Preparatory work and list of repair procedures that can be performed without removing the engine from the vehicle

Clean the engine compartment and the external surfaces of the engine and transaxle using one of the wide range of special cleaning solvents. This treatment will prevent dirt from entering the engine.

If required by the nature of the work to be performed, the hood may be removed to provide free access to the components to be serviced (see Body section). Protect the fenders with special covers or simply old blankets to prevent accidental damage to the paintwork.

If suspected vacuum loss or leaks of oil, coolant, exhaust gases, etc. indicate the need to replace the relevant gaskets or seals, almost all of the listed procedures can be performed without removing the engine from the vehicle (in situ). This applies to replacing the intake manifold and exhaust manifold gaskets, the oil pan, the cylinder heads, and both crankshaft seals.

Removal, repair, and installation of external components and attached units such as the intake manifold, exhaust manifold, oil pan, water pump (see Cooling and Heating section), starter motor, alternator, ignition distributor (see Engine Electrical section), and fuel system components (see Fuel and Exhaust section) can also be performed in situ.

Since the cylinder heads can be removed from the engine without first removing the engine assembly, valvetrain repairs can also be performed directly on the vehicle. In addition, camshafts, timing belt, and timing gears are usually replaced in situ.

In an emergency, repair and replacement of piston rings, pistons, connecting rods, and crankshaft connecting rod bearings can be performed without removing the engine assembly. However, this option should not be used routinely due to the difficulties associated with maintaining cleanliness and performing the required preparatory procedures.