1989 Mercury Grand Marquis: common problems

Owners of the 1989 Mercury Grand Marquis filed 58 complaints with NHTSA, most often about electrical system and vehicle speed control. Details by component below, with sources.

Key figures

Owner complaints: 58
involving a crash: 8

What fails most often

1 Electrical system 28% of all complaints
2 Vehicle speed control 24% of all complaints
3 Engine and cooling 10% of all complaints
4 Powertrain 10% of all complaints
5 Fuel system 9% of all complaints
6 Service brakes 9% of all complaints
7 Tires 5% of all complaints
8 Structure 3% 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: 16 complaints (28% of all).
Vehicle speed control: 14 complaints (24% of all), 7 of them with a crash reported by the owner.
Engine and cooling: 6 complaints (10% of all).
Powertrain: 6 complaints (10% of all), 1 of them with a crash reported by the owner.
Fuel system: 5 complaints (9% 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 58 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).

smoke, burning smell, fire16 · 28%
unintended acceleration5 · 9%
rust, corrosion2 · 3%
brake failure1 · 2%
A/C or heater1 · 2%
door locks, latches, handles1 · 2%
headlights and tail lights1 · 2%
oil leak or consumption1 · 2%
overheating, coolant loss1 · 2%
rollaway, parking brake1 · 2%

Components owners complain about

Component	Owner complaints	involving a crash
Electrical system	16	0
Vehicle speed control	14	7
Engine and cooling	6	0
Powertrain	6	1
Fuel system	5	0
Service brakes	5	0
Tires	3	0
Structure	2	0
Latches, locks, linkages	1	0
Parking brake	1	0
Seat belts	1	0
Steering	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.

Vehicle accelerated on its own while starting the vehicle. Tt
Vehicle speed control · crash · 1996-01-16 · NHTSA complaint #977606
While driving at approximately 25 miles per hour in perfect weather, my w/w michelin xz4 215/70/15m/s blew out on my grand marquis from the center/top of the tire(not sidewall). There were no road hazards. The tire has a large gash, and extensively splayed steel belts exposed/torn.
Tires · 2005-10-03 · NHTSA complaint #10138416
The vehicle frame had approximately three feet of rust and corrosion. The rust was also noticed by the bracket that holds the transmission support cross member. The engine oil pan rusted out which caused an oil leak. Also two of the tires had acquired bulges.
Engine and cooling · 2003-02-12 · NHTSA complaint #10006294
While driving 70mph, the left front tire blew. The vehicle was controllable. Pulled out of way of traffic. Stopped vehicle and noticed that tread was separating from tire. Contacted triple aaa and vehicle was towed.
Tires · 2002-10-30 · NHTSA complaint #8021916
Connector overheated/melted and lost stop lights. I saved the defective connector.
Electrical system · 2001-06-19 · NHTSA complaint #746643
While driving a small part dropped out from the vehicle causeing the engine to surge and the gears to lock. The transmission also failed as the result.
Powertrain · 2000-10-12 · NHTSA complaint #872852
Pe00 020; rear seat belts will not hold when putting seatbelts in the retractor .button is defactive, it will not hold. Front drivers buckle does not hold just pops out. Odometer failed.
Powertrain · 2000-10-06 · NHTSA complaint #872494
Fuel line rusted out and leaked gasoline onto pavement, under driver's seat. This event was not caused by an accident, and did not cause an accident. This event did create a fire hazard, but it was caught in time.
Fuel system · 2000-08-22 · NHTSA complaint #726949

When owners complained

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

19956
199620
19975
19984
19997
20006
20012
20021
20033
20042
20052

Comparison

By complaint count this model year ranks 4,955 of 36,656 model years in the NHTSA data (top 14% most complained about).

On average one model year of the Grand Marquis has 117 complaints (34 years in the data). This year has 58, 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.
Engine and cooling. Radiator and fan after a frontal hit, coolant level and condition, overheating.
Powertrain. Shift quality under load, harsh shifts, transmission codes, CV joints.

Other years of this model

Questions and answers

What are the most common problems with the 1989 Mercury Grand Marquis?

Owner complaints to NHTSA most often mention: electrical system, vehicle speed control, engine and cooling. Total complaints: 58. The most frequent symptoms in complaint texts: smoke, burning smell, fire (28%), unintended acceleration (9%), rust, corrosion (3%).

How many service bulletins (TSB) were issued for the 1989 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 1989 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 1989 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.