Changing the Timing Belt in a Mercury Mystique

The 1998 through 2000 Mercury Mystique comes with a 2.0L engine, which is an interference engine. Should the timing belt stretch past the scope of the tensioner, the valves will most likely hit the pistons and cause extensive engine damage. Mercury has not recommended a specific interval to change the timing belt, but previous use and service history dictates that the belt has ended its useful life at about 60,000 miles. To prevent engine damage, the belt should be changed every 60,000 miles. The procedure uses two special tools, both available at any Mercury dealership.

Tools You Need:

Set of wrenches
Floor jack
Jack stands
Lug wrench
Set of sockets
Camshaft alignment tool No. 303-465
Allen wrench
Crankshaft timing pin No. 303-574
Torque wrench

STEP 1: Disconnect the battery ground cable using a wrench and lay it aside, ensuring that it does not touch metal. Jack up the front of the Mystique with the floor jack, then support it with jack stands. Remove the right front wheel using the lug wrench. Remove the lower splash guard and the right inner fender lower splash guard using the appropriate sockets.

STEP 2: Mark the direction of rotation of the accessory drive belt by drawing an arrow on it. Push the accessory drive belt tensioner away from the belt using a socket or wrench, to loosen tension on it. Lift the belt off the pulleys.

STEP 3: Remove the water pump pulley and the accessory drive belt tensioner using the appropriate sockets. Loosen the crankshaft pulley bolt. Turn the crankshaft clockwise until the notch in the pulley and the pointer is lined up at the 5 o'clock position (these are the timing marks). Remove the crankshaft pulley bolt and the crankshaft pulley, ensuring that you do not move the crankshaft while removing the pulley. Remove the timing belt lower cover using the appropriate socket.

STEP 4: Loosen the bolts for the left and right engine mounts. Lower the Mystique off the jack stands. Move the coolant expansion tank out of the way (leave the hoses connected). Disconnect the cruise control cable, located on the throttle body, using the appropriate sockets. Support the engine with the floor jack--just jack it up enough to touch the bottom of the oil pan.

STEP 5: Remove the front engine mount, the power steering pipe bracket, the upper timing belt cover and the front engine mount bracket using the appropriate sockets. Disconnect the accelerator and cruise control cables from their holders on the valve cover. Remove the spark plugs cover.

STEP 6: Number the spark plug wires so you know where they go when you put the Mystique back together. The No. 1 cylinder is closest to the timing belt, and the cylinders are numbered 1 through 4. The firing order is 1-4-3-2. Remove the valve cover using the appropriate socket.

STEP 7: Install the camshaft alignment tool into the slots at the rear of the camshafts. Loosen the tensioner retaining bolt, then turn the tensioner clockwise using the Allen wrench. Unscrew the tensioner retaining bolt four turns. Unhook the tensioner bracket from the metal clip. Remove the plug from the camshaft sprocket.

STEP 8: Put a wrench on the hexagon on the camshaft to hold the camshaft. Use another wrench or socket to remove the loosen the camshaft sprocket bolts. Lift the timing belt off the sprockets and pulleys.

STEP 9: Install the crankshaft pulley temporarily. Make sure the timing marks are lined up and that the camshaft alignment tool is still firmly installed. Remove the plug from the cylinder block, then install the camshaft timing pin (located near the crankshaft pulley). Adjust the position of the crankshaft until it rests against the timing pin. Remove the crankshaft pulley. Make sure the timing marks are still lined up. Make sure the tensioner bracket is unhooked from the metal clip.

STEP 10: Install the new timing belt in a counterclockwise direction, starting on the crankshaft sprocket. Keeping the timing belt taut on the non-tensioned side, route the timing belt behind the lower guide pulley (if equipped, models after 6/99 do not have this pulley), behind the upper guide pulley, over the right camshaft (as you are looking down at the engine), over the left camshaft, then down behind the tensioner pulley. Make sure the crankshaft is still against the pin.

STEP 11: Hook the tensioner bracket into the metal clip. Turn the tensioner counterclockwise using an Allen wrench, until the pointer is lined up with the mark. Hold the tensioner in place, and tighten the tensioner bolt to 18.5 foot-pounds of torque. Remove the Allen wrench.

STEP 12: Put a wrench on each of the hexagons of the camshafts to prevent the cams from turning. Tighten the intake sprocket (right side, looking down at the engine) retaining bolt to 50 foot-pounds of torque. Tighten the exhaust sprocket retaining bolt to 44 foot-pounds of torque. Remove the crankshaft timing pin and the camshaft alignment tool. Hold the exhaust camshaft, using a wrench on the hexagon. Tighten the exhaust sprocket retaining bolt to 89 foot-pounds of torque.

STEP 13: Turn the crankshaft clockwise, slowly, almost two turns. Install the crankshaft timing pin. Turn the crankshaft clockwise until it touches the timing pin. Insert the camshaft alignment tool, to ensure that it easily fits into both camshaft slots. If it does not go in easily, repeat the entire installation and tensioning process.

STEP 14: Remove the timing pin and camshaft alignment tool. Install a new plug into the camshaft sprocket. Tighten the plug to 27 foot-pounds of torque. Install the block plug and tighten it to 18.5 foot-pounds of torque. Install the rest of the parts in reverse order of removal. Tighten the crankshaft pulley bolt to 85 foot-pounds of torque.