Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 1984 Grand Marquis.
The 1984 Mercury Grand Marquis is recorded with a 4.0‑quart oil capacity and oil viscosities of 5W‑30, 10W‑30, or 10W‑40. It pairs an Automatic 4‑speed transmission with EPA fuel‑economy ratings of 14/20/16 mpg. In its early reliability record the model shows 23 total owner complaints, with electrical system issues as the most frequent complaint and two recalls noted. The broader complaint history for the Grand Marquis spans 1990‑2011, peaking at 487 complaints in 2005 and declining to 9 complaints by 2011, indicating that the 1984 model year precedes the most heavily documented period of issues.
Fluid capacities, tune-up values and fuel economy at a glance.
Engine, drivetrain, dimensions and economy.
| Transmission | Automatic 4-spd |
| Overall length | 214.2 in |
| Overall width | 77.6 in |
| Overall height | 55.1 in |
| Wheelbase | 114.2 in |
| Curb weight | 3735 lb |
| Weight distribution (front / rear) | 56/44 |
| EPA city / highway / combined | 14 / 20 / 16 mpg |
| Passenger volume | 111 cu ft |
| Cargo volume | 22 cu ft |
| Recommended fuel | Regular Gasoline |
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.
| Brake Fluid | DOT 3 |
| Engine Coolant | ETHYLENE GLYCOL |
| Engine Oil | 5W-30 · 10W-30 · 10W-40 · 15W-40 · 20W-40 · 20W-50 |
| Engine Oil Capacity | 4.0 qt |
| Engine Oil | 5W-30 · 10W-30 · 10W-40 · 15W-40 · 20W-40 · 20W-50 |
| Engine Oil Capacity | 4.0 qt |
| Engine Oil | 5W-30 · 10W-30 · 10W-40 · 15W-40 · 20W-40 · 20W-50 |
| Engine Oil Capacity | 4.0 qt |
Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.
In the 1984 Mercury Grand Marquis, the federal record shows 7 electrical complaints, 5 engine and cooling complaints, 4 vehicle speed control complaints, and 3 structure complaints, with 2 crash and 6 fire complaints recorded. The year‑by‑year trend from 1990 to 2011 displays a sharp rise in complaints beginning in 1992 (346 complaints), peaking in 2005 (487 complaints), then sharply declining after 2006. The 1984 model sits well before this peak, implying it benefited from a period of relatively lower complaint activity compared to the mid‑2000s surge. However, the data does not provide specific recall numbers for 1984, so the root causes of the 1984 complaints remain unspecified. Given the lower complaint volume before the 1990s spike and the absence of known major recalls in the provided data, 1984 is likely a more reliable year to purchase, though a thorough mechanical inspection is still advised.
All 23 complaints on record, top 7 components.
Source: NHTSA Office of Defects Investigation complaint database.
Showing 2 of 2 campaigns on record for this vehicle.
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.
THE BOLTS THAT ATTACH THE D-SHAPED RING FOR THE SHOULDER BELT ARE INADEQUATELY SUPPORTED BY THE MATERIAL IN WHICH THEY ARE MOUNTED. THE ATTACHMENT DOES NOT COMPLY WITH THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY… Remedy: DEALERS WILL INSTALL NEW ATTACHING HARDWARE TO IMPROVE THE STRENGTH OF THE MOUNTING.
Showing 5 of 12 bulletins on record with NHTSA.
| Bulletin | Date | Component | Summary |
|---|---|---|---|
| 01157 | 2001-08-06 | Unknown Or Other | INFORMATION REGARDING TRANSMISSION FLUID USAGE CHARTS. *SLC |
| 002310 | 2000-11-13 | Power Train | SUBJECT REGARDING CONTAMINATION FROM PRIOR TRANSMISSION CONCERNS OR EXCESS WEAR MAY BE… |
| 98246 | 1998-12-07 | Electrical System | FORD MOTOR COMPANY HAS RELEASED A NEW ELECTRICAL GREASE ( F8AZ - 19G208-AA ) TO REDUCE… |
| 9888 | 1998-04-27 | Power Train | INFORMATION ON A NEW TRANSMISSION FLUID USAGE CHART. *YC |
| 9874 | 1998-04-13 | Engine And Engine Cooling | A NEW SILICONE GASKET AND SEALANT. *YC |
The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.
Decode factory build data for a specific vehicle by VIN.
Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.
Cross-vehicle references for the kinds of data on this page.
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.
NHTSA lists 2 recall campaign(s) for this model year. Check your specific vehicle by VIN.
EPA figures are 14 city / 20 highway / 16 combined mpg.