How to Change an 2004 Ford F150 Exhaust Manifold

The cylinder head on your Ford F 150 engine is subject to very high temperatures and pressure from the combustion chambers. After a period of time, the exhaust gaskets may break and cause engine performance problems. If one of the exhaust manifold gaskets has cracked, replace both gaskets at the same time. This guide is based on a 4.6L engine model.

Difficulty: ModerateInstructionsThings You'll Need:

Floor jack and 2 jack standsWrench setRatchet and socket setPlastic scraper and gasket remover solventGasket adhesive

Step 1
Park your pickup truck in a safe place with enough room to work at the front of the vehicle. Set the transmission to neutral.
Step 2
Raise the truck using a floor jack and safely support it on jack stands. You might find it easier to work from underneath the vehicle to remove certain components.
Step 3
Remove the left-hand, driver-side inner fender and disconnect the exhaust Y-pipe flange from the left-hand exhaust manifold by removing the two nuts. Move the pipe to the side. Use a wrench, ratchet or sockets as appropriate.
Step 4
Remove the line from the exhaust gas recirculation (EGR) system module connected to the exhaust manifold.
Step 5
Remove the left exhaust manifold. Take note of the nuts order on the exhaust manifold so that you install each one at the same place.
Step 6
Remove the gasket and all traces of gasket material from the mating surface of the engine head and exhaust manifold.
Step 7
Install the new gasket. You may use gasket adhesive to hold the gasket in place during installation.
Step 8
Install the exhaust manifold. Start with the nut at the top and back of the manifold and then the one at the bottom. Do not fully tighten the nuts yet. Move on to the next set of two nuts, always starting at the top, until you have installed all eight manifold mounting nuts. Now, torque all the exhaust mounting nuts to 18 foot pounds (25 Nm) following the sequence described.
Step 9
Attach the Y-pipe to the exhaust manifold and torque the flange to 30 foot pounds (40 Nm). Then install the left-hand inner fender well.
Step 10
To replace the right-hand exhaust manifold gasket, follow the same procedure described for the left-hand exhaust manifold gasket replacement. In addition, you will have to remove the starter from the vehicle to give yourself room for manifold removal. Once you finish, lower the vehicle.