E39 series BMW 5

since 1996-2001 of release

Repair and car operation

+ Introduction
+ Maintenance instruction
+ Current leaving and service
+ Engine
- Systems of cooling, heating
   - Cooling system
      Check of system of cooling
      Removal, installation and thermostat check
      Removal and installation of the fan and fan coupling
      Removal and installation of a broad tank
      Removal and radiator installation
      Removal and installation of the pump of cooling liquid
   + Heater
   + air Conditioner
+ Power supply system and release
+ engine Electric equipment
+ Manual transmission
+ Automatic transmission
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment
+ electric equipment Schemes
+ System of onboard diagnostics

Removal, installation and thermostat check

The thermostat at increase of temperature of the engine connects a big contour of cooling. If the thermostat owing to damage remains closed, the engine overheats. A sign of it is the index of temperature being in a red range. Thus cooling liquid remains cold. The faulty thermostat after cooling of liquid can remain open. A sign of it is the impossibility of achievement by the engine of working temperature or slower growth of temperature of cooling liquid, than still, and in the winter - falling of capacity of a heater.

If the engine heats up after small run of the car, radiator pollution owing to lime deposits can be the reason also.


Model 525tds

1 — the thermostat case
2 — a ventilation bolt
3 — the thermostat

4 — a sealing ring
5 — a bolt

Models 520i, 523i, 528i

1 — the thermostat case
2 — the thermostat
3 — a sealing ring

4 — consolidation
5 — bolt М6
6 — bolt М8


1. Remove the fan, address to the Section Removal and installation of the fan and the fan coupling.
2. Merge cooling liquid, address to the Section Replacement of liquid of system of cooling. Check of frost resistance of a cooler. Visual check of system of cooling.
3. Disconnect hoses from the thermostat case (from the forward party of the block of cylinders). For this purpose open collars.

4. Models 520i, 523i, 528i: Remove from the engine elevating eyes. Disconnect cable mine at clips and remove. Address to an accompanying illustration.

5. Unscrew a thermostat cover.

Bolts of fastening have various length, it is recommended to write down their lengths.

6. Pay attention to position of the thermostat and take out it.


1. Heat up the thermostat in capacity with water. Thus the thermostat should not concern capacity walls. The temperature is measured by the corresponding thermometer. Address to an accompanying illustration.

2. At temperature near +88°С the zaslonka of the thermostat starts to open. The beginning of opening is visible on the thermostat.
3. Check, whether the thermostat extends and whether is closed, and also whether the opening beginning coincides with the established value specified on the thermostat. If necessary replace the thermostat.


1. Clear sealing surfaces on the case and a cover.

2. Models 520i, 523i, 528i: Insert the thermostat into a head of cylinders so that the arrow showed up. Address to an accompanying illustration.

3. 525tds: Insert the thermostat so that the ventilating valve showed upward. The arrow is in a cover groove. Address to an accompanying illustration.

4. Slightly grease a sealing ring of the thermostat with glycerin and establish it, address to an illustration in the subsection "Removal".
5. 520i, 523i, 528i: Paper laying it is necessary to establish the new surely.
6. Establish the case of the thermostat and evenly wrap bolts of fastening the moment specified in Specifications.

Do not tighten bolts too strongly. Do not forget to establish load-lifting eyes at the 6-cylinder engine.

Bolts of fastening of an eye (М8) tighten the moment of 20 Nanometers.

7. Fix cable mine clips.
8. Establish the fan and a fan cover.
9. Fill system with liquid and remove air, address to the Section Replacement of liquid of system of cooling. Check of frost resistance of a cooler. Visual check of system of cooling.
10. Start and warm up the engine so that vyazkostny coupling connected the fan. Check, whether the radiator in the lower part got warm and check tightness of the case of the thermostat. In the presence of a leakage tighten fastening bolts.