Contents: Removal ⇓ Installation ⇓
Removal
1. Remove the cylinder head cover (see paragraph 4).
2. On early models prior to 1997, remove the ignition distributor (see chapter 5).
3. Remove the timing belt and camshaft sprockets (see paragraph 6).
4. Measure the axial play of the camshafts with a dial indicator (Fig. 7.4). If the play exceeds the permissible value (see Technical Data), replace the shaft and/or shaft thrust flange.
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5. In the opposite order to that shown in the figure 7 14, alternately loosen the camshaft support cap bolts 1/4 turn at a time until they can be removed by hand.
Be careful: when tightening the bolts, the camshaft must rise evenly upwards. If one end of the shaft stops lifting and the shaft is warped, re-tighten the camshaft cap bolts, turn the camshafts and begin to loosen them again. DO NOT attempt to lift the camshaft by levering or otherwise forcibly.
6. Completely unscrew all bolts and remove the support covers. Store them in a sequence that will allow for easy reinstallation in their original locations. In addition, the lids must be labeled (figure 7.6).
7. Lift the camshaft without distortion and remove it from the engine.
8. Engines produced before 1997 use hydraulic tappets, while later engines use tappets with adjusting shims. Regardless of the type of tappets, they can be removed using a magnet (Fig. 7.8, a). Store the tappets together with their gaskets so that all parts can be installed in their original places during assembly (figure 7.8,b). Please note: Hydraulic tappets should be stored upside down in clean engine oil.
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9. Thoroughly wipe the camshafts, remove the seals from them and proceed to inspect the shafts and tappets (see chapter 2B).
Installation
10. Lubricate the tappets with molybdenum grease and insert them back into their original positions. Install adjusting shims on the upper ends of the pushrods (on engines produced since 1998).
11. Lubricate the camshaft cams and journals with molybdenum grease.
12. Carefully lower the shaft onto the supports. Rotate the shaft so that the forces exerted by the valve springs are approximately equal along the length of the shaft. Install the support caps in the correct order and tighten the bolts that secure them by hand for now.
13. Before installing the front (thrust) cover, apply a thin bead of RTV sealant to the outer edge of its base, which mates with the cylinder head. Keep in mind that the cover must be installed immediately after applying the sealant, otherwise the sealant will dry immediately.
14. In the sequence shown in the figure 7.14, gradually tighten the camshaft cover bolts no more than 1/4 turn at a time until the required torque specified in Technical data.
15. Lubricate the new seal with engine oil and place it on the shaft by hand.
16. Using a piece of pipe or a socket head of a suitable diameter, press the cuff flush with the shaft cover torquing or to the depth of the previously installed cuff.
17. Install the remaining parts in the reverse order of removal.
18. Start the engine and check there. that it works fine.
Note: On some models, the valve lifters may make noise after assembly. If the tappets are found to be in good condition after the inspection described in chapter 2B, then the noise may be caused by a faulty oil pump. Due to leaks in the pump, air can get into the oil, although there are no oil leaks outside. Air entering the tappets displaces the oil from it and causes a rumble. If the noise does not go away after the engine warms up, the oil pump may need to be replaced.