1990 Mercury Grand Marquis Problems

What owners report

Owners of this model year most often describe sudden or unintended acceleration when shifting into reverse or drive or while pressing the brake, and transmission shifting problems. Airbag warning lights that flash or stay on, engine shutdowns linked to ignition-module problems, and under-hood electrical fires are also reported. Most complaints were filed in the late 1990s and early 2000s, and mileage is listed in only some of them.

1. 1
   Vehicle speed control

   Sudden acceleration when shifting or braking

   • 7 complaints (13%)
   • median 64,500 mi at 19.6 yrs old (2 state mileage, few)
   • 4 mention a crash, fire or injury
   • filed 1995–2015

   Owners describe the car taking off suddenly or accelerating without warning when the shift lever is moved into reverse or drive, or while the brake pedal is pressed. Some describe the speed control engaging on its own while backing, the engine racing in reverse, or the throttle opening at low speed. In some complaints the dealer or a mechanic could not identify the source of the problem. Mileage is given in only some of these complaints, from about 40,000 to 89,000 miles, and most events happen while shifting or braking.

   What to check: Ask whether any repairs to the throttle, speed control, or transmission shift have been done, and request the records. During a pre-purchase inspection, have a mechanic check the throttle linkage and the speed control system.

   2 excerpts from owner complaints in NHTSA records

   “I embarked on a routine trip to dinner in my mother's 1990 Mercury marquis. I started the engine which idled normally, as usual. With my foot on the brake, I engaged the shift lever into the r position which resulted in immediate accelleration in a reverse direction. I swerved the car to the left to avoid children across the street and rammed a vehicle parked on the street. The vehicle stopped on impact with the other vehicle and returned to normal idle speed. …”

   NHTSA complaint #10122006, filed 2005-05, 89,000 miles

   “Engine occasionally surges when placed into reverse. The engine immediately races and the car even convulses. The only thing that stops it is to turn off the engine. This is my mom's car and she rarely drives it.”

   NHTSA complaint #10745543, filed 2015-08, 40,000 miles
2. 2
   Transmission and drivetrain

   Transmission shifting problems and failures

   • 9 complaints (16%)
   • median 127,989 mi at 13.8 yrs old (3 state mileage, few)
   • 2 mention a crash, fire or injury
   • filed 1995–2005

   Owners describe automatic transmissions that do not shift properly, such as failing to move out of first gear or shifting roughly in overdrive. Some describe the accelerator pedal going to the floor with a loss of forward power, and some report transmission repairs costing more than a thousand dollars. Some owners say a plastic grommet near the manifold overheats and corrodes over time, and an owner replaced it with metal parts. Where mileage is listed, the complaints are around 128,000 miles, though an owner also describes earlier transmission problems at lower mileage.

   What to check: Ask for transmission service and repair records, including any overhaul or grommet replacement. On a test drive, check for hesitation or rough shifts from first gear and in overdrive.

   2 excerpts from owner complaints in NHTSA records

   “While driving at normal speed accelerator pedal went to the floor, and vehicle lost all power to go forward. Dealer notified. Consumer stated this vehicle was no longer under warranty. Transmission cost over $1000.00.”

   NHTSA complaint #10027032, filed 2003-08, 127,998 miles

   “While driving automatic transmission doesn't shift properly from the first gear, wont shift. Dealer notified. Vehicle was taken to independent shop and overhauled. Transmission at cost over $1000.00”

   NHTSA complaint #10027039, filed 2003-08, 127,989 miles
3. 3
   Air bags

   Airbag warning light flashing or staying on

   • 8 complaints (14%)
   • typically at 10.2 yrs old
   • filed 1996–2004

   Owners describe the airbag warning light flashing, flickering, or staying on, and in some cases blinking in a repeating pattern. Some owners ask whether a recall applies to their car and whether the recall repair was done. According to a complaint, the dealer linked the light to a center crash sensor and said the airbag would not deploy in a crash. None of these complaints lists mileage, and the light is described as flashing, flickering, or staying on.

   What to check: Ask whether the airbag light was diagnosed and whether any airbag recall repair was completed, and ask for the paperwork. Have a mechanic read the airbag system fault codes during a pre-purchase inspection.

   2 excerpts from owner complaints in NHTSA records

   “I have a concern about the air bag in my car, which is a 1990 Mercury Grand Marquis. The air bag light comes on. It doesn't stay on constantly, but it does 'flicker' or it will stay on for a few seconds. There are times where it doesn't come on at all, but I am still concerned. I was wondering, since there was a recall on the part of the airbag, if I should have it looked at.”

   NHTSA complaint #10090562, filed 2004-09

   “The 'air bag' light on my dash is lighting up. It doesn't stay on constantly, but it does flash, which concerns me. It doesn't go on every time my car is on, but it does flash about 95% of the time. I saw the recall and want to know if my vehicle was involved and if it was fixed.”

   NHTSA complaint #10091040, filed 2004-09
4. 4
   Electrical system

   Under-hood electrical fires and wiring shorts

   • 8 complaints (14%)
   • typically at 8.0 yrs old
   • 5 mention a crash, fire or injury
   • filed 1995–2001

   Owners describe smoke and fire from the alternator or wiring, including a fire that started under the hood while driving. Some describe an alternator that filled with smoke before bursting into flames, and a wiring harness short that kept interior and exterior lights on and melted a fuse. Some owners report the vehicle was a total loss after the fire. None of these complaints lists mileage, and the fires are described while driving or shortly after parking.

   What to check: Ask whether the alternator or wiring was replaced and request the repair records. Check the under-hood wiring and fuses for melting, discoloration, or a burning smell, and have a mechanic inspect the charging system during a pre-purchase inspection.

   2 excerpts from owner complaints in NHTSA records

   “Vehicle was driven approximately one mile and parked. Upon exiting the vehicle, the operator noticed smoke coming from under the hood. After opening the hood, the operator identified the source of the smoke as the alternator. Operator continued to observe the vehicle and noted that the volume of smoke was increasing. After approximately two minutes, the alternator burst into flames. Arcing was seen and heard within the alternator. …”

   NHTSA complaint #738760, filed 2001-01

   “Wiring harness shorted out, causing all lights inside vehicle, as well as tail lights and park lights to stay on. In addition, fuse burned and melted. Repairs made at owner's expense.”

   NHTSA complaint #836106, filed 1999-03
5. 5
   Electrical system

   Engine shutdown while driving (ignition module)

   • 5 complaints (9%)
   • typically at 11.5 yrs old
   • 1 mention a crash, fire or injury
   • filed 1995–2002

   Owners describe the engine shutting off or quitting while driving, including on highways and in heavy traffic. Some complaints link the shutdowns to the thick film ignition module, which owners say failed and was replaced. Some owners report the car would not restart after shutting down on the highway. No mileage is listed for these complaints, and the shutdowns are described during highway driving or in traffic.

   What to check: Ask whether the ignition module has been replaced and whether any related repair records exist. On a test drive at highway speed, listen for stalling or hesitation, and have a mechanic check the ignition system during a pre-purchase inspection.

   An excerpt from owner complaints in NHTSA records

   “I was proceeding home in evening rush hour traffic when the car engine quit instantaneously. I was forced to stop in the right lane of traffic. Although in the right lane I could not pull off of the road because there was a barrier with no shoulder for me to pull onto. Fortunately I was not hit by another car although I was sitting where traffic had to stop abruptly and swerve to avoid hitting me. The car was sitting in traffic until a tow truck arrived approximately one hour later. …”

   NHTSA complaint #750972, filed 2001-08

Buying note. Anyone considering this model year may want service records for the transmission, airbag system, and ignition or charging repairs. A pre-purchase inspection that checks shifting, throttle response, the airbag warning light, and engine stability at highway speed matches the issues owners report most.

Summary written with AI from a sample of 31 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.