Note. Recommended interval: every 100,000 km or 48 months.
Note. When checking and adjusting valve clearances on vehicles manufactured before 1998, a special tool is required to retract the valve lifters.
Clearance check
Disconnect the wire «masses» from the battery.
Remove the high-voltage wire leads or ignition coils from the spark plugs and move them away from the cylinder head cover.
Clean the area around the spark plugs with a compressed air jet to prevent dirt from entering the engine cylinder after the spark plugs are removed. Remove spark plugs.
Remove the cylinder head cover.
Turning the engine crankshaft in the direction of its working rotation by the pulley mounting bolt, set the piston of the first cylinder to top dead center (TDC) at the end of the compression stroke.
Pic. 2.48. Measurement of exhaust valve clearances in cylinders 1 and 3 and inlet valve clearances in cylinders 4 and 2 when the piston of the 1st cylinder is set to TDC
Use a feeler gauge to measure the exhaust valve clearance on cylinders 1 and 3 and the intake valve clearance on cylinders 4 and 2 (pic. 2.48, 2.49). Record the measurement results.
Pic. 2.49. Using a feeler gauge to measure valve clearances
Pic. 2.50. Measuring exhaust valve clearances in cylinders 2 and 4 and intake valve clearances in cylinders 1 and 3 with the piston of the 4th cylinder at TDC
Rotate the crankshaft one turn (4th cylinder piston at TDC at the end of the compression stroke) and measure the clearances on the rest of the valves (pic. 2.50). Record the measurement results.
Gap adjustment
Note. On cars manufactured before 2001, shims are used to adjust valve clearances, and on cars manufactured since 2001, tappets with different thicknesses are used.
Cars up to 2001
If the valve clearances differ from the required values, adjust them.
Rotate the engine until the lobes of the camshaft above the valve requiring adjustment are pointing upwards.
Pic. 2.51. Installation of a special tool on the camshaft to sink the valve lifterg
Install the tappet pusher tool on the spark plug side of the camshaft above the tappet (pic. 2.51). Squeeze the handles of the tool, while the valve lifter will be recessed down, and install a stop between the edge of the pusher and the camshaft (pic. 2.52). Remove the special valve tappet tool. Use a screwdriver blade or tweezers to remove the adjusting washer and measure its thickness with a micrometer.
Pic. 2.52. Fixing the valve lifter with a stop installed between the edge of the pusher and the camshaft, and removing the shim
Production vehicles since 2001
Pic. 2.53. Measuring the thickness of the pusher head with a micrometer on cars manufactured since 2001
If the valve clearances differ from the required values, remove the camshaft (or camshafts) and pushers. Using a micrometer, measure the thickness of the pusher head (pic. 2.53).
All models
Determine the thickness of the new shim or pusher head using the formula:
N = T + (A - V),
where A is the measured gap, mm;
N is the estimated thickness of the new shim or pusher head, mm;
T - thickness of the removed adjusting washer or pusher head, mm;
V is the nominal gap, mm.
Choose a shim or tappet with a thickness closest to the design.
Spare parts are supplied with shims 2.5 to 3.3 mm thick in 0.05 mm increments and tappets 5.060 to 5.740 mm thick in 0.020 mm increments.
Cars manufactured before 2001
Rotate the engine until the lobes of the camshaft above the valve requiring adjustment are pointing upwards.
Install the tappet pusher tool on the spark plug side of the camshaft above the tappet (pic. 2.51). Squeeze the handles of the tool, while the valve lifter will be recessed down, and install a stop between the edge of the pusher and the camshaft (pic. 2.52). Remove the special valve tappet tool. Use a screwdriver blade or tweezers to remove the shim if it has not been removed previously. Install a new washer instead. Reinstall the special valve tappet tool. Squeeze the handles of the special tool and remove the stop.
Use a feeler gauge to measure the valve clearance.
Repeat the steps to replace the shims on the remaining valves requiring clearance adjustment.
Production vehicles since 2001
Install the pushers with the estimated thickness of the head, after lubricating them with engine oil. Also apply a coat of oil to the inside of the pushrod that contacts the valve stem.
Install the camshaft (camshafts).
All models
Install the cylinder head cover, screw in the spark plugs and connect the high voltage wires or ignition coils to them.