MercuryGrand Marquis1986Overview/mercury/grand-marquis/1986/base/

1986 Mercury Grand Marquis

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1986 Grand Marquis.

Transmission Automatic 4-spd

The 1986 Mercury Grand Marquis pairs an automatic 4-speed transmission with a powertrain requiring 4.0 quarts of 5W-30, 10W-30, or 10W-40 viscosity oil to deliver EPA estimates of 16 city and 24 highway mpg. Its reliability profile is notably contained, marked by just 21 total owner complaints and two recalls that predominantly center on the electrical system. When contextualized against the model's broader 1990–2011 complaint history—which peaked at 487 issues in 2005 and reached a low of 9 in 2011—the 1986 model year stands as an early, remarkably stable iteration, indicating robust foundational reliability long before later generations faced escalating problems.

Model year201120102009200820072006200520041986

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.0 qtOEM · verified
Engine oil type5W-30 / 10W-30 / 10W-40OEM · verified
EPA fuel economy16/24/19 mpgEPA · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

OE service part numbers OEM · verified

Serpentine beltD9PZ8620H alt JH325
ThermostatRT1052 discontinued

Full specifications

Engine, drivetrain, dimensions and economy.

Engine & drivetrain NHTSA vPIC

TransmissionAutomatic 4-spd

Dimensions & weight NHTSA vPIC

Overall length215 in
Overall width79.1 in
Overall height56.7 in
Wheelbase114.2 in
Curb weight3993 lb

Ratings & economy EPA / vPIC

EPA city / highway / combined16 / 24 / 19 mpg
DrivetrainRear-Wheel Drive
Passenger volume111 cu ft
Cargo volume22 cu ft
Recommended fuelRegular Gasoline

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.0 qt of 5W-30 / 10W-30 / 10W-40 engine oil, DOT 3 brake fluid.

Lubricants & capacities

Brake FluidDOT 3
Engine CoolantETHYLENE GLYCOL
Engine Oil5W-30 · 10W-30 · 10W-40 · 15W-40 · 20W-40 · 20W-50
Engine Oil Capacity4.0 qt
Engine Oil5W-30 · 10W-30 · 10W-40 · 15W-40 · 20W-40 · 20W-50
Engine Oil Capacity4.0 qt
Engine Oil5W-30 · 10W-30 · 10W-40 · 15W-40 · 20W-40 · 20W-50
Engine Oil Capacity4.0 qt

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter at 7,500 mi; coolant every 30,000 mi. The big-interval services (every 30,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

At 7,500 miEngine Oil Filter (replace)
Every 7,500 miEngine Oil (drain & refill)
Every 15,000 miEngine Oil Filter (replace)
Every 30,000 miAccessory Drive Belt (inspect) · Air Cleaner Manifold Heat Control Actuator (inspect) · Choke System (inspect) · Engine Air Filter Element (replace) · Engine Breather Filter (replace) · Engine Coolant System (drain, flush & refill)
Every 60,000 miEGR Vacuum Control Solenoid Filter (replace)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

The 1986 Mercury Grand Marquis sits at the very beginning of the generation’s federal record, which starts in 1990. The year-by-year data shows a clear upward trend in complaints from 61 in 1990 to a peak of 383 in 1997, followed by a gradual decline—meaning the 1986 model year was on the road during the lowest-reporting period of the generation. For the 1986 model itself, the top complaint area is Electrical System (10 reports), and there are 11 fire complaints but zero crash complaints; the data does not specify root causes for these issues. Compared to later years like 1992 (346 complaints) or 1997 (383 complaints), the 1986’s complaint volume appears modest, but this could reflect lower reporting rates or fewer surviving vehicles rather than inherent reliability. The 11 fire complaints are a notable red flag, though without further detail their severity is unclear. Overall, the 1986 is an early-generation example with a relatively low complaint count, but the fire reports and lack of direct recall data for that year mean a thorough pre-purchase inspection is essential; it is a cautious buy if you can verify the electrical system and any fire-related concerns have been addressed.

2
Open recalls
NHTSA campaigns
22
Service bulletins
Manufacturer communications
3
ODI investigations
Office of Defects Investigation
21
Owner complaints
0 involved a crash · 11 a fire

Owner complaints filed with NHTSA, by component

All 21 complaints on record, top 8 components.

Electrical System10
Engine & Engine Cooling4
Power Train1
Service Brakes, Hydraulic,Electrical System1
Structure1
Vehicle Speed Control1
Steering1
Service Brakes, Hydraulic1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 2 of 2 campaigns on record for this vehicle.

07E064000Fuel System, Gasoline:Delivery:Fuel PumpReported 27/08/2007

CERTAIN FEDERAL-MOGUL AFTERMARKET FUEL PUMPS SOLD UNDER THE BRAND NAMES OF CARTER, ACCUFLOW, NAPA, TRUFLOW, PARTS DEPO, AND PARTS MASTER, SHIPPED BETWEEN AUGUST 2006 AND JULY 2007 FOR USE ON THE VEHICLES LISTED ABOVE… Remedy: FEDERAL-MOGUL WILL NOTIFY OWNERS AND REPLACE THE DEFECTIVE FUEL PUMPS FREE OF CHARGE. THE RECALL BEGAN ON OCTOBER 15, 2007. OWNERS CAN CONTACT FEDERAL-MOGUL AT 248-354-7700.

87V139000Fuel System, Gasoline:Delivery:Hoses, Lines/Piping, And FittingsReported 04/09/1987

SPRING LOCK FUEL LINE COUPLING MAY NOT BE PROPERLY ENGAGED. Remedy: INSTALL RETAINER CLIPS OVER THE COUPLINGS TO PREVENT COUPLING SEPARATION AND FUEL LEAKAGE.

Technical service bulletins NHTSA · verified

Showing 5 of 22 bulletins on record with NHTSA.

BulletinDateComponentSummary
011562001-08-06VisibilitySOME VEHICLES MAY EXHIBIT HEATER CORE LEAKS. *SLC
011572001-08-06Unknown Or OtherINFORMATION REGARDING TRANSMISSION FLUID USAGE CHARTS. *SLC
0023102000-11-13Power TrainSUBJECT REGARDING CONTAMINATION FROM PRIOR TRANSMISSION CONCERNS OR EXCESS WEAR MAY BE…
00152000-01-10Power TrainINFORMATION REGARDING THE NEW TRANSMISSION COOLER FLUSHER- SERVICE TIP. *MJS
992221999-10-18Electrical SystemSUBJECT ON A WIRE HARNESS TERMINAL REPAIR KIT AVAILABLE FOR REPAIRING ELECTRICAL WIRING…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific Grand Marquis. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

How much oil does the 1986 Grand Marquis take?

4.0 qt of 30W. MULTI-VISCOSITY: BELOW 100 degrees F 5W-30. ABOVE 0 degrees F 10W-30 OR 10W-40. ABOVE 10 degrees F 15W-40. ABOVE 20 degrees F 20W-40 OR 20W-50, per the factory manual.

Does the 1986 Grand Marquis have open recalls?

NHTSA lists 2 recall campaign(s) for this model year. Check your specific vehicle by VIN.

What gas mileage does the Grand Marquis get?

EPA figures are 16 city / 24 highway / 19 combined mpg.