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 1999 Mercury Cougar owners, lightly cleaned up (personal details are redacted by NHTSA).
Tl* the contact owns a 1999 Mercury Cougar. While driving approximately 5 MPH approaching a stop, the vehicle idled and stalled without warning. In addition, the speedometer fluctuated. The failure recurred, especially when the heater was activated. The contact would have to turn the ignition key in order for the vehicle to turn back on and be able to be driven again. The vehicle was not diagnosed nor repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 98,000.
1999 Mercury Cougar seat back failure during rear-end collision. Cougar stalled on busy freeway ending in rear totaled car collision. The driver's seat went completely down and upon seats in the backseat. This was two defects. Injuries were neck and back pains, three bumps to the head resulting in two black eyes. My advice to all 1999 Cougar owners-get rid of the car, by way of junkyard-this is an extremely dangerous vehicle and one will not know until an accident happens.
Tl* the contact owns a 1999 Mercury Cougar. The contact stated that while driving 45 MPH, smoke started to emit from the engine and caught on fire. The contact mentioned that the fire extinguished independently. The vehicle was not taken to the dealer. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure and current mileage was 97,000.
Tl contact owns a 1999 Mercury Cougar. The contact stated that the engine revs very high and then the vehicle begins to jerk. The contact has taken the vehicle to the dealer on several occasions, but they have been unable to diagnose the cause of failure. The contact informed the manufacturer about the failure and mentioned that the dealer changed several parts. The manufacturer stated that there were no current recalls or service bulletins for this failure. The serpentine belt, throttle assembly, and vacuum tube were replaced, but the failure persists. The current and failure mileages were 183,000. The consumer stated believes dealer charged for unnecessary repairs, inaccurate diagnostics, and financial burden for car rentals and wants to be reimbursed all the outpocket expenses. Updated 09/05/07
Tl* the contact owns a 1999 Mercury Cougar. The contact stated that the check engine light illuminated upon starting the vehicle. In addition, the engine exhibited a loss of power. The vehicle was taken to an independent repair shop and the contact was informed that the catalytic converter needed to be replaced. The vehicle was repaired. The failure recurred approximately eleven months later. The vehicle was taken back to the repair shop and the contact was informed that the same repairs would be needed. The vehicle was not repaired. The manufacturer was made aware of the failure and the contact was informed that the vehicle was not included in the recall associated with NHTSA campaign id number 04v42100(fuel system, gasoline). The failure mileage was 125,000. Updated 03/14/12
3/21/05 vehicle taken to Lincoln Mercury driveability concern by>>( my wife)>>>check engine light on, they fond intake gaskets leaking vac & bank 2 also monitor are very active need tune up and plug wires and tires... My wife gave them all technical service bulletins diagnostic trouble codes po420 & po430 paper....also,told them 99-Mercury Cougar 2.5l engine stall and have inability to start car...they kept paper, and told her she need new battery cables!!!! Call manufacturer on TSB and recall, we was told there was no recall on our vehicle I.d. Number....etc........consumer reports used car buying guide fond recall ---99-00 Mercury Cougar with 2.5l v6 engine----natsa number #01i009000 please help.............
Tl contact owns a 1999 Mercury Cougar. The mechanic noticed oil leaking from the oil pan gasket onto the exhaust pipes. The mechanic stated that the oil pan gasket material was defective. The contact currently has to carry a fire extinguisher. The mechanic stated due to the failure a fire could occur at any time. The manufacturer stated that no recalls were issued and would not repair or replace the gasket. The current mileage is 45,000 and failure mileage was 33,000. The consumer stated the gasket materials used were not durable and soft enough. They must have experienced cracking due to temperature fatigue. Updated 10/11/07.
Engine light came on I thaugh it would be an electrical problem, it was not.the car would jump and accelerate when stoping at traffic lights and stopped traffic when I would press on the gas lightly. Dealership said it would be $2000. To fix. I did not extend my Ford warranty. They said there was a hidden warranty with the engin and that I would have to pay $500. He aslo said I couldn't have been anything I did, the engine was coming apart, that would be the manufaturer's fault. I wish I would have not baught this Cougar, its been nothing but problems and recalls. I have went to the dealership so many time I've lost count.
1. Car began to lose power and the steering wheel began to lock up and lights began flickering on the dash. 2. The car stalled in the fast lane on a busy freeway. The consequence was a small truck rear-ended the back of the car and it was totaled. One person had busted lip in truck and one in the car had busted forehead and blackened eyes with back injuries and the other one had back and stomach extreme pains and legs. 3. Nothing could be done at this point-the car always had problems. Too bad, I was not aware of all of the recalls--maybe that would not have helped either.
As soon as I bought the car used with 49000 it wouldn't start. Replaced the starter, still wasn't right. Had to replace the flywheel because the old and new starter never matched properly with flywheel. Then, the engine light came on. The EGR sensor was bad. Replaced the sensor. All of this within one month of owning the car. Then a few months later coolant light wasn't just coming on, but staying on, had to replace coolant tank due to shorting of the sensor in the tank. Now, six months after owning car, engine light is back on.
Engine complaints in other Cougar years
Frequently asked questions
How common are engine problems on the 1999 Mercury Cougar?
NHTSA has 70 complaints about the engine & cooling of the 1999 Mercury Cougar, 15% of the model year's 454 complaints. The component named most often is engine (26 mentions).
Is there a recall for 1999 Mercury Cougar engine problems?
No. NHTSA lists no engine & cooling recall for the 1999 Mercury Cougar, though it has 7 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 1999 Mercury Cougar engine problems start?
Half of the complaints with a recorded mileage happened before about 90,000 miles, and 6% before 25,000 miles.
Is it dangerous?
Owners linked 5 crashes, 1 fire and 6 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.