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really awful
Typical Repair Cost:
No data
Average Mileage:
48,000 miles
Total Complaints:
1 complaints

Most Common Solutions:

  1. not sure (1 reports)
2003 Mercury Grand Marquis engine problems

engine problem

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2003 Mercury Grand Marquis Owner Comments

problem #1

Oct 262013

Grand Marquis Limted 4.6L V8

  • Automatic transmission
  • 48,000 miles


3 times during a local errand run of 6 miles , then engine redlined by itself as the car was coming to a stop. The first time, the car launched into the intersection as I approached the light. The engine raced to full RPM causing the rev limiter to kick in. I had to turn off the ignition because the car would not idle. I barely had enough strength to hold the brakes on as the rear tires were spinning. The second time, again, was as I was coming to a stop, the car launched forward at full throttle. The third time was when I went to start the car and it happened again while the car was in park. There is no floor mat in the car, that was the first thing we checked. An ASE certified mechanic said it could not be the IAC because faulty IACs will not make the car REDLINE. We disconnected the Cruise control plug from the module because it was the only thing we could see that affects the throttle control.

- , Miami, FL, USA

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