Whether you have a Hyundai Accent, Sonata or Elantra the process to change a head gasket is similar, except the loosening and tightening sequence for the cylinder head bolts may differ. Regardless of the sequence, you will have to remove and separate most of the car parts near the top section of the engine. The head gasket sits beneath the cylinder head and above the engine block.
Start replacing the head gasket when the engine is cold. Slide a clean drain pan under the radiator drain plug to allow the coolant to drain. You need to unscrew the drain plug with pliers. Detach the battery cables. Drain the motor oil into another clean drain pan. Relieve the fuel system pressure.
Separate, unfasten, glide off or remove the mounting bolts, caps, belts, assemblies, covers, and other components near the top portion of the engine, including accelerator, cruise control cable, spark plugs, intake air duct, distributor, accessory drive belts, engine covers and power steering pump. Print the name of the upper engine components on a label to help simplify the process when you reconnect or reinstall.
Disconnect the multiple tubes and hoses, such as the heater hose, upper radiator hose, hose, brake booster vacuum hose, bypass hose, evaporative emissions canister hose, lower radiator hose and intake air bypass valve tube.
Separate the electrical connectors, such as the idle air control valve connector, engine coolant temperature sensor connector, crankshaft position indicator connector, throttle position sensor, exhaust gas recirculation valve connector, intake air temperature sensor connector, manifold absolute pressure sensor connection, radiator fan switch connector, and engine oil pressure switch connector.
Set the engine to top dead centre by aligning the camshaft pulley with the crankshaft marks. Slip the timing belt off and take off the camshaft pulley.
Remove the cylinder bolts in the appropriate loosening sequence. The bolt numbers on the upper level in the loosening sequence for a 1.8-litre engine are 4, 8, 10, 5 and 1. In addition, the lower level bolt numbers are 2, 6, 9, 7 and 3. Raise the cylinder head and gasket from the vehicle.
Completely clean the gasket mating surface, engine block and cylinder block. Examine the area for dents, damage or leaks. Oil the new cylinder head bolts with clean motor oil. Lower the new gasket on to the engine block and align the dowel pins. Assure the number one cylinder of the engine is set to top dead centre.
Torque the new bolts in the correct tightening sequence. For the 1.8-litre engine, the cylinder head bolt numbers on the top level are 7, 3, 1, 6 and 10 and the bolt numbers for the lower level are 9, 5, 2, 4 and 8. Tighten to 26 foot-pounds and 75 degrees. Loosen the new bolts and retighten to 26 foot-pounds and an additional 75 degrees.
Return the Hyundai parts back in place beneath the hood in the reverse order of installation, including exhaust manifold, intake manifold, distributor, crankshaft pulley, timing belt cover, distributor, spark plug wires and accelerator.
Pour the coolant in the cooling system and refill the engine oil in the motor oil reservoir. Reconnect the negative battery cable. Turn the Hyundai on and allow it to run. Examine the vehicle for coolant or oil leaks.
Review the illustration in a Hyundai service manual to help identify the various car parts.