Disassembling a DOHC engine (Mazda Capella GD)

Disassembly of this engine is carried out in the same way as described for the standard engine. The difference, of course, is in the steering due to the installation of two camshafts. The following description therefore covers only the removal of the timing gear and the timing head. First of all, you need to remove the parts of the distribution mechanism, using the drawing 30:

• Hold the crankshaft from turning and loosen the belt pulley bolts. Remove the belt drive pulley (1).
• Unscrew the upper (2) and lower (3) timing belt protective covers and remove both seals.
• Remove the guide cap (4) from the end of the crankshaft.
• Loosen the bolt in the middle of the control belt tensioner (5), remove the spring and push the tensioner in as far as possible.
• Use a pencil to mark the direction of rotation of the belt on its outer side in case it is to be used again, and remove the belt from the drive pulleys. Keep belt away from oil, grease and other corrosive substances or liquids. In this case, you need to ensure that it does not bend or come into contact with oil, water or other harmful substances. It is best to hang the belt on a nail.
• If necessary, unscrew the drive roller (6) for the toothed belt.
• Loosen the bolts of both camshaft timing pulleys using a socket wrench. To do this, insert the rod into the groove of the belt pulley, as shown in the figure 31. so that it does not turn.

• Remove the belt drive pulley (8) from the camshaft.
• Unscrew the front cover from behind the belt drive pulley.
• Hold the flywheel again as described above and release the crankshaft drive wheel bolt. Carefully press the drive wheel (9) away from the crankshaft using two oppositely directed tyre levers or use a suitable puller for removal.
• Removal the cylinder head is carried out as follows. Figure 32 shows the assembly drawing of the cylinder head and can be used in the work:

(The article is copied from the resource: «www.MazBook.ru»)

• Gradually loosen the camshaft bearing cap fastening bolts (3) and remove both camshafts from the cylinder head.
• Remove the hydraulic tappets (5) and lay them out in the assembly sequence.
• Using the drawing 33. Loosen the cylinder head bolts in the order shown in several steps. If the cylinder head does not come out, you can insert a screwdriver between the protrusion on the head and the cylinder block and press on the head. Do not, under any circumstances, attempt to insert a screwdriver between the sealing surfaces to press on the head.

• Remove the cylinder head gasket.
• The remaining cylinder block now looks like an engine block with a camshaft and can be handled accordingly. In chapter 2.2.1 the remaining disassembly work is described.