2008 Mercury Grand Marquis: common problems

Owners of the 2008 Mercury Grand Marquis filed 80 complaints with NHTSA, most often about steering and vehicle speed control. Details by component below, with sources.

Key figures

Owner complaints: 80
involving a crash: 11

What fails most often

1 Steering 29% of all complaints
2 Vehicle speed control 19% of all complaints
3 Service brakes 13% of all complaints
4 Electrical system 11% of all complaints
5 Structure 11% of all complaints
6 Engine and cooling 6% of all complaints
7 Exterior lighting 6% of all complaints
8 Engine 5% of all complaints

Circle size and colour show each component’s share of NHTSA complaints. Schematic only, not a drawing of the exact model.

Steering: 23 complaints (29% of all), 2 of them with a crash reported by the owner.
Vehicle speed control: 15 complaints (19% of all), 5 of them with a crash reported by the owner.
Service brakes: 10 complaints (13% of all), 1 of them with a crash reported by the owner.
Electrical system: 9 complaints (11% of all), 1 of them with a crash reported by the owner.
Structure: 9 complaints (11% of all).

Engines and transmissions

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

4.6 L · petrol · 8 cyl
automatic, 4-speed

Drive: RWD

Symptoms owners describe

How many of the 80 NHTSA complaints mention each symptom (automatic count from complaint text; one complaint can mention several).

unintended acceleration9 · 11%
steering or power steering problems8 · 10%
warning lights, check engine6 · 8%
headlights and tail lights5 · 6%
rust, corrosion5 · 6%
seat belts5 · 6%
airbag warning light2 · 3%
stalls while driving2 · 3%
vibration2 · 3%
airbags did not deploy1 · 1%

Components owners complain about

Component	Owner complaints	involving a crash
Steering	23	2
Vehicle speed control	15	5
Service brakes	10	1
Electrical system	9	1
Structure	9	0
Engine and cooling	5	0
Exterior lighting	5	0
Engine	4	0
Air bags	3	1
Equipment	3	0
Powertrain	3	1
Seat belts	3	1
Electronic stability control	2	0
Fuel/propulsion system	2	0

What owners report

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

I have a 2008 mecury grand marquis ,I was in a wreck in december 10,2017 frontal impact my air bags did not go off or work during my wreck also my seat belts did not work as well. I got hurt in the wreck because non of my safety equipment work.
Air bags · crash · 2018-07-31 · NHTSA complaint #11114762
The contact stated that while driving approximately 5 mph and attempting a left turn, a loud abnormal noise was heard from the vehicle as the power steering assist failed. The contact lost steering control of the vehicle and crashed into a ditch, causing the air bags to deploy.
Steering · crash · 2013-11-15 · NHTSA complaint #10552433
The contact stated that while depressing the brake pedal and driving approximately 5 mph, the rpm reading increased as the vehicle jerked forward. The contact stated all the warning lights on the instrument panel illuminated. The failure recurred various times causing a crash.
Vehicle speed control · crash · 2013-06-25 · NHTSA complaint #10521721
The contact was unable to stop the unintended acceleration and the vehicle drove over a curb and crashed into a sign. The contact and passenger both sustained minor injuries to their necks from the seat belt. The vehicle sustained substantial front end damages.
Vehicle speed control · crash · 2010-07-27 · NHTSA complaint #10345720
After driving in reverse and shifting into drive from a stop light the vehicle surged forward and crashed into another vehicle. A police report was not filed. One person was reported injured. Smoke was seen coming from under the hood of the vehicle. The vehicle was towed to the contacts residence.
Vehicle speed control · crash · 2010-07-07 · NHTSA complaint #10341870
The air bags failed to deploy and the seat belt did not tighten. The failure and current mileages were 17,000. Remailed 12/10/08.
Service brakes · crash · 2008-11-12 · NHTSA complaint #10248587
total collapse of upper immediate steering shaft resulting on total separation/failure and complete loss of steering. this literally separated/fell apart in my hand when i was cleaning the front seat carpeting. i had just finished driving back from a 100 mile trip.
Steering · 2026-10-13 · NHTSA complaint #11770830
The contact stated that the power steering was still operable however, the vehicle would drift to the left or right with no input on the steering wheel. The contact stated that he would correct the steering and the vehicle would continue to drift to the right and to the left.
Steering · 2022-05-11 · NHTSA complaint #11464285

When owners complained

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

20075
20086
20093
20108
20116
20125
20138
20146
20156
20166
20184
20194
20203
20215
20221
20231
20251
20262

Comparison

By complaint count this model year ranks 4,081 of 36,656 model years in the NHTSA data (top 11% most complained about).

On average one model year of the Grand Marquis has 117 complaints (34 years in the data). This year has 80, below average.

What to check before buying

Steering. Steering play, power assist, rack and tie rods after a wheel impact.
Vehicle speed control. Accelerator pedal, cruise control, throttle codes.
Service brakes. Pedal feel, ABS operation, leaks, discs and hoses.
Electrical system. Scan all modules, test the battery and alternator, inspect connectors near the impact zone.

Other years of this model

Questions and answers

What are the most common problems with the 2008 Mercury Grand Marquis?

Owner complaints to NHTSA most often mention: steering, vehicle speed control, service brakes. Total complaints: 80. The most frequent symptoms in complaint texts: unintended acceleration (11%), steering or power steering problems (10%), warning lights, check engine (8%).

How many service bulletins (TSB) were issued for the 2008 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 2008 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 2008 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.