How to Replace the Intake Manifold in a Nissan Pathfinder 2.4L

The 2.4 L Pathfinder was only made for a few years.

The Pathfinder is a long-running SUV sold by the Japanese auto manufacturer Nissan. Pathfinders produced between 1986 and 1989 had a base 2.4 L four-cylinder engine and an optional V-6. Although the 2.4 L engine would continue to be featured in other Nissan vehicles, such as the Frontier truck, it was discontinued in the Pathfinder.

Difficulty:

Challenging

Instructions

Things You'll Need

• Pliers
• Drain pan
• Socket wrench
• Torque wrench
• Replacement intake manifold gasket

1. Remove the gas cap and the fuel pump relay from the engine bay fuse box. Crank the engine to relieve the fuel system pressure. Let the engine sputter and shut off. The fuel system is under intense pressure, which must be relieved prior to removing the intake manifold.

2. Disconnect the negative battery cable for safety. Place the drain pan under the radiator and remove the coolant drain plug from underneath. Allow the engine coolant to completely drain. Cover the engine coolant and keep it in a safe place, away from animals and children.

3. Remove the radiator hoses from the intake manifold. Cover the opening of the hoses to prevent contaminants from entering the system. Remove the throttle cable assembly from atop the manifold.

4. Disconnect the fuel pipe connected to the intake manifold and the fuel return line. Be careful when doing so; a small amount of fuel will leak even after you have relieved the fuel system pressure. Cover the opening of the lines, if possible, to prevent leakage.

5. Remove the EGR valve tube and the PVC valve tube from the back of the intake manifold. Remove any other tubes that may be attached. Label the tubes to prevent connecting them to the wrong pipe. Remove the intake manifold support bracket.

6. Unbolt the intake manifold and remove it along with the fuel rails. Remove the fuel rail and injectors from the manifold unless you plan on installing a new fuel rail. Remove the old intake manifold gasket from the mount. Thoroughly clean the mounting area.

7. Attach the fuel rail to the new intake manifold, unless you are using a new one. Mount the intake manifold and new gasket to the mount. Tighten the bolts by hand to have the entire system quickly attached. Once the manifold is attached, tighten each bolt to between 12 and 15 foot-pounds of torque. Go over the bolts a second time after the initial tightening to double-check.

8. Reattach all tubes you removed from the manifold. Reattach the intake manifold support bracket. Reconnect the main fuel line and the return fuel line. Replace the throttle cable assembly. Reattach the radiator hoses to the intake manifold.

9. Make sure you replace the drain plug before refilling the coolant. Refill the engine coolant, being very careful not to spill it. Replace the gas cap and the fuel pump relay. Reconnect the negative battery cable. Start the engine and check underneath for coolant or fuel leaks.

Tips & Warnings

• Replacing the intake manifold is better suited for a mechanically inclined individual, or someone with some experience working on cars.

• Be sure to follow all safety procedures, including relieving fuel system pressure and properly storing the coolant.

References

• Nissan 2.4 Repair Guide