1991 Mercury Grand Marquis Service and Repair Manual

This factory service and repair manual for the 1991 Mercury Grand Marquis was written for a four-door sedan offered in GS and LS trim with a single engine, the 5.0L overhead-valve V8 of 302 cubic inches, naturally aspirated and burning gasoline. With one drivetrain to describe, the transmission, driveline, brake and restraint sections stay specific: procedures give the sequence, the specifications give the figures to hit, and the wiring diagrams show the circuits as they were built for these two trims.

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 1991 Grand Marquis. Two recalls stand on the federal record. One concerns a park cam in the park rod assembly whose surface was not hard enough, so the transmission may fail to engage Park or drop out of it, and the car can roll away when the parking brake is off. The other covers air bag inflators with assembly damage to their threaded parts, which can separate on deployment and vent hot gases into the cabin. Complaints run to 90: 21 electrical, 12 speed control and 11 on the air bags, each a system this manual diagnoses.