The Jeep Grand Cherokee had two engine options in the late '90s early 2000s. The first was a 4.0 liter "I" or straight six cylinder. It is also available with a 4.7 liter V-8 engine for higher performance applications. The intake manifold on the 4.7 liter has no approved repair procedure. If severe damage occurs to the intake manifold, you must replace it. When the intake manifold gaskets begin to leak coolant, they must also be replaced.
Disconnect the negative battery cable and remove the air filter housing and the air intake assembly. The following disconnections are located on the intake manifold: Disconnect the throttle cable and speed-control cables from the throttle body. Disconnect the electrical connectors from all sensors and controls on the intake manifold, noting where each connector attaches. Disconnect the vacuum brake booster hose and the vapor purge hose. Disconnect the speed control servo and positive crankcase ventilation hoses.
Remove the serpentine drive belt. Disconnect electrical connections from the generator. Unbolt the generator and move it away to have enough room to work. Disconnect the electrical connections to the air-conditioning compressor. Remove the retaining bolt in the compressor. Pull it away and place it to the side. Disconnect the wiring connecting to the ignition coil towers. The towers connect to the spark plugs. Unbolt the coil towers and remove them. Remove the retaining bolt from the upper oil dipstick tube retainer.
Connect the fuel pressure gauge to the Schrader valve on the fuel injector rail. The valve looks like a tire inflation valve. Place the drain tube in a container and push the button on the bleed-off valve. This releases the fuel pressure from the rail. Remove the fuel rail by unbolting it from the intake manifold and by removing the fuel-line fittings with an open-ended or tubing wrench. Remove the throttle body by removing the bolts in the mounting bracket.
Drain the cooling system until the coolant level is below the coolant temperature sensor level in the manifold. Bring the coolant level to about half full in the radiator to do this. Drain coolant into a clean pan to reuse it. Remove the right-side engine-lifting stud from the manifold. Remove the intake manifold retaining fasteners, using a socket and ratchet from the front and rear of the manifold first, working to the center of the manifold. There are 10 fasteners. Remove the intake manifold by lifting straight up and level from front to rear to clear the cowl, or the area behind the hood.
Install the manifold by placing gaskets on the intake runners of the manifold, where they meet the head of the engine. Swap over all sensors into the new manifold. Lower the new intake manifold onto the engine. Install the intake manifold retainers, tightening them from the inside working out. Reverse of the removal procedure to complete the installation.
