1 - cylinder head; 2.7 - centering sleeve; 3.8 - screw plug (M8x1); 4 - cover (∅28); 5 - hairpin (M6x30); 6 - hairpin (M6x60); 9 - hairpin (M6x28); 10 - bolt (M8x28); 11 - harness holder; 12 - spacer; 13 - sealant; 14.30 - cover; 15 - self-blocking nut; 16 - nut (M7); 17 - hairpin (М7x95); 18, 20 - center, sleeve (∅9,5); 19 - support bar; 21 - bolt T (M6x50); 22 - bolt T (M6x70); 23 - bolt 7 (M6x100); 24 - screw plug with sealing ring (М12x1.5x26); 25 - bolt; 26.35 - sealing ring; 27 - hairpin (М7x39); 28 - hairpin (M7/6x29.5); 29 - screw plug (M18x1.5); 31 - guide sleeve; 32 - head bolt (M10x110); 33 - gasket washer; 34 - cover (∅22); 36 - screw plug (M10x1.0); 37 - cover (∅18); 38 - hairpin (M7x55); 39 - sensor; 40 - saddle issue. valve; 41 - saddle vp. valve; 42 - hairpin (M6x25); 43 - sealing gasket; 44 - check valve
The signs of damage are:
- power loss;
- drop in coolant level;
- drop in oil level;
- the presence of coolant in the oil;
- the presence of oil in the coolant;
- foaming coolant;
- lack of compression in adjacent cylinders.
Replacing the cylinder head gasket consists of three steps - removing the cylinder head, replacing the gasket, and installing the cylinder head.
Removal of a head of the block of cylinders of the engine is necessary for carrying out in a following order. Prepare fixture «00.9.120».
Remove both exhaust manifolds and air cleaner housing together with air mass meter.
Remove the cylinder head cover and remove all spark plugs. Remove the intake manifold, drain the coolant by unscrewing the plug on the engine block. Disconnect the cooling system pipes and remove the thermostat housing.
unscrew hollow bolt (29, see fig. 3.63) and disconnect the pressure oil line of the D-VANOS timing unit.
Pic. 3.63. Cylinder head cover: 1, 19 - plug; 2 - nut; 3 - protective cover; 4 - overlay; 5, 28, 31, 33, 39 - sealing ring; 6, 23 - locating pin; 7 - rubber-metal hinge; 8, 9 - cap nut; 10 - gasket washer; 11 - sealant; 12, 13, 14 - profile gasket; 15, 37 - sealing ring (17x3); 16, 35 - camshaft sensor; 17, 34 - bolt (M6x16); 18 - precision bolt; 20 - plug with a sealing ring; 21 - flange hook; 22 - mount; 24 - nut M6; 25 - jumper «masses»; 26 - bolt (M6x10); 27 - nut M8; 29, 32 - hollow bolt; 30 - oil pipeline; 36 - EMC; 37 - ring (17x3); 38 - piston; 39 - spring; 40 - cylinder head; 41 - metal seal; 42 - executive unit; 43 - oil filler cap; 44 - head cover
Remove the D-VANOS adjustment unit. Remove camshafts together with support strips (19, see fig. 3.4) bearings.
Unscrew the vertical bolts securing the timing cover to the cylinder head (arrows, fig. 3.67).
Loosen the top guide bolts (9,10,15, see fig. 3.13) chains.
1— crankshaft; 2,8,14,15 - asterisk; 3—tensioner bar; 4 - piston; 5—spring; 6 - sealing ring; 7—cover bolt; 9.16 - chain; 10,12—bolt bars; 13 - key; 17—exhaust camshaft; 18 - intake camshaft; 19 - hydraulic pusher; 20 - valve cotters; 21 - top plate; 22—spring; 23 - bottom plate; 24 - oil scraper cap; 25 - inlet valve; 26 - exhaust valve
Unscrew the cylinder head bolts from the edges to the middle in the sequence 14-1 (pic. 3.68) and remove the cylinder head.
Replacing the seal (43, see fig. 3.4) must be done in the following order. Remove the old sealing gasket, it is not subject to further use.
Clear sealing (docking) surfaces on the timing cover, engine head and cylinder block using only a hardwood scraper for this purpose (oak, hornbeam, beech). When doing this, make sure that seal residues do not burst into the air, oil and coolant channels.
To remove traces of liquid (oils), blow out the threaded holes in the cylinder block and cylinder head with compressed air. The presence of liquid leads to cracks and incorrect determination of the tightening torque.
Check centering sleeves (arrows, fig. 3.69) for damage and correct installation.
Apply sealing compound such as Drei Bond 1209 to the joints with the timing case cover. Replace the cylinder head seal by installing it on the centering sleeves.
Attention! For a cylinder head with a machined sealing surface, install a thicker (by 0.3 mm) sealing gasket.
Install the cylinder head in the following order. Lightly lubricate the seating surfaces of the washers and the threads of the new engine cylinder head bolts with engine oil.
Insert new cylinder head bolts and hand-tighten in a criss-cross pattern starting from the middle and moving towards the edges of the engine. Using a manometric wrench and tool «00.9.120».
Attachment 00.9.120
Tighten new cylinder head bolts in sequence 1-14 (see fig. 3.68) in three consecutive steps:
- first, tighten to 40 Nm (4.0 kgf·m);
- second, tighten by an angle of 90°;
- third, turn another 90°.
- Install the top chain guide. Insert bolts and tighten the threaded connections of the timing case cover to the cylinder head. Install camshafts.
- Install the Doppel-VANOS adjustment unit, hollow bolt (M 14x1.5) tighten oil lines to 32 Nm (3.2 kgf·m).at the same time, replace its sealing rings.
- Assemble the engine, while replacing the bolt gasket (M14x1.5) drain hole of the engine block, and tighten it with a torque of 25 Nm (2.5 kgf·m). Fill the cooling system, bleed it and check for leaks.