The cylinder head gasket is replaced if it is damaged

The main signs of damage to the head gasket:

  • - insufficient compression - below 1 MPa (10 kgf/cm 2) in one or more cylinders;
  • - breakthrough of gases into the cooling system (seething, foaming of liquid in the radiator, rapid drop in the liquid level in the expansion tank in the absence of external leaks);
  • – ingress of coolant into the lubrication system (emulsion on the oil level indicator, stratification of oil drained from the crankcase, especially noticeable in a transparent container);
  • - oil entering the cooling system (oil film on the surface of the liquid in the expansion tank).

To replace the gasket, you need to remove the cylinder head with the reservoir and exhaust manifold.

If the cylinder head is removed from the engine installed on the car, you must first drain the coolant (article - How to change the engine coolant).

You will need: keys "for 12", "for 13", "for 17", hexagons "for 6", "for 12", a screwdriver.

  • 1. Disconnect the wire from the negative terminal of the battery.
  • 2. Drain the cooling system.
  • 3. Remove the generator.

Replacing the ZMZ-409 cylinder head gasket

Remove the nuts securing the exhaust pipe to the exhaust manifold (Fig. 1).

Replacing the ZMZ-409 cylinder head gasket

Remove the bolt that secures the exhaust pipe to the bracket on the gearbox (Fig. 2) and move the exhaust pipe away from the exhaust manifold.

Replacing the cylinder head gasket ZMZ-409

Disconnect the wiring harness connector from the mass air flow sensor (fig. 3).

Replacing the ZMZ-409 cylinder head gasket

Disconnect the throttle position sensor harness connector (fig. 4).

Replacement of cylinder head gasket ZMZ-409

Disconnect the crankshaft position sensor harness connector (fig. 5).

Replacing the ZMZ-409 cylinder head gasket

Loosen the air pipe clamp, remove the pipe and move it to the side.

Replacing the cylinder head gasket ZMZ-409

Disconnect the end of the cable from the throttle actuator sector (fig. 7).

Replacing the cylinder head gasket ZMZ-409

Loosen the end of the cable sheath to the bracket (fig. 8).

Replacing the ZMZ-409 cylinder head gasket

Remove the end of the cable sheath from the bracket and move the cable to the side (Fig. 9).

Remove the cylinder head cover (article - Replacing the cylinder head cover gasket ZMZ-409).

Remove the upper chain tensioner

Remove the camshafts (article - Removing and installing camshafts ZMZ-409).

Replacing the ZMZ-409 cylinder head gasket

Disconnect the engine harness pads from the power unok (Fig. 10).

Replacing the ZMZ-409 cylinder head gasket

Unscrew the front nut securing the receiver (Fig. 11) and remove the “mass” wires from the studs.

Replacing the cylinder head gasket ZMZ-409

Disconnect the wiring harness connector from the idle speed control (fig. 12).

Replacing the cylinder head gasket ZMZ-409

Unscrew the rear nut securing the receiver (Fig. 13), remove the holder 2 of the fuel supply hose and the second “mass” wire 1 of the harness from the stud, and then set aside the wiring harness.

Replacing the ZMZ-409 cylinder head gasket

Loosen hose clamps 1 on the throttle assembly and disconnect hoses 2 and 3 (Fig. 14).

Replacing the cylinder head gasket ZMZ-409

Unscrew the nuts of the supply and drain fuel lines (Fig. 15) and move the lines to the side.

Replacing the ZMZ-409 cylinder head gasket

Remove the bolts securing the upper chain damper (Fig. 16) and remove the damper.

Remove the oil level indicator (dipstick).

Replacement of cylinder head gasket ZMZ-409

Remove the rightmost exhaust manifold nut (fig. 17).

Replacing the ZMZ-409 cylinder head gasket

Remove the coolant line bracket from the stud (fig. 18).

Replacing the ZMZ-409 cylinder head gasket

Sequence of tightening the cylinder head bolts (Fig. 19).

Replacement of cylinder head gasket ZMZ-409

Remove the bolts 1 (Fig. 20) securing the cylinder head in reverse tightening sequence, remove the cylinder head and remove the gasket.

Thoroughly clean the mating surfaces of the head and cylinder block from carbon deposits, remnants of the old gasket and sealant.

Lubricate the new gasket on both sides with a thin layer of graphite grease, and at the point of contact with the front cover of the block with heat-resistant adhesive-sealant.

Lay the gasket on the cylinder block, making sure that the locating sleeves of the block fit into the corresponding holes in the gasket.

Install the block head in the reverse order of removal.

Tighten the block head bolts in the order shown in fig. 19.

Tighten the cylinder head bolts in two steps:

  • 1st stage - 40–60 Nm (4.0–6.0 kgf m);
  • 2nd stage - 130-145 Nm (13.0-14.5 kgf m)

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