaminated fuel from its suppliers.
5-5