DIESEL TIMING METER INFORMATION

Snap-On Corporation advises that luminosity probes are being damaged by being overtorqued in the cylinder head. This cracks the quartz and allows soot to get behind the lens where it cannot be cleaned. In some cases, meters have been returned for repair when only the probe was at fault. Before the probe is used, hold it up to the light to make sure it is clear. When installing the probe in the cylinder do not exceed the torque specification of 11 N.m (8 lbs. ft.).

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.