How to Replace the Exhaust Manifold in a Mitsubishi 3000GT

Remove the negative battery cable from the terminal. Drain the cooling system (see Warnings).

Take the turbocharger assembly from the engine and remove the heat shield. Apply penetrating oil to the exhaust manifold fasteners and let it soak in for several minutes.

Loosen the mounting nuts that hold the exhaust manifold in place. Remove the exhaust manifold from the engine. Notice the cone disc springs are installed at all the lower mounting points.

Clean the mating surfaces to remove any gasket material, dirt and carbon deposits. Wipe the surfaces with solvent. Check the mating surfaces for damage.

Set the new gasket on the mating surface of the cylinder head. Align the exhaust manifold over the gasket.

Make sure that the cone disc springs are in their proper (original) locations with the grooved side turned toward the nut. Set the manifold nuts in place and finger-tighten them.

Torque the manifold nuts as follows: tighten all except the two outer nuts to 22 foot pounds. Torque the two outer nuts to 34 to 38 foot pounds. Loosen the outer two nuts then and tighten them to 22 foot pounds.

Set the heat shield in place and secure it. Install the turbocharger assembly.

Fill the cooling system with the appropriate amount and type of coolant. Connect the negative cable to the battery terminal.

Start the engine and allow it to run for several minutes. Check for exhaust leaks and proper engine operation.