Marine diesel engine parts L23/30 cylinder head

Removal and installation of engine cylinder head

1. Description

(1) When installing a cylinder head with camshaft, oil must be applied to the contact surface of the tappet and camshaft.

(2) Before installing the cylinder head, remove the plastic gasket that protects the valve. The gasket was brought on delivery.

(3) When replacing the cylinder head, all coolant must be updated.

2. Disassembly and assembly conditions: The engine is cold

3. Disassembly steps

(1) Turn off the ignition switch and remove the battery ground wire. Drain the coolant and unplug the coolant hose from the connecting pipe on the cylinder head.

(2) Remove the upper part of the intake manifold, and block the water inlet pipe on the cylinder head with a clean rag.

(3) Remove the spark plug plug and loosen the clamp of the high-voltage ignition wire and the protective plate of the fuel injection valve.

(4) Unplug the Hall sensor, coolant temperature sensor, air conditioner thermal switch, and fuel injection valve plugs.

(5) Loosen the wire clamp of the fuel distributor and pull out the vacuum hose on the fuel pressure regulator. Note: The fuel pipeline is under pressure. Before loosening the hose joint, place a rag on the pipe joint and slowly unplug the hose to relieve the pressure;

(6) Unplug the fuel supply and return hoses from the fuel distributor, and remove the wiring harness bracket and connecting pipe/coolant pipeline on the cylinder head. Unscrew the front exhaust pipe from the exhaust pipe joint.

(7) Tighten the central screw at the end of the toothed belt pulley in the direction of engine rotation, and remove the upper guard of the toothed belt.

(8) Remove the toothed belt from the camshaft timing gear.

(9) Remove the cylinder head cover, loosen and unscrew the cylinder head bolts in order, and gently remove the cylinder head.

4. Installation steps

(1) Put a clean rag into the cylinder to prevent dirt from entering the cylinder wall and the piston. At the same time, do not allow dirt to enter the coolant.

(2) Clean the sealing surface of the cylinder head and cylinder body, and be careful not to form elongated small grooves or scratches (using sandpaper with a particle size of not less than 100).

(3) Wipe off the grinding residue carefully with a rag.

(4) Set the first cylinder piston at the top dead center and rotate the crankshaft in reverse.

(5) Lay the cylinder gasket: pay attention to the positioning pin shown by the arrow; pay attention to the installation position of the gasket, and read the part number on the intake side.

(6) Install the cylinder head.

(7) Install the cylinder head bolts and tighten them by hand.