GMC S-15
Maintenance specs for 3 variants of the GMC S-15 — from 1985 to 1990.
1985–1990 GMC S-15
2.5L I4 (LQ2) · RWD
92 hp / 134 lb-ft
Transmission
Type5-Speed Manual
FluidGL-4 75W-90
Drain & fill2.2 qt
Full capacity2.2 qt
Power Steering
TypeHydraulic
FluidDexron III ATF
Differentials
Rear fluid80W-90 GL-5
Fuel
Tank13 gal
TypeRegular 87
Service Intervals
Oil change5,000 mi
Trans service50,000 mi
Coolant flush30,000 mi
Spark plugs30,000 mi
Timingchain (no scheduled replacement)
Air filter45,000 mi
Drive belt100,000 mi
1985–1990 GMC S-15
2.8L V6 (LB4) · RWD
125 hp / 150 lb-ft
Transmission
Type4-Speed Automatic (700R4)
FluidDexron III
Drain & fill5 qt
Full capacity10 qt
Power Steering
TypeHydraulic
FluidDexron III ATF
Differentials
Rear fluid80W-90 GL-5
Fuel
Tank13 gal
TypeRegular 87
Service Intervals
Oil change5,000 mi
Trans service50,000 mi
Coolant flush30,000 mi
Spark plugs30,000 mi
Timingchain (no scheduled replacement)
Air filter45,000 mi
Drive belt100,000 mi
1988–1990 GMC S-15
4.3L V6 (L35) · RWD
160 hp / 235 lb-ft
Transmission
Type4-Speed Automatic (700R4)
FluidDexron III
Drain & fill5 qt
Full capacity10 qt
Power Steering
TypeHydraulic
FluidDexron III ATF
Differentials
Rear fluid80W-90 GL-5
Fuel
Tank20 gal
TypeRegular 87
Service Intervals
Oil change5,000 mi
Trans service50,000 mi
Coolant flush30,000 mi
Spark plugs100,000 mi
Timingchain (no scheduled replacement)
Air filter45,000 mi
Drive belt100,000 mi