1991 Mercury Grand Marquis: common problems

Owners of the 1991 Mercury Grand Marquis filed 82 complaints with NHTSA, most often about electrical system and vehicle speed control. Details by component below, with sources.

Key figures

Owner complaints: 82
involving a crash: 12

What fails most often

1 Electrical system 26% of all complaints
2 Vehicle speed control 15% of all complaints
3 Air bags 13% of all complaints
4 Service brakes 13% of all complaints
5 Engine and cooling 12% of all complaints
6 Powertrain 10% of all complaints
7 Fuel system 5% of all complaints
8 Structure 5% of all complaints

Circle size and colour show each component’s share of NHTSA complaints. Schematic only, not a drawing of the exact model.

Electrical system: 21 complaints (26% of all).
Vehicle speed control: 12 complaints (15% of all), 7 of them with a crash reported by the owner.
Air bags: 11 complaints (13% of all), 4 of them with a crash reported by the owner.
Service brakes: 11 complaints (13% of all).
Engine and cooling: 10 complaints (12% of all).

Engines and transmissions

US-market versions per EPA. On the right: how many NHTSA complaints name this engine or transmission type.

5 L · petrol · 8 cyl
automatic, 4-speed

Drive: RWD

Symptoms owners describe

How many of the 82 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).

smoke, burning smell, fire18 · 22%
door locks, latches, handles5 · 6%
stalls while driving5 · 6%
airbag warning light4 · 5%
unintended acceleration4 · 5%
transmission slipping3 · 4%
warning lights, check engine3 · 4%
windows, sunroof3 · 4%
knocking, grinding or other noise2 · 2%
rust, corrosion2 · 2%

Components owners complain about

Component	Owner complaints	involving a crash
Electrical system	21	0
Vehicle speed control	12	7
Air bags	11	4
Service brakes	11	0
Engine and cooling	10	0
Powertrain	8	1
Fuel system	4	0
Structure	4	0
Exterior lighting	3	0
Visibility	3	0
Latches, locks, linkages	2	0
Parking brake	2	1
Suspension	2	0
Equipment	1	0

What owners report

Short excerpts of NHTSA complaints in the original wording. These are owner statements not verified by NHTSA; personal data removed.

It knocked me down and ran over me with the front tire. It ran over my legs and chest. It then scrapped and dented my wife's car, and was halted by running in to the rear end of my neighbor's car across the street. He is a police officer and he filed the report.
Powertrain · crash · 2001-07-12 · NHTSA complaint #748041
The consumer released the emergency brake and the vehicle opened up, causing the vehicle to accelerate up 65 mph, and hit another vehicle.
Parking brake · crash · 1999-08-06 · NHTSA complaint #844540
During cold startup shifted into reverse vehicle surged rearward. When placing selector gear into neutral slipped to drive gear, surged forward. Ran into house, and wheels still spinning with both feet on braking pedal.
Vehicle speed control · crash · 1997-06-04 · NHTSA complaint #812785
While driving accelerator stuck, had an accident, brakes did not work.
Vehicle speed control · crash · 1996-05-06 · NHTSA complaint #984092
Power window on the passenger side does not go down at all.the car keeps killing the battery and I've already spent money on an alternator used. Brake pedal seems stiff at times and does not grab well at times. Air bag light has been blinking ever since I bought car because of air bag failure.
Air bags · 2004-04-22 · NHTSA complaint #10070780
After parking vehicle in driveway consumer was emptying the trunk and noticed smoke coming from under the hood. A fire soon erupted from the passenger's side under the hood, and was quickly extinguished.
Electrical system · 2003-08-15 · NHTSA complaint #10034051
Vehicle starts and rides for about 20 miles, then if I have to stop for some reason the car stalls especially if I have to back up. This happens almost dailly. No accidents yet but I am afraid I will cause a serious accident with this problem. I think my car should be recalled and have thid problem fixed.
Engine and cooling · 2001-11-20 · NHTSA complaint #754650
Consumer was driving about a quarter of a mile when smoke started to come from engine. Consumer pulled over and vehicle caught on fire. Has not contacted dealer.
Electrical system · 2001-08-31 · NHTSA complaint #895593

When owners complained

NHTSA complaints by filing year. The peak shows at what age the problems show up most.

199514
199613
199713
19989
199917
20006
20015
20021
20031
20042
20181

Comparison

By complaint count this model year ranks 4,021 of 36,656 model years in the NHTSA data (top 11% most complained about).

On average one model year of the Grand Marquis has 117 complaints (34 years in the data). This year has 82, below average.

What to check before buying

Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
Vehicle speed control. Accelerator pedal, cruise control, throttle codes.
Air bags. Check the SRS light, stored codes and airbag/curtain status after any impact.
Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.

Other years of this model

Questions and answers

What are the most common problems with the 1991 Mercury Grand Marquis?

Owner complaints to NHTSA most often mention: electrical system, vehicle speed control, air bags. Total complaints: 82. The most frequent symptoms in complaint texts: smoke, burning smell, fire (22%), door locks, latches, handles (6%), stalls while driving (6%).

How many service bulletins (TSB) were issued for the 1991 Mercury Grand Marquis?

NHTSA lists 0 manufacturer service bulletins for this year. A bulletin tells dealers how to diagnose or fix a known issue; it is not a recall.

Should I buy a 1991 Mercury Grand Marquis from a US auction?

Owner complaints describe defects, not crash damage. Before bidding, check the components listed above and review the lot photos: VinWind builds a report of visible and hidden damage by VIN.

Other 1991 models

Read also

Sources: public NHTSA data (USA): service bulletins and owner complaints; YouTube: links to videos credited to their authors. Complaints are owner statements not verified by NHTSA, and describe defects rather than crash damage. Data updated 2026-11-05.