Fix It

The 1999 Mercury Cougar has two engine options. The base engine is a 2.0-liter, in-line four-cylinder, which produces 130 horsepower. The optional engine is a 170-horsepower 2.5-liter V-6. No matter the engine size, the 1999 Cougar has an on-board diagnostic (OBD) computer with an OBD-II port.

Location

The OBD-II port is sometimes difficult to find on certain vehicles. However, the Cougars OBD-II diagnostic port is easy to find. It is located on the drivers side, under the dashboard and to the drivers side of the steering wheel.

Function

The OBD-II port is where an OBD-II scanner can be plugged in. This scanner gathers all of the information from the vehicles computer and displays it on a screen. Some computers even have testing functions for certain components.

History

On-board diagnostics started back in 1982 in California when the California Air Resources Board began creating regulations that required all vehicles to have an on-board diagnostic system -- now known as OBD-I -- to sense emission system failures. In 1996 the Federal Government followed suit by making the more-universal OBD-II required on all vehicles.

Like most parts on your 96 Mercury Mystique, the thermostat will eventually need to be replaced. Because of its location, and because it has coolant or water constantly running through it, the thermostat will rust or break down over time. Fortunately, the part was designed to be disposable. Once it has worn out, you can simply discard it and install a new one in its place.

Instructions

1

Use your ratchet and socket set to disconnect the negative battery cable from the battery.

2

Follow the large radiator hose from the upper-right portion of your radiator to where it connects into the engine block. This is the water outlet. Your thermostat is located beneath the outlet.

3

Loosen the hose clamp on the small hose at the top of the water outlet, using your flat-head screwdriver. Pull the hose back and shove it out of the way to the side.

4

Place your small bucket under the large coolant hose. This is to catch any coolant that leaks out when you remove the hose.

5

Loosen and remove the hose clamp from the large hose, then pull the hose away from the water outlet. Some coolant will leak out at this point, so be prepared.

6

Use your ratchet and socket set to loosen and remove the three retaining bolts securing the water outlet to the engine block, then pull the outlet off of the engine to reveal the thermostat.

7

Remove the thermostat from the thermostat housing and discard.

8

Use your razor blade and scouring pad to clean off the thermostat housing and the bottom of the water outlet. The old thermostat gasket will likely have partially disintegrated and will need to be scoured off.

9

Apply a layer of gasket sealant to the newly-cleaned area around the thermostat housing, then place the new gasket into the sealant.

10

Place the new thermostat into the thermostat housing in the exact same position as the old one.

11

Replace the water outlet and secure it down with the three retaining bolts.

12

Replace the hoses and tighten down the hose clamps. Pour any coolant you collected back into the radiator and re-connect the battery cable.

The 1999 Mercury Sable model enjoyed some early positive reviews, but major problems would later be reported on some models with the brakes, engine and various accessories. Smaller issues were also reported with other areas of the vehicle, including the transmission. As of 2010, the Ford Company is dropping the Mercury line of cars, including the Sable.

Leaking Fluid

In some models there were early problems with leaking transmission fluid well before any part of the car should be worn down. A variety of causes can trigger this problem, from loose hoses to improper fastening. This was not a common enough problem to warrant a recall or widespread announcement, but enough early repairs were made to note this as a potential problem in 99 Sables.

Front Pump Issues

Problems with the front pump in the 1999 Sable were often chalked up to an engine issue, although it affects the transmission. The front pump is a part of the torque converter in automatic transmissions, and directly affects the mixture of air with transmission fluid. If the front pump isnt working properly, most often due to gunk or carbon build up from a lack of maintenance, the car will experience transmission issues and eventually wont even shift into gear. Repair costs can vary greatly, depending on the exact nature of the main problem with the front pump and whether the issue requires a simple cleaning or if an outright replacement is needed.

Engine Problems Affecting Transmission

Some of the most common problems reported on the 1999 Mercury Sable come from engine issues that affect other parts of the vehicle so that they in turn dont work properly. MSN Auto is one of many sources citing major reports of a variety of engine problems on the 1999 Mercury Sable. Since the transmission is the most complicated section of a modern car, any problem in another part of the engine can affect the transmission.