Examination
Warm up the engine to operating temperature (the coolant temperature is above +35°C, the cylinder head must be warm to the touch).
Disconnect the fuel supply hose from the carburetor, close the openings of the hose and the carburetor nozzle with plugs. Remove cylinder head cover.
Turning the crankshaft with a wrench on the toothed pulley mounting bolt, install in series each camshaft cam with the back of the pusher on the end of the pusher and measure the gap between the back of the cam and the shim on the valve lifter with a set of feelers.
Warning. It is not recommended to turn the camshaft directly by the pulley mounting bolt, so as not to damage the toothed belt.
Adjustment
The first adjustment of valve clearances after repair should be carried out on a cold engine. Adjust the valve clearances if deviations from the permissible values are detected during the check.
Adjustment of gaps in the valve drive mechanism. Checking the gap between the back of the cam and the shim at the end of the pusher
Clearances in the valve drive mechanism
The gap between the camshaft cams and shims on a warm engine should be 0.25±0.05 mm for intake valves and 0.45±0.05 mm for exhaust valves, on a cold engine, respectively 0.20±0.05 and 0.40±0.05 mm.
Record clearance values Zi for each valve.
Install the valve of one of the cylinders (#2 1, 3, 4 or 2) to the position of maximum clearance between the cam and the shim, thus loading the pushers of the opposite cylinder (№2 4, 2, 1, 3), adjust the clearance.
Using the VW 546 tool, push the pushers of the intake and exhaust valves into the cylinder head. Turn the tappet slot perpendicular to the camshaft axis and use a special puller 10 208 to remove the valve adjusting washer.
Measure the thickness T of the removed washer with a micrometer and calculate the thickness of the new washer using the formula:
Tn=T+Zi-Zn,
Where:
Tn is the thickness of the new washer;
T is the thickness of the removed washer;
Zi - measured clearance;
Zn - nominal clearance.
Pick up a washer of the required thickness and install it on the pusher with the mark towards the pusher.
Remove tool VW 546.
Adjust the clearances on the other valves in the same way.
Finally adjust the valve clearances on a warm engine if the initial adjustment was carried out on a cold engine.
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