The Ford F-150 Lightning was produced between 1993 and 1995, then again from 1999 through 2004. The engine is a 5.4-liter, supercharged engine. The valve cover gaskets need to replaced when they start leaking oil. Because of the extra pressure on the crankcase, caused by the supercharger, don't be surprised if the valve cover gaskets need to be replaced sooner than in a non-supercharged F-150. You must remove the upper intake manifold to get the valve covers off.
Take the vehicle to a certified repair shop to have them discharge the Freon from the air-conditioning system. Let them know that you will need to recharge the system -- ask up front what the charge will be, and make sure that they don't charge you for the Freon, if there is Freon in your system --- they will charge you for the labor, though.
Locate the fuel pump relay in the relay box. The relay box is located near the driver's side fenderwell. Pull the fuel pump relay, as shown by the diagram on the underside of the cover, out of the relay box. Crank the engine over --- it might start --- a few times. If it does start, let it run until it stalls, to release the pressure in the fuel system.
Place the drain pan under the radiator petcock. Open the radiator cap, then open the petcock and allow the coolant to drain into the drain pan. Loosen the accessory drive belt tensioner, using the appropriate socket, by turning the tensioner away from the belt. Lift the belt off the pulleys.
Remove the wiring from the back of the alternator, using a wrench for the power wire. Unplug the wiring harness connector. Remove the alternator retaining bolts, then remove the alternator from the engine. Loosen the clamps on the air cleaner duct, pull the ductwork off the engine and air cleaner box, then unbolt and remove the air cleaner box.
Loosen the clamp on the upper radiator hose at the thermostat housing, using the screwdriver. Pull the hose off the thermostat housing. Loosen the clamp on the heater coolant hose on the bypass tube. Pull the hose off the bypass tube. Disconnect the quick-connect coupling on the evaporative emissions (EVAP) tube where it attaches to the manifold. Pull the EVAP tube off the intake. Disconnect the quick-connect coupling on the PCV tube, and remove the PCV tube from the valve cover. Disconnect the fuel supply spring lock coupling on the fuel rail.
Disconnect the electrical connectors on the fuel rail pressure temperature sensor and the vacuum connector, both located on the intake. Disconnect each of the eight fuel injector connectors. Unplug the throttle position sensor and the electronic throttle control wiring harness connectors. Unplug the heated PCV element connector. Loosen the clamp on the brake booster vacuum house on the intake, then pull the hose off the intake. Remove the 10 upper intake manifold bolts.
Remove the coolant bypass tube, using the appropriate socket, and discard the gaskets. Clean the gasket mating surfaces with a plastic scraper. Disconnect the charge motion control valve's electrical connector. Disconnect the intake manifold's vacuum tube from the valve cover stud and support bracket. Unplug the cylinder head temperature sensor jumper harness connector. Unplug the left and right knock sensor electrical connectors. Remove the nut that holds the wire on the charge motion control valve, then pull the wire off.
Remove the intake manifold. Clean the gasket mating surface on the upper and lower intake manifolds with a plastic scraper and rags. Disconnect the EGR tube from the exhaust manifold, using the appropriate wrench, then remove the valve and tube as an assembly. Pull the crankcase ventilation hose out of the valve cover. Unbolt the power steering reservoir bracket, then set both aside, making sure the reservoir is positioned so that the fluid doesn't leak out.
Remove the dipstick tube bracket bolt and push the tube out of the way. Unbolt the ignition coil cover, using the appropriate socket. Unplug the four ignition coils, then unbolt and remove the coils. Label the spark plug wires by numbering them, so you know where they go when you put them back on. Pull the wires off the spark plugs, then remove the spark plugs using the appropriate socket.
Unbolt and remove the driver's side valve cover. Scrape all gasket debris off the valve cover and head, making sure none falls into the head. Coat the valve cover with a thin layer of RTV silicone. Allow it to set for two minutes, then press the valve cover gasket onto the valve cover. Apply a 1 mm bead of RTV to the flat part of the mating surface on the backside of the head. Position the valve cover in place, then install the bolts. Tighten the bolts to 89 inch-pounds of torque.
Remove the PCV valve and hoses from the passenger side valve cover. Unbolt the cables from the starter solenoid, using the appropriate wrench. Unbolt and remove the bulkhead connector bracket bolts. Move the bracket and harness to the side. Unplug the wiring connector on the air conditioning clutch cycling pressure switch. Remove the nut, using a wrench, to disconnect the air-conditioning hose from the suction accumulator. Disconnect the suction accumulator hose from the evaporator core. Loosen the suction accumulator clamp, then remove the suction accumulator from the vehicle. Loosen the clamps on the heater hoses at the heater core, then pull the hoses off the heater core and set them aside.
Remove the nut on the wiring harness bracket near the rear of the valve cover, then move the harness aside. Remove the nut holding the air conditioning muffler on and move the muffler out of the way. Loosen the clamp on the heater hose on the front of the engine, then pull the heater hose off. Remove the transmission dipstick tube bolt and turn the tube out of the way. Unbolt the ignition coil cover, using the appropriate socket, and remove it.
Disconnect the four ignition coils on the right side of the engine, then remove the coils. The wires should already be numbered and removed from the spark plugs. If not, number them now, and pull them off the plugs, then remove the plugs. Remove the wiring harness connector form the valve cover studs. Remove the valve cover bolts and studs, then remove the valve cover. Clean the mating surfaces with a plastic scraper and rags.
Smear a thin layer of RTV silicone on the valve cover's mounting surface. Wait two minutes, then press the gasket onto the valve cover. Put a 1 mm bead of RTV on the flat parts of the head's mating surface. Allow the RTV to skin over -- when you touch it, it should not stick to your finger. Place the valve cover onto the head and install the bolts. Tighten the bolts to 89 inch-pounds of torque.
Apply a thin layer of RTV silicone to the intake manifold mating surface. Allow it to set for two minutes. Press the intake manifold gaskets into the RTV. Fit the intake onto the lower intake manifold. Position the coolant crossover and install the three bolts. Tighten them to 89 inch-pounds of torque.
Insert the 10 intake manifold bolts and tighten them as far as you can by hand. Starting with the middle bolts and working your way out, alternating from left to right in an X pattern, tighten the intake manifold bolts to 18 inch-pounds of torque. Repeat the process, this time tightening the bolts to 89 inch-pounds of torque.
Replace the rest of the parts in reverse order of removal. Plug in all wiring connectors. Reconnect all the hoses and tighten the clamps. Close the petcock on the radiator. Refill the radiator with 50/50 antifreeze. Start the vehicle to check for water and oil leaks. Go back to the shop to have the Freon refilled.
