BMW 5 series E39

Since 1996-2001 of release

Repair and car operation

Procedures of repair of the engine

The general information

Engine M52 (520i, 523i, 528i)

Engine M51 (525tds)

On cars BMW of 5th series engines of three types are established: a 6-cylinder petrol, 6-cylinder turbodiesel and engine V8. Engines V8 (volume 3.5 and 4.0) it is considered only in section "Maintenance service".

The power unit is established along the car and taken out only upward by the crane.

The 6-cylinder petrol engine has designation М52. Its head and the block of cylinders are cast from an aluminium alloy. Unlike traditionally applied pig-iron the aluminium alloy has higher heat conductivity and smaller weight. It promotes the best cooling and lower expense of fuel. The head of cylinders 4-klapannaja, has an adjustable camshaft of inlet valves (firm BMW designation - VANOS).

On model 525tds 6-cylinder turbodiesel М51 in volume of 2.5 l is established. The block of cylinders is cast from pig-iron, a head of cylinders from an easy alloy.

At the raised deterioration and presence задиров walls of their cylinders it is possible хонинговать. After that it is necessary to apply repair pistons.

The head of cylinders at all engines has a so-called cross-section purge. It means that the fuel mix arrives in working cylinders on the one hand, and the fulfilled gases leave with another. It promotes faster gas exchange. In a head of cylinders camshafts are located. The diesel engine has only one camshaft. 4-klapannye petrol engines have two camshafts. One actuates inlet valves, another final. The drive of camshafts is carried out through a roller chain. Valves are set in motion through hydropushers. Necessity of adjustment of backlashes for valves in the course of maintenance service is absent.

6-cylinder petrol engines have an adjustable drive газораспределения. Thus the camshaft of inlet valves depending on number of turns of the engine by means of an adjusting element is turned rather приводной asterisks in such a manner that the optimum moment of opening of valves is provided. Adjustment is carried out by the block of management opening and closing the oil valve of pressure.

Oil giving in greasing system is carried out by the oil pump which at the 6-cylinder petrol engine settles down in front in the pallet картера and set in motion from a cranked shaft. At the diesel engine the oil pump is in a cover картера a distribution drive on the end of a cranked shaft and is set in motion from a tooth gearing. Oil is sucked in from the pallet картера and through apertures and pipelines moves to bearings of cranked and distributive shaft, and also to working surfaces of cylinders.

The pump of a cooling liquid is located in a forward part of the block of cylinders. The pump shaft at achievement of the corresponding temperature actuates the cooling fan through вязкостную муфту. The pump drive is carried out through клиновой a belt which simultaneously actuate the generator. It is necessary to mean that the cooling system is all-the-year-round filled by an antifreeze mix, a protection frame from corrosion and water with the low maintenance to exhaust.

Preparation of an air-petrol mix is carried out by system of injection and electronic ignition thanks to what stable value of issue of the fulfilled gases is provided. The system of ignition with coils of ignition has no mobile elements that excludes deterioration of its elements. At the diesel engine fuel distribution on cylinders is carried out by system DDE (digital diesel electronics).

Petrol engines are calculated for work on gasoline АИ-95, however thanks to presence of detonation regulation can be applied and other grades of fuel. If gasoline АИ-98 under normal conditions operation the expense of fuel decreases is applied and capacity of the engine raises. At application of gasoline АИ-91 capacity of the engine decreases and the fuel expense raises.