Contents: Examination ↳ Adjustment ↳
Checking and adjusting valve clearance
Examination
1. Checking and adjusting valve clearances should be done on a cold engine. To adjust the valve clearance, use adjusting washers with a thickness of 3.00 to 4.75 mm with a resolution of 0.05 mm. The valve clearance is checked with a feeler gauge between the rear of the cam and the tappet.
2. Disconnect the elastic crankcase ventilation hose from the cylinder head cover.
3. Remove the cylinder block cover, having first unscrewed 10 M10 bolts.
4. Turn the engine crankshaft by the pulley mounting nut (do not turn by the camshaft pulley) in the direction of its working rotation until both cams of cylinder 1 are turned with the working part of the cam upward.
5. Check the valve clearance of cylinder 1 by inserting a feeler gauge between the rear of the cam and the tappet.
6. Determine the type of valve being tested (inlet or outlet) and compare the measured clearance value with the required value. If necessary, adjust the clearance of the valve being tested.
Attention! The sequence of valve installation, counting from the front of the engine (from the side of the valve timing drive), is the same in each cylinder: the first (near the valve timing drive) is the intake valve, and the second is the exhaust valve.
7. Repeat the described actions for the valves of the remaining cylinders, in the injection sequence (1–3–4–2, counting from the valve timing drive side).
Adjustment
1. Adjusting the valve clearance involves replacing the adjusting plate located in the tappet recess. Replacing the adjusting plates does not require removing the camshaft if a special device is used to perform this operation.
Attention! When replacing the valve clearance adjustment plates, the engine pistons should not be exactly at TDC, but a few millimeters lower (about 1/4 of a crankshaft revolution). This will prevent the valve from hitting the bottom of the piston pressed when replacing the adjustment plate.
2. Turn the tappets so that after compression, special pliers for removing the adjusting plates can be easily inserted into the cutouts in the tappet bottoms (indicated by arrows).
3. Set the engine crankshaft to the appropriate position (see description above) and, using the pressure device (device 21.106), press the pusher down (opening the valve and compressing its spring at the same time) so that, using special pliers (21.107), the adjusting plate can be removed.
4. Measure the thickness of the removed plate and, taking into account the measured gap and the required nominal value, select from the kit a plate of such thickness that will provide the required valve clearance.
5. Insert the selected plate so that the surface with its designation is directed downwards (towards the pusher).
6. Remove the pressure device.
7. Repeat the described operations for the remaining valves.
8. Install the cylinder head cover with a new gasket.
9. Connect the elastic hose of the engine crankcase ventilation system to the cylinder head cover.