Gasoline car engines BMW 5 Series E12

General information about the engine
On BMW 5-series models "518", "520", "520i" a four-cylinder engine was installed on the "520" models from the 1978 model year, "520i", "525", "525i", "528",...

Cylinder Head Specifications
The head is cast from an aluminum alloy and contains combustion chambers with transverse gas movement (models "518", "520", "520i") or three-spherical...

Cylinder Block Specifications
The cylinder block is cast from a special grey cast iron and is one piece with the cylinders. Grinding the plane of the cylinder block joint with the head is...

Valve timing specifications
The engine uses a valve timing mechanism with an overhead camshaft, the drive of which is carried out by a double-row roller chain or a toothed belt (BMW "520"...

Removal the cylinder head
Note: This and subsequent sections provide recommendations for repair and maintenance of BMW vehicles "518", "520" and "520" with a 4-cylinder engine, "525"...

Disassembling the cylinder head
Remove the ignition distributor and its mounting bracket. Install the cylinder head on the support 6025/1 (models "518", "520") or on stand 7003/1 (models...

Checking the technical condition of the cylinder head
Before checking, wash all parts with trichloroethylene, clean the mating surface of the cylinder head with a scraper, clean the combustion chambers and exhaust...

Cylinder head repair
Replacing valve guide bushings If one of the valve guide bushings is heavily worn (see wear limits in subsection " Detailed technical specifications ") replace...

Cylinder head assembly
Clean and check the condition of the parts thoroughly. The cylinder head is assembled in the reverse order of disassembly, taking into account the following:...

Intake manifold
Intake manifold of the BMW "520" engine: 6 - air intake adjustment screw; 7 — carburetor starter temperature sensor; 9 — vacuum selection valve. Intake...

Installing the cylinder head
After cleaning the mating surface of the cylinder block, check the protrusion of the mounting pins above its plane, which should not exceed 5 mm. Make sure...

Adjusting clearances in the valve drive mechanism
The clearances in the valve drive mechanism are adjusted by slightly opening the valves by turning the adjusting eccentric of the rocker arm, after first...

Engine suspension cushion replacement
This operation does not require disconnecting any pipelines or electrical wires. Loosen the nut securing the engine to the cushion. Support the engine and...

Removal and installation the engine
Removal Disconnect the wires from the battery terminals, drain the liquid from the cooling system by unscrewing the drain plugs on the radiator and cylinder...

Removal and installation of the power unit
Removal and installation of the power unit are performed similarly to removal and installation of the engine. However, to move the engine forward by a greater...

Disassembling the engine
Mount the washed and cleaned engine on the 6000 rotary disassembly stand using the 6001 mounting plate (models "518", "520") or 7001 plates (models "525",...

Disassembly and assembly of the connecting rod and piston group
The piston pins rotate freely in the upper head of the connecting rod and the piston bosses. The pin is held in the piston bosses from longitudinal movement by...

Crank mechanism parts
Crank mechanism parts: A - "5201" engine with Kugetfischer fuel injection system; A1 - engines of models "518", "520"; A2 - engines of models "525", "528". 1 -...

Installing the crankshaft
Make sure that the crankshaft main bearing journals and shells are of the same size group. Color codes (red or blue) on the main bearing shells must be...

Replacing the centering bearing of the primary shaft of the gearbox
Press out the bearing with the protective washer, felt ring and protective cover from the crankshaft flange socket using the Kukko puller. Thoroughly clean and...

Replacing the flywheel toothed rim
Check the condition of the flywheel toothed rim and, if the teeth are significantly worn, replace the toothed rim. Drill a hole about 8mm deep into the rim...

Grinding the flywheel
The plane of contact of the driven disk on the flywheel must be smooth, without scratches and burrs. Scratches and burrs are removed by grinding. After...

Checking the clearance between the bearing shells and the main journals of the crankshaft
Install the ungreased lower main bearing shells into the cylinder block seats (axial fixation of the crankshaft is provided by liners with cheeks of the middle...

Checking the axial clearance of the crankshaft
Install the crankshaft rear oil seal retainer with a new gasket. Install the flywheel on the crankshaft. Lock the flywheel with lock 7007, install new mounting...

Checking the clearance between the bearings and the connecting rod journals of the crankshaft
Insert the pistons into the cylinders (without piston rings) with connecting rods in accordance with the cylinder number marks on the piston bottom (the count...

Installing the camshaft drive
Install the chain tensioner guide and shoe (see the figure "Camshaft Drive Diagram") and make sure that the shoe rotates freely around its axis. Place the...

Exhaust system Details
Exhaust system parts

Timing mechanism parts
Details of the valve timing mechanism of a 4-cylinder engine: 1 - camshaft sprocket; 2 - rocker arm axes for intake and exhaust valves; 7 — rocker arm; 9 —...

Replacing the camshaft drive belt of the 6-cylinder BMW «520» and «520i» engine
Drain the cooling system. Remove the fan guide shroud. Remove the fan. Disconnect the coolant drain hoses. Remove the bracket located behind the radiator inlet...

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