Withdrawal
Remove the toothed belt.
Remove the cylinder head cover.
Remove the camshaft pulley.
Exhaust camshaft
Unscrew a flange and a cover of the bearing of the distributor of ignition.
Pic. 3.2–39. Valve mechanism: 1 - nuts, 15 Nm; 2 – a cover of the bearing of a camshaft; 3 - chain; 4 - nut, 15 Nm; 5 – a forward cover of the bearing of a camshaft; 6 - hydraulic valve lifters; 7 - compensating element; 8 - valve cotters; 9 - the upper plate of the valve spring; 10 - valve springs; 11 - oil seals; 12 - intake camshaft; 13 - nuts, 15 Nm; 14 - exhaust camshaft; 15 - hydraulic valve lifters; 16 - the lower plate of the valve spring; 17 - bolt, 10 Nm; 18 - flange; 19 – a head of the block of cylinders; 20 - valves
Pic. 3.2–40. Location and numbering of camshaft bearing caps
Unscrew and remove the camshaft bearing caps from the chain side and caps 2 and 3 (pic. 3.2–40).
Gradually, evenly crosswise unscrew the covers 1 and 4 of the camshaft bearings.
Inlet camshaft
Turn out and remove covers 6 and 7 bearings of a camshaft.
Gradually, evenly crosswise unscrew the covers 5 and 8 of the camshaft bearings.
Remove camshafts.
Installation
Pic. 3.2–41. Installation of intake camshafts
Lubricate the camshafts with a thin layer of engine oil and install them in the cylinder head so that the marks on the sprocket shafts are directed towards each other (pic. 3.2–41).
When installing, note that the bearing caps are numbered from the front of the intake camshaft.
Before installing the outer camshaft covers, apply a thin layer of sealant D 454 300 02 to the mating surfaces of the covers.
Inlet camshaft
Install covers 5 and 8 (see fig. 3.2–40) camshaft bearings and secure them with nuts, tightening them gradually crosswise.
Exhaust camshaft
Install covers 1 and 4 (see fig. 3.2–40) camshaft bearings and secure them with nuts, tightening them gradually crosswise.
Install and secure the remaining covers.
Further installation is carried out in the reverse order of removal.
Checking hydraulic valve lifters
The correct setting of valve clearances largely determines the operation of the engine. If the valve clearances are too large, the engine will be noisier and the efficiency will be reduced because the valves open too late and close too early. If the valve clearances are too small, the valves may not close fully on a hot engine, which can result in serious engine damage.
Hydraulic tappets are installed on the engines, which automatically compensate for the gap between the camshaft cam and the corresponding valve stem under the action of pressure in the lubrication system. Therefore, during operation, regular checking and adjustment of valve clearances is not required. However, you must use engine oil of good quality and recommended viscosity and replace it at the required intervals. When starting a cold engine, there is a slight delay in the equalization of engine oil pressure in all parts of the engine, especially in the hydraulic tappets. The valves may knock for approximately 10 seconds, after which they continue to operate silently.
If the engine has not been started for several days, the valves may knock for a longer time as almost all of the oil drains from the top of the engine and bearing surfaces. At this time, care must be taken not to damage the engine: avoid sudden changes in engine operation until all pushrods are filled with engine oil. When the engine warms up, the fast idle speed (from 2000 to 2500 min–1) should not rise for 2 minutes or until valve banging stops. If the tappet noise does not stop, stop the engine and do the following while keeping the engine temperature at least 80°C.
Remove the cylinder head cover.
Turning the crankshaft, install the cam over the pusher to be checked straight up.
Pic. 3.2–42. Checking the free travel of the pusher
Press the pusher with a wooden or plastic wedge (pic. 3.2–42). If the pusher play is greater than 0.2 mm, the pushers must be replaced.
Install the cylinder head cover.
Wait approximately 30 minutes before starting the engine. This is necessary in order to stabilize the operation of the hydraulic tappets, otherwise the pistons will hit the valves.
Valve seat processing
Valve seats with signs of wear or burning must be processed with the obligatory preservation of angles and chamfers.
Pic. 3.2–43. The minimum allowable distance from the end face of the valves to the top surface of the cylinder head
If the valve seat needs to be machined, determine the maximum amount of metal that can be removed. Removing too much metal disrupts the operation of the hydraulic tappets. Insert the valve into the guide sleeve and press it against the valve seat. Measure the distance from the end of the valve stem to the top surface of the cylinder head (pic. 3.2–43).
If the valve seat is excessively worn, machining is unacceptable, so the cylinder head must be replaced.
After machining the valve seats, they must be lapped.
Replacement of sealing rings of a camshaft
Remove the toothed belt.
Remove the camshaft pulleys on the left and right cylinder heads.
Pic. 3.2–44. Arrangement of bolts of fastening of a casing of a gear belt
Remove the toothed belt covers on the left and right cylinder heads (pic. 3.2–44).
Warning
Pic. 3.2–46. The location of the sealing rings in the front of the cylinder head
On the left side there are two O-rings and a camshaft O-ring, on the right side there is one O-ring and a camshaft O-ring (see fig. 3.2–46)
Pic. 3.2–45. Using Special Tool 2056 to Remove the Camshaft O-Ring
Using special tool 2056, remove the camshaft O-ring (pic. 3.2–45).
Warning: If at least one o-ring is damaged, the o-rings on both sides must be replaced.
Clean the O-ring installation site.
Lubricate the lip and outer surface of the new O-ring with engine oil before installing it.
Using a drift, install the O-ring in place.
Install the camshaft pulleys.
Install the toothed belt.
Checking and adjusting poly V-belt alignment
Poly V-belt alignment is checked between the air conditioning compressor and the power steering pump.
Pic. 3.2–10. Installing tool 3204 to loosen the poly V-belt tension
Loosen the poly-V-belt tension by pressing the lower branch of the poly-V-belt and, using tool 3204, lock the belt tensioner in this position (see fig. 3.2–10). Remove poly V-belt.
Pic. 3.2–47. Using tool 3201 to check the alignment of the grooves on the pulleys of the air conditioning compressor and power steering pump
Using tool 3201, check the alignment of the belt grooves on the A/C compressor and power steering pump pulleys (pic. 3.2–47).
Pic. 3.2–48. Using shims to adjust the position of the power steering pump pulley
If the grooves on the pulleys do not match, unscrew the power steering pump pulley. Adjust the position of the pulley using shims 0.5 thick; 1.0 and 1.5 mm, which are supplied as spare parts (pic. 3.2–48).
Pic. 3.2–49. Flywheel: 1 - ring gear (before installation on the flywheel, it must be heated to a temperature of 200°C); 2 - pin for the TDC sensor; 3 - bushing of a needle bearing; 4 - bolt
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