ROUGH IDLE/COOLANT LOSS CAUSE AND CORRECTION. GMC Truck S15 Pickup - 2WD 1983

For 1990-2009 cars

# ROUGH IDLE/COOLANT LOSS CAUSE AND CORRECTION

#### MODELS: 1983 "S/T" TRUCK

Some 1983 S/T trucks with 2.0L LQ5 engines may exhibit poor or rough idle, and/or coolant loss. This condition may be caused by a warped EGR valve adaptor (aluminum). Warpage in this area can result in some of the following conditions.

1. Leakage across the base of the EGR valve.

2. Leakage at the base of the EGR valve to atmosphere.

3. Leakage of coolant from head to EGR valve inlet or outlet.

4. Leakage of coolant to outside of head.

Conditions #1 and #2 generally result in rough idle. Conditions #3 and #4 can be detected by a coolant loss.

Replacement with P/N 14077282 adaptor (cast iron) and P/N 14028962 stud - (2 needed, torque to 40 N.m) will correct these conditions.

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.