1. Remove spark plugs if not already done.
2. Turn out a bolt of fastening of a gear wheel of a gear wheel on a camshaft. Remove the camshaft drive gear and use side cutters to remove the gear key. To prevent the toothed belt gear from turning, insert a drill or a suitable punch into the hole of the gear and fix it on the cylinder head (see illustration 4.9).
3. Remove the oil line from the middle of the cylinder head.
4. Loosen all 10 nuts securing the camshaft bearing caps, working from the ends to the center.
5. Mark the mounting position of the bearing caps and then remove them one by one.
6. Remove the valve lifters from the holes in order. Mark the mounting position of the tappets accordingly (see illustration).
6.6 Mark the mounting position of the pushers.
Remove the pushrod shims and fold them together with the pushrods.
In order to remove the valves from the cylinder head, you need a special tool that allows you to compress the valve springs (see illustration 6.0).
6.0 Removing valves
1 - special tool for removing valves
2 - stamp for compressing the valve spring
The shape of the special tool may differ from that shown in the illustration.
In the absence of a special tool, the valves can be removed as follows.
7. Insert a block of wood into the combustion chamber so that it rests against the valve that will be removed.
8. Attach a piece of pipe of the same diameter as the spring cup to the top side of the valve spring cup and hit the pipe piece with a hammer. This will compress the valve spring and release both valve cotters. This method of removing the valves is complicated by the inclined arrangement of the valves.
9. Remove the valve parts and remove the valve from the opposite side of the cylinder head. Immediately mark the mounting position of the valves accordingly, and put the valves and their parts together. Each valve guide has a flinger cap. Remove the caps using appropriate pliers or a screwdriver. Oil seals must be replaced with new ones (see illustration).
6.9 Remove valve stem seals
XU10 engine (with two camshafts and 16 valves)
10. Insert stop bolts «A» into the holes of the gears of the toothed belt and unscrew the bolts of the gears. After that, remove the stop bolts and remove both bushings from the camshafts (see illustration).
6.10 Dismantling the XU10 engine (with two camshafts and 16 valves).
1 and 2 - bolts of fastening of plugs of gear wheels of a toothed belt
a - thrust bolts
3 and 4 - toothed belt gear bushings
5 - bolts of fastening of a protective casing of a gear belt
6 - toothed belt guard
7 - oil lines
11. Turn out bolts of fastening of a protective casing of a gear belt.
12. Remove the toothed belt guard
13. Remove oil lines.
14. Remove the thermostat housing on the opposite side of the cylinder head.
15. Turn out for several passes 12 bolts of fastening of cases of bearings of camshafts and remove cases.
To remove the camshafts and cylinder heads, push on the camshaft from the flywheel side of the engine. This will release the opposite end of the camshaft from the centering bearing.
16 Remove the oil seals from the camshafts (see illustration).
6.16 The position of the camshafts after removing the bearing housings.
1 - camshafts
2 - camshaft seals
17. Remove the valve lifters from the holes in order. Mark the mounting position of the tappets accordingly (see illustration 6.6). Remove the pushrod shims and fold them together with the pushrods.
18. Remove valves and oil seals. See above for the procedure.