Chevrolet Impala Bi-Fuel (Gasoline/CNG) Supplement (GMNA-Localizing-U.
S/Canada-9087624) - 2016 - CRC - 8/17/15
Driving and Operating 13
dispenser to the fill valve and begin
refueling again. If a leak is still
present, replace the fill valve O-ring.
{Warning
Attempting to fill a CNG fuel
system that has a missing or
damaged O‐ring is dangerous.
Natural gas can leak. If the
natural gas is ignited, you or
others could be injured. Replace
the O‐ring before filling the tank.
Fill Valve O-RingTo replace the fill valve O-ring:
1. Carefully remove the O-ring from the groove in the fill
receptacle. A small flat-blade
or pointed tool can be used.
2. Make sure the groove is clean and free of dirt and debris.
3. Install the new O-ring in the groove in the fill receptacle.
Make sure the O-ring is
properly seated in the groove.
If a leak is still present after you
have replaced the O-ring, have an
authorized dealer inspect the
sealing O-ring in the fill receptacle.
If dirt or other debris is adhering to
the inside of the fuel fill receptacle,
gas may leak out after refueling.
If you need to add more fuel, repeat
the refueling procedure again.
See an authorized GM dealer for
replacement O-rings.
Fuel Filling Problems
If you experience very slow fill rates,
the CNG fuel filter in the fill valve
may require service. Slow fill rates
may also be caused by ice
formation on the fuel receptacle.
Use only CNG fuel meeting
recommended CNG fuel standards.
If you experience reduced range
during CNG operation and none of
the conditions described earlier in
this section apply, the CNG fuel tank
may require service. This may be
caused by the buildup of water, oil,
or debris inside the tank or an
inoperative tank valve. In either
case, take the vehicle to an
authorized GM dealer for service.
