1985 Mercury Marquis: common problems

Owners of the 1985 Mercury Marquis filed 5 complaints with NHTSA, most often about electrical system and engine and cooling. Details by component below, with sources.

Key figures

Owner complaints: 5

What fails most often

1 Electrical system 20% of all complaints
2 Engine and cooling 20% of all complaints
3 Powertrain 20% of all complaints
4 Tires 20% of all complaints
5 Vehicle speed control 20% 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: 1 complaints (20% of all).
Engine and cooling: 1 complaints (20% of all).
Powertrain: 1 complaints (20% of all).
Tires: 1 complaints (20% of all).
Vehicle speed control: 1 complaints (20% of all).

Engines and transmissions

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

2.3 L · petrol · 4 cyl
3.8 L · petrol · 6 cyl
5 L · petrol · 8 cyl
automatic, 3-speed
automatic, 4-speed

Drive: RWD

Symptoms owners describe

How many of the 5 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).

A/C or heater1 · 20%
door locks, latches, handles1 · 20%
stalls while driving1 · 20%
unintended acceleration1 · 20%

Components owners complain about

Component	Owner complaints	involving a crash	Technical service bulletins (TSB)
Electrical system	1	0	0
Engine and cooling	1	0	0
Powertrain	1	0	0
Tires	1	0	0
Vehicle speed control	1	0	0

What owners report

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

Pe 00 020/tire tread separation: right rear tire experienced a tread separation (tire was still inflated) while traveling at 40 mph, with driver and three passengersin a 1985 mercury, marquis, aftermarket equipment installed at 50,000 miles, p215/75r14, and dot# hyhbs77050.
Tires · 2000-09-09 · NHTSA complaint #870073
This car has other problem's to numerous to mention,like air conditioner, door latches , rear end and back axles.
Powertrain · 2000-09-05 · NHTSA complaint #729232
While driving the vehicle came to a stop and the vehicle stalled and shut off. This happens all the time when coming to a stop. Once it stalls vehicle shuts off, vehicle will start back up . Investigation is closed, pe 87 028, stalling. Egr replaced twice and also map sensor replaced.
Engine and cooling · 1997-09-10 · NHTSA complaint #816235
Going up ramp, engine light on, making loud noise, engine surged forward quickly, applied brakes to reduce speed, going up hill, engine raced ahead. Did not take to dealer.
Vehicle speed control · 1996-12-20 · NHTSA complaint #806616
Broken wire at brake light switch, causing brake lights/cruise control/horn malfunctions.
Electrical system · 1995-05-04 · NHTSA complaint #478259

When owners complained

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

19951
19961
19971
20002

Comparison

By complaint count this model year ranks 14,282 of 36,656 model years in the NHTSA data (top 39% most complained about).

On average one model year of the Marquis has 16 complaints (25 years in the data). This year has 5, below average.

What to check before buying

Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.
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.
Tires. Tire age by DOT code, bulges, wear pattern.

Questions and answers

What are the most common problems with the 1985 Mercury Marquis?

Owner complaints to NHTSA most often mention: electrical system, engine and cooling, powertrain. Total complaints: 5. The most frequent symptoms in complaint texts: A/C or heater (20%), door locks, latches, handles (20%), stalls while driving (20%).

How many service bulletins (TSB) were issued for the 1985 Mercury 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 1985 Mercury 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 1985 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.