1990 Mercury Grand Marquis Service and Repair Manual

This factory service and repair manual for the 1990 Mercury Grand Marquis comes down to one engine, one body and two trims: the 5.0L V8 of 302 cubic inches, overhead-valve, naturally aspirated and gasoline-fueled, in a four-door sedan sold as GS or LS. That single specification makes the book direct to use, because every torque value, clearance and wiring diagram in it belongs to the car on the lift, with no need to check which engine or which body shape a given figure was written for.

Engines covered

• 5.0L V8 (302 cu in) — OHV, naturally aspirated, gasoline

Body styles covered

• 4-door sedan

Trims covered

• GS
• LS

Known issues on the 1990 Grand Marquis. One recall is on the federal record, covering an air bag inflator whose threaded parts may have been damaged during assembly. Damaged that way, those parts can separate when the deployment signal arrives, releasing hot combustion gases into the passenger compartment and injuring the people the bag was meant to protect. Owners have logged 61 complaints, 13 on the electrical system and nine each on the service brakes and speed control. Restraint, brake hydraulic and speed control diagnostics are all documented here with their specifications and torque values.