How to Replace the Exhaust Manifold on a 1997 Jeep Wranglerby Walt Sampson
Replacing the exhaust manifold on your 1997 Jeep Wrangler can save you money. Your 1997 Jeep Wrangler may be equipped with one of these four engines; a 2.4L or 2.5L four-cylinder engine, or a 4.0L or 4.2L six-cylinder engine. If you have a vehicle with a 2.5L, 4.0L or 4.2L engine, you will need to remove and reinstall the intake manifold as part of the exhaust manifold replacement.
Disconnect the battery negative cable using pliers to prevent inadvertent airbag deployment.
Prepare the vehicle for the replacement of the exhaust manifold by removing the intake manifold if you have a 2.5L, 4.0L and 4.2 L engine. (Refer to the Resources or other Jeep Wrangler repair books for directions on how to remove and replace the intake manifold.) Also, remove the exhaust gas recirculation, or EGR, tube from the exhaust manifold using a flare-nut wrench (open-ended wrench optional). Prepare a 2.4L-engine equipped vehicle by using a jack to place the front axle up on jackstands.
Spray the bolts that connect the exhaust manifold to the engine and to the exhaust pipe with penetrating oil. Remove the bolts and nuts that hold the exhaust pipe to the exhaust manifold using socket wrenches. Lower the front end of the 2.4L-engine equipped vehicle to the ground.
Remove the air filter housing bracket and the exhaust manifold heat shield on a 2.4L engine using socket wrenches. Disconnect the wiring harness from the oxygen sensor with your hand on a four-cylinder engine. Remove the oxygen sensor using an open-ended wrench.
Remove the bolts (2.4L engine), nuts (2.5L, 4.0L and 4.2L engines), and spacers (2.5L engine) that hold the exhaust manifold to the cylinder head. Remove the exhaust manifold. Remove the exhaust manifold gasket and clean any residue from the mating surface on the cylinder head.
Reinstall the oxygen sensor on the new exhaust manifold (four-cylinder engine) using a new oxygen sensor gasket. Install the new exhaust manifold on the engine using a new exhaust manifold gasket. Reinstall the attaching hardware and hand tighten the bolts or nuts.
Place a vehicle with a 2.4L engine back up on the jackstands. Connect the exhaust pipe to the exhaust manifold (any engine) and hand tighten the attaching hardware.
Torque the exhaust manifold bolts (2.4L engine) to 200 inch-pounds using a torque wrench. Note: Start at the center and alternate tightening the bolts out to the ends. Torque the exhaust manifold nuts to 23 foot pounds (2.5L, 4.0L and 4.2L engines). Note: Wait until the intake manifold is reinstalled to torque the exhaust manifold nuts. Torque the exhaust manifold to exhaust pipe attaching hardware to 21 foot-pounds (all engines).
Lower the front end of the 2.4L-engine vehicle to the ground.
Reinstall all parts removed during the replacement of the exhaust manifold. Reconnect the battery negative cable. Start the engine and look for exhaust leaks.
Things You'll Need
- Flare-nut wrench (open-ended wrench optional)
- Penetrating oil
- Socket wrenches
- Open-ended wrenches
- Exhaust manifold
- Oxygen sensor gasket
- Exhaust manifold gasket
- Torque wrench
Walt Sampson has written technical manuals and corporate proposals since 1970. He has written for "The Denver Post" and "The Arizona Republic." Energy-conservation awards led to writing for professional magazines. Sampson has engineering degrees from the Naval Academy and the University of Michigan, and a Master of Christian Studies from Regent College.