GMC TruckS15 4WD1991Overview/gmc-truck/s15-4wd/1991/base/

1991 GMC Truck S15 4WD

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1991 S15 4WD.

The 1991 GMC Truck S15 4WD is the four-wheel-drive entry in the S15 line, and its maintenance schedule specifies 4 quarts of 5W-30 API engine oil. Within the 1990–2001 model run, this year stands as the most complained-about example with nine owner grievances, led by Service Brakes, Hydraulic, and five recalls to its name. That volume makes it the reliability outlier of the generation—1999, by comparison, logged only one complaint—so researchers should treat its brake and recall histories as the primary focal points when benchmarking this vintage against later years in the S15 series.

Model year1992199119861985

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4 qtOEM · verified
Engine oil type5W-30 APIOEM · verified
Lug nut torque80 ft-lbsOEM · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses OE oil filter 12737090. Note the factory fuel filter and front wiper blades are now discontinued — plan on a superseded or quality aftermarket equivalent, which the part pages below list where known. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

OE service part numbers OEM · verified

Engine oil filter12737090
Engine air filter25040929
Fuel filter25171792 discontinued
Spark plug19302741
Front wiper blades12363297 discontinued
Serpentine belt19244944 alt 10230729
Thermostat10190925 alt 10207373

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4 qt of 5W-30 API engine oil, 80W-90 · GL-5 in the differential, DOT 3 brake fluid. Torque lug nuts to 80 ft-lbs.

Lubricants & capacities

Brake FluidDOT 3
Differential Gear Oil80W-90 · GL-5
Differential Gear Oil Capacity4.5 qt
Differential Gear Oil80W-90 · GL-5
Differential Gear Oil Capacity10.0 qt
Engine CoolantETHYLENE GLYCOL
Engine Oil5W-30 · API
Engine Oil Capacity4 qt

Chassis torques

Lug Nuts80 ft-lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 7,500 mi; coolant every 30,000 mi. The big-interval services (every 30,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

At 7,500 miDrive Axle Assembly (drain & refill) · Throttle Body (torque) · Tire & Wheel Assembly (rotate)
Every 7,500 miBody Latches, Locks & Hinges (inspect) · Brake Line (inspect) · Brake Linings (inspect) · CV Joint Boot (inspect) · Driveshaft U-Joint (lubricate) · Engine Oil (drain & refill)
Every 15,000 miTire & Wheel Assembly (rotate)
Every 30,000 miClutch Cross Shaft (lubricate) · Clutch Release Lever Pivot Points (lubricate) · EGR System (inspect) · Early Fuel Evaporation System (inspect) · Engine Air Filter Element (replace) · Engine Coolant System (drain, flush & refill)
Every 60,000 miAccessory Drive Belt (inspect) · Fuel Filter (replace) · Fuel Line (inspect) · Fuel Tank (inspect) · Fuel Tank Filler Cap (inspect) · Ignition Timing (inspect)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

Owner complaints about the 1991 GMC Truck S15 4WD dominate in one area — the service brakes, hydraulic, 5 of 9 reports (56%), well ahead of the next concern. None of this vehicle's 5 recall campaigns target the service brakes, hydraulic, so those reports read as owner-reported wear-and-tear rather than an acknowledged defect. 0 of the reports describe a crash and 0 a fire — a small share of the total, but worth weighing against the service brakes, hydraulic pattern above. These are tallies of what owners actually reported to the federal government, not an editorial score — and higher-selling models naturally rack up more reports.

5
Open recalls
NHTSA campaigns
1
Service bulletins
Manufacturer communications
1
ODI investigations
Office of Defects Investigation
9
Owner complaints
0 involved a crash · 0 a fire
Owner complaints by model year NHTSA · this generation & adjacent

Owner complaints filed with NHTSA, by component

All 9 complaints on record, top 4 components.

Service Brakes, Hydraulic5
Seat Belts2
Service Brakes, Hydraulic,Engine & Engine Cooling1
Service Brakes, Hydraulic,Power Train,Electrical System1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 5 campaigns on record for this vehicle.

06E049000Exterior LightingReported 24/05/2006

CERTAIN CK MOTORSPORTS COMBINATION HEADLIGHTS, CLEAR CORNER, BUMPER, AND SIDE MARKER LIGHTS SOLD AS REPLACEMENT LAMPS FOR USE ON THE PASSENGER VEHICLES LISTED ABOVE. SOME COMBINATION LAMPS THAT ARE NOT EQUIPPED WITH… Remedy: CK MOTORSPORT WILL NOTIFY OWNERS AND REPLACE THE NONCOMPLIANT LAMPS FREE OF CHARGE. THE RECALL BEGAN ON JULY 1, 2006. OWNERS MAY CONTACT CK MOTORSPORT AT 1-909-610-7211.

06E026000Exterior LightingReported 23/03/2006

CERTAIN PRO-A MOTORS CORNER LAMPS, TURN SIGNALS, AND HEADLIGHTS SOLD AS REPLACEMENT LAMPS FOR USE ON CERTAIN PASSENGER VEHICLES LISTED ABOVE. SOME COMBINATION LAMPS THAT ARE NOT EQUIPPED WITH AMBER SIDE REFLECTORS FAIL… Remedy: PRO-A MOTORS WILL NOTIFY OWNERS AND OFFER TO REPURCHASE THE LAMPS. THE RECALL BEGAN ON APRIL 3, 2006. OWNERS MAY CONTACT PRO-A MOTORS AT 323-838-2988.

Technical service bulletins NHTSA · verified

Showing 1 of 1 bulletins on record with NHTSA.

BulletinDateComponentSummary
990730016A2002-10-01Power TrainDIAGNOSTIC INFORMATION FOR INTERMITTENT TRANSMISSION DOWNSHIFT, SLIP, BUSY/CYCLING TCC OR…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific S15 4WD. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

How much oil does the 1991 S15 4WD take?

4 qt of 5W-30 API, per the factory manual.

Does the 1991 S15 4WD have open recalls?

NHTSA lists 5 recall campaign(s) for this model year. Check your specific vehicle by VIN.