1998 GMC C3500 Service and Repair Manual
This factory service and repair manual for the 1998 GMC C3500 addresses three quite different fueling arrangements in one truck line: a turbocharged 6.5L diesel V8, a 7.4L gasoline V8, and a 5.7L V8 able to run on compressed natural gas or gasoline. The bodies number five — standard, extended and crew cab pickups and cab-and-chassis trucks with two or four doors — in Sierra SL, Sierra SLE and Sierra SLT trim. Procedures, specifications, torque values, wiring diagrams and diagnostics are arranged by system throughout.
Engines covered
- 6.5L V8 (395 cu in) — OHV, turbocharged, diesel
- 5.7L V8 (350 cu in) — OHV, naturally aspirated, CNG or gasoline
- 7.4L V8 (454 cu in) — OHV, naturally aspirated, gasoline
Body styles covered
- 2-door standard cab pickup
- 2-door cab & chassis
- 4-door cab & chassis
- 4-door crew cab pickup
- 2-door extended cab pickup
Trims covered
- Sierra SL
- Sierra SLE
- Sierra SLT
Known issues on the 1998 C3500. NHTSA's record for this model year holds a single owner complaint, and it concerns the fuel system. On a truck offered with a diesel, a gasoline V8 and a natural-gas-capable V8, fuel work is the one area where the three versions have almost nothing in common, so it pays to use the right section. Each has its own delivery components, pressure and flow specifications, safety steps and diagnostic sequences, with wiring diagrams for the pumps, sensors and controls involved.
