Loud Exhaust Noise from Your Jeep? Replacing an Exhaust Manifold on a Jeep 4.0L Engine

Replacing an exhaust manifold on a 4.0L Jeep engine, This engine is common in many jeep models including the Cherokee, Grand Cherokee and Wrangler vehicles.

Replacing the exhaust manifold requires that the intake manifold be removed also. The Jeep 4.oL engine design has the intake and exhaust manifold located on the same side of the cylinder head.

* The fuel system is under constant pressure. This pressure must be released before disconnecting.

1) Remove fuel filler cap to relieve tank pressure. Remove fuel pump relay from Power Distribution Center (PDC). PDC is located in the engine compartment near the battery. Start and run the engine until it stalls. Attempt to restart the engine until it will no longer kick over (or attempt to start).  Turn ignition off, this will lower the line pressure making it safer to remove fuel line later.

2) Disconnect the negative battery cable. Remove the air inlet tubing and air cleaner from the throttle body.

3) Disconnect throttle and cruise control (if equipped) cables. If your vehicle has a automatic transmission, disconnect the line pressure cable (kick down cable).

4) Unplug all electrical connectors from the intake manifold.

5)  Using a fuel line quick-disconnect fitting tool, disconnect the fuel line.

6) Loose the belt tenisoner and remove accessory drive belt.

7) Remove power steering pump and bracket. Use a strap to hold pump aside.

8 ) Remove fuel rail and injector assembly.

9) Disconnect exhaust pipe from exhaust manifold.

10) Remove manifolds retaining bolts, and remove intake and exhaust manifolds as a assembly.

11) Ensure all gasket surfaces are clean, Install New gasket.

12) Install exhaust manifold and tighten bolt No. 3 finger tight.

13) Install intake manifold and remaining bolts loosely.

14) Inspect fuel o-ring and replace as needed. Reconnect fuel line.

15) Tighten manifold bolts in proper torque sequence.

16) Reverse removal procedure to complete the remaining installation.

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