Many basic repairs can be performed without removing the engine from the vehicle.
Before starting any work, it is highly advisable to flush the engine compartment and engine with a jet of water. It is easier to work with a clean engine, and contamination of the internal structure of the engine is prevented.
To expand the workspace and not damage the paint, remove the engine compartment cover and mounted mudguards.
If traces of oil or coolant leaks are observed, indicating the need to replace gaskets, then all work is usually carried out without dismantling the engine. Without dismantling, you can replace the oil pan gasket, cylinder head, intake and exhaust manifold gaskets, front and rear covers, crankshaft oil seal.
Attachments such as the coolant pump, starter motor, alternator, ignition distributor, intake and exhaust manifolds, as well as the fuel pump and carburetor can also be removed without dismantling the engine.
Since the cylinder head can also be removed without dismantling the engine, repair of the valve mechanism is also possible.
Without dismantling, it is also possible to carry out such work as replacing or checking the condition of the toothed belt, camshaft drive gears, oil pump, front cover seal.
In extreme cases, when the necessary equipment is not available, piston rings, pistons, connecting rods and connecting rod bearings can be replaced without removing the engine, cylinders can be honed. However, it is not recommended to carry out these works without removing the engine, since cleaning of related parts and preparatory measures are required.