Which parts fail
Components named in complaints (engine, cooling system, oil leaks, timing chain, exhaust).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2000 Mercury Grand Marquis owners, lightly cleaned up (personal details are redacted by NHTSA).
I believe this issue effects millions of Ford and Mercury vehicles, many of which are taxi, government, and police cars. Apparently, the computer (PCM) that controls the engine can shut the engine down while the vehicle is driving when certain sensors fail (at least 2 known sensors per my research). I found this out at 65 MPH, 2 hours from home. I was told by the dealer that there are no new pcms made for my 2000 car, and that I had to rely on a rebuilt after market PCM. The aftermarket seller related that these computers last approximately 10 years. Even if I replace this part, I believe this effectively makes my (and any such) car a risk to drive, as most rebuilt auto parts are created by simply replacing any failed components out of the many components in the assembly of the part, and leaving others still old and worn. …
A spark was blown out of the cylinder head. The problem occurred 3 times (2010, 2014, 2014), each time a different cylinder. One of these times, it occurred to my wife 140 km away from home. I had to guess that it was a blown spark plug and instructed her to drive the car to toronto in this condition. Concern: aside from the costly repair, I am afraid to use the car on a long trip for fear that this will happen at a place where a repair is not available. I suspect that the Ford company has modified the engine along the way, considering the fact that on a previous model I had owned for a long time (1993 Grand Marquis), the problem had never occurred.
Tl contact owns a 2000 Mercury Grand Marquis. The contact stated the he smelled a burning odor. The contact looked at the temperature gauge which indicated that the vehicle had overheated. The vehicle was taken to an independent mechanic where the contact was informed the intake manifold was made of plastic and was leaking. The leak was sealed, but the contact was informed that the repair May not hold up for a long period of time. The failure mileage was 100,000 and the current mileage was 103,000. The VIN was unavailable.
Tl* the contact owns a 2000 Mercury Grand Marquis. While driving various speeds, the vehicle hesitated to accelerate. The failure occurred most frequently when traveling up hill. The failure was intermittent and the check engine warning indicator illuminated. The dealer was not notified. The vehicle was not diagnosed or repaired. The contact sprayed carburetor fluid on the intake manifold and noticed a crack. The manufacturer was made aware of the failure. The failure mileage was 118,000.
I bought this car to replace my Chevrolet caprice(great car) on 719 07 this car has major issues that Ford motor company refuses to address. July 2011 fuel tank filler neck rusted causing a fire hazard dec20 11 rear axle control arm cracked causing car to sway feb 2012 plastic intake cracked causing coolant to spray all over engine. Ford issued a recall for this I called the local Ford dealer about this they told me it expired so im stuck to repair the car myself front end parts not serviceable and wear out (no grease fitting to lube) this has been the worst car I have ever owned.
The cars started missing and running rough even after having a complete tune-up and after about week later it started all over and was taken into the Mercury dealership that found that the intake manifold was cracked and had to be replaced at our expense, which we just received a letter in the mail regarding a class-action lawsuit against Ford for the same problem. I do believe that this needs to be followed up and Ford needs to refund all expenses due to the customers. Please check into this situation, we also have a friend who has had the same problem and had to have his replaced. Thank you
Tl* the contact owns a 2000 Mercury Grand Marquis. The contact stated that the thermostat was leaking. The thermostat was replaced however, the intake manifold failed and fell into the thermostat after the replacement. Additionally, there was a leak in the sensor coolant temperature sensor area which was repaired with a sealing solution and the thermostat was replaced because the plastic inside the intake manifold was deteriorated. The defect was not repaired or diagnosed. The current mileage was 170,000. The approximate failure mileage was 50,000.
Car started running hot all of a sudden..found out the intake manifold was cracked and the coolant was leaking on spark plugs and fuel injectors. Causing the car to misfire and slow to pick up speed. Tried to get fixed but was told the exp. Date was in 07.so I have to pay out of pocket..I feel a recall shouldn't have an expiration date cause it tells you that one of these days the part on the car is going to need to be fixed. I feel Ford should live up to their word and fix the problem no cost to customer...
Tl* the contact owns a 2000 Mercury Grand Marquis. The contact stated that the vehicle overheated while driving 35 MPH. The contact noticed fluid leaking from underneath the vehicle. The contact took the vehicle to a local mechanic where it was found that there was a coolant leak. The mechanic stated that there were three cracks on the intake manifold. The mechanic replaced the intake manifold. The failure mileage was 132, 208. Updated 05/29/13 updated 06/13/2013
Vehicle was going about 35 MPH when all of a sudden it started shaking. Then, lost its traction control, and caused the lights in the dashboard to turn off. This eventually LED the engine to shut off, and the driver lost steering. Taken to dealer for a checkup, but the results showed that the cause was undetermined. Car shuddered, followed by engine shut down resulting in loss of power brakes and steering.
NHTSA investigations
Spark plug ejection from cylinder head
On September 6, 2005, odi received a petition requesting that the agency investigate allegations of engine spark plug ejection in certain model year 1997 through 2004 Ford vehicles with triton v-8 and v-10 engines.odi received a total of 474 non-duplicative complaints on the subject vehicles where the complainant, or the dealer repairing the vehicle, reported that a spark plug detached from the cylinder and/or…
Engine complaints in other Grand Marquis years
Frequently asked questions
How common are engine problems on the 2000 Mercury Grand Marquis?
NHTSA has 25 complaints about the engine & cooling of the 2000 Mercury Grand Marquis, 15% of the model year's 162 complaints. The component named most often is engine (4 mentions).
Is there a recall for 2000 Mercury Grand Marquis engine problems?
No. NHTSA lists no engine & cooling recall for the 2000 Mercury Grand Marquis, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2000 Mercury Grand Marquis engine problems start?
Half of the complaints with a recorded mileage happened before about 87,000 miles, and 6% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 2 fires and 0 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.