NC, 3D and 1T motors
Check of serviceability of hydraulic pushers
Warning: After installing the hydraulic tappets, wait at least 30 minutes, then slowly crank the crankshaft two full revolutions before starting the engine, otherwise the pistons may hit the valve heads. It takes some time for the pushrod components to properly fit into place.
1. Hydraulic tappets adjust valve clearance automatically and do not require any maintenance.
2. If the hydraulic tappets are too noisy, check their operation in the following way.
3. Start the engine and let it warm up to normal operating temperature. Increase engine speed to 2500 rpm for approximately 2 minutes.
4. To determine which tappet is faulty, turn off the engine, then remove the camshaft cover (see chapter 8).
5. Rotate the crankshaft with a wrench to turn the camshaft so that the lug on the first cam of cylinder #1 points up.
6. Press down on the pusher with a wooden or plastic tool until you feel it touch the valve stem. Using a feeler gauge, measure the clearance between the cam base and the top of the valve lifter. If the gap exceeds 0.1 mm, the plunger is defective and must be replaced.
7. Removal and installation of the pusher are described in Section 1B as part of the cylinder head rebuild procedure.
CN and DE engines
Checking and adjusting valve clearances
8. Valve clearances are regulated by washers of various thicknesses installed in the pusher. Gaskets are manufactured in thicknesses from 3.00 to 4.25 mm in increments of 0.05 mm.
9. Adjust clearances after installing new camshaft or valves. The clearances must be re-checked after 1000 km, on a warm engine with a coolant temperature of 35°C.
10. Remove the valve cover.
11. Turn the crankshaft by setting the cams for one cylinder to the highest position. Check the clearance between the cam and the follower and record the measurements. Compare your readings with the data below: Engine Intake Exhaust CN, DE 0.20-0.30 mm 0.40-0.50 mm
12. Repeat for all four cylinders. The valves are numbered from the toothed belt. Inlet valves - No. 2-4-5-7-9, exhaust valves - No. 1-3-6-8-10.
13. If the clearance of any valve exceeds the value given in the Specifications, remove the appropriate washer. Set the piston of the cylinder to TDC on the compression stroke, press the pushrod so that you can remove the shim from the pushrod (see illustration). Each pusher has notches in the top frame that are made to facilitate the removal of the puck (see illustration).
14. Note the thickness of the shim (engraved on the back (see illustration), and calculate the thickness required to set the correct gap.
15. If the washers are not worn or damaged when removed, they can be reused.
16. Install valve cover with new gaskets (see illustration).
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