Pic. 43. The cover of the camshaft drive mechanism and its attachments: 1 - alternator mounting bolt, 45 Nm; 2 - alternator; 3 - bolt, 25 Nm; 4 - washer; 5 — a bolt of fastening of an arm of the generator, 45 Н·м; 6 - washer; 7 - generator bracket; 8 - fuel filter; 9 - fuel filter mounting bolt, 10 Nm; 10 — a bolt of fastening of a cover of a head of the block of cylinders, 10 Nm; 11 — a cover of a head of the block of cylinders; 12 - bolt, 25 Nm; 13 - bolt, 10 Nm; 14 - bolt, 10 Nm; 15 - cover of the camshaft drive mechanism; 16 — a bolt of fastening of a cover of the mechanism of a drive of a camshaft, 25 Nm; 17 - laying of the oil pan; 18 - oil pan; 19 — a bolt of fastening of the oil pan, 25 Nm; 20 - vibration damper hub; 21 - elastic washer; 22 - bolt, 320 Nm; 23 - vibration damper; 24 - drive belt pulley; 25 - washer; 26 — a bolt of fastening of the vacuum pump, 10 Nm; 27 - vacuum pump; 28 - vacuum pump gasket; 29 - bolt, 10 Nm; 30 - bolt, 10 Nm
The camshaft drive cover covers the engine crankcase from the front. It sits on two cylindrical dowel pins and is secured with 2 pan head bolts at the top, 5 bolts to the oil pan and 14 bolts to the cylinder block. A sealant is used to seal the connection between the camshaft drive mechanism cover and the engine crankcase. The following parts and components of the engine are attached to the cover of the mechanism (pic. 43):
- brake system vacuum pump;
- water pump;
- fuel filter;
- power steering pump;
- the support pin of the alternator drive belt tensioner;
- front crankshaft cuff;
- TDC indicator pin;
- oil dipstick guide tube.
Pic. 44. Cover of the camshaft drive mechanism with the indication of individual parts (the details of the lid are shown below): 1 - support pin of the generator drive belt tensioner; 2 - guide tube of the oil dipstick; 3 - pin-indicator of the TDC position; 4 - hole with a flange for a vacuum pump; 5 - TDC sensor mounting pin on four-cylinder engines; 6 - front cuff of the crankshaft; 7 — a bolt of fastening of a cover of the mechanism of a drive of a camshaft to the block of cylinders; 8 - pin-indicator of the TDC position; 9 - mounting sleeve for mounting the TDC sensor; 10 - front cuff of the crankshaft; 11 — a bolt of fastening of a cover of the mechanism of a drive of a camshaft to the block of cylinders; 12 - elastic spring washer; 13 - the place of installation of the front cuff of the crankshaft; 14 - cover of the camshaft drive mechanism; 15 — the landing plug of the pump of the hydraulic booster of a steering
The camshaft drive mechanism cover can be removed without removing the engine from the vehicle. The sequence of work for dismantling the cover is described below. The dismantling of individual components is described in the respective chapters. On the top of Fig. 44 shows all the parts that must be removed when removing the cover.
Removing the cover of the camshaft drive mechanism must be carried out as follows:
- remove the dirt trap at the front of the car and drain the engine oil;
- disconnect «mass» battery terminal;
- remove all parts from the front of the car to provide good access to the engine;
- loosen the drive belt tensioner on the front end of the engine. The corresponding chapter provides a detailed description of the implementation of this work;
- remove the vacuum pump;
- unscrew the three bolts securing the power steering pump pulley and remove the pulley;
- remove the pump and, taking it aside, leave it hanging on the hoses;
- remove the drive belt tensioner. First of all, unscrew the bolt at the top of the damper. Remove the cover from the tension lever, unscrew the bolt and remove the lock washer. Remove the tension lever together with the damper and the tension spring from the support pin on the cover of the camshaft drive mechanism;
- unscrew the front of the two fuel filter mounting bolts;
- unscrew the fastening elements of the belt pulley of the crankshaft vibration damper;
- shift into gear to block the crankshaft from turning. Loosen the crankshaft pulley hub fasteners and remove the hub from the shaft flange. Often the hub is removed easily, if necessary, use a puller;
Pic. 45. Fastening the position sensor of the piston of the first cylinder at TDC on the cover of the camshaft drive mechanism
- remove the piston position sensor of the first cylinder at TDC in the stroke of the stroke. To do this, unscrew the nut 1 shown in Fig. 45, pull the sensor cable out of the mounting socket 3 and lay it aside. On five-cylinder engines, this sensor has been moved to the right side of the camshaft drive mechanism cover for space reasons;
- remove the alternator together with the mounting bracket;
- on vehicles with an automatic transmission, the oil lines must be disconnected from the transmission oil cooler. Close open openings properly;
- unscrew the front fixing bolts of the oil pan located in the area of the cover of the camshaft drive mechanism, and then all the other fixing bolts of the pan;
Pic. 46. Cylinder head cover of a five-cylinder diesel engine (602): 1 - hose of the crankcase ventilation system; 2 - round gasket on the cylinder head; 3 - oil filler cap; 4 - rubber gasket for the oil filler cap; 5 — a cover of a head of the block of cylinders; 6 — a bolt of fastening of a cover of a head of the block of cylinders; 7 — a lining of a cover of a head of the block of cylinders
- remove the cylinder head cover. It is attached with 8 bolts. First, remove the crankcase ventilation hose that is attached to the middle part of the cover. On vehicles with an automatic transmission, it is also necessary to disconnect the rods passing over the cylinder head cover. On fig. 46 shows a cylinder head cover for a 2.9L diesel engine;
Pic. 31. The sequence of tightening the cylinder head bolts on a 2.3 liter engine
Pic. 32. The sequence of tightening the bolts of the cylinder head on a 2.9 liter engine
- unscrew the two M8 socket head cap screws «by 6 mm», using an extension of at least 440 mm, in the chain case (see bolts a in fig. 31 and 32);
- unscrew the fasteners and remove the retaining clamp of the oil dipstick guide tube from the cover of the camshaft drive mechanism;
- unscrew the fixing bolts of the fuel pump and the square nuts on the pump flange;
- unscrew the remaining fixing bolts of the cover of the camshaft drive mechanism and remove the cover. Since the fixing bolts have different lengths, they must be marked before unscrewing. When doing this, be very careful not to damage the cylinder head gasket. Otherwise, it will also have to be changed.
The camshaft drive mechanism cover must be installed in the following order:
- thoroughly clean the adjacent surfaces of the cover of the camshaft drive mechanism and the cylinder block from the remnants of the old sealant. The surface of the camshaft drive mechanism cover should also be checked for damage that could cause oil leaks;
- Apply sealant to the sealing surfaces of the camshaft drive mechanism cover. Mercedes-Benz specialist workshops use Curil T sealant, which can be purchased if you specify the part number: 001 989 47 20 (you can use similar grades of sealant, for example Hylomar);
- carefully attach the cover of the camshaft drive mechanism to the cylinder block, being careful not to damage the cylinder head gasket;
- alternately install in their places and tighten the fixing bolts of the cover of the camshaft drive mechanism;
- if it is necessary to replace the crankshaft seal, then it must be placed on the crankshaft flange and carefully inserted into the cover of the camshaft drive mechanism;
- reinstall the fuel filter.
All other work must be carried out in the reverse order of removal. In addition, you must do the following:
- tension the drive belt (see the relevant subsection.);
- fill the engine with the required amount of engine oil of the required brand;
- fill the cooling system;
- start the engine and check the docking points for oil leaks.