BMW 3 Series E30

since 1983-1994 release

Repair and operation of the car

+ 1. Maintenance instruction
+ 2. Maintenance
- 3. Engine
   + 3.1.2. Specifications
   - 3.2. Dismantle and capital repairs of the engine
      3.2.2. Specifications
      3.2.3. Capital repairs – the general instructions
      3.2.4. Check of a compression in engine cylinders
      3.2.5. Capital repairs – general comments
      3.2.6. Diagnostics of the engine by means of the vacuum gage
      3.2.7. Capital repairs – alternatives
      3.2.8. Dismantle of the power unit
      3.2.9. Removal and installation of the engine
      3.2.10. Order of dismantling of the engine
      3.2.11. Dismantling of a head of the block of cylinders
      3.2.12. Cleaning and check of a head of cylinders and details of the valvate mechanism
      3.2.13. Repair of valves
      3.2.14. Assembly of a head of the block of cylinders
      3.2.15. Removal of pistons and rods
      3.2.16. Dismantle of the crankshaft
      3.2.17. Intermediate shaft (only M20 engine)
      3.2.18. Cleaning of the block of cylinders
      3.2.19. Check of a condition of the block of cylinders
      3.2.20. Honningovaniye of cylinders
      3.2.21. Check of a condition of pistons and rods
      3.2.22. Check of a condition of the crankshaft
      3.2.23. Check of radical and conrod bearings
      3.2.24. Engine assembly order
      3.2.25. Installation of piston rings
      3.2.26. Installation of an intermediate shaft
      3.2.27. Installation of the crankshaft and check of gaps in radical bearings
      3.2.28. Installation of a back epiploon
      3.2.29. Installation of rods and pistons, check of gaps in conrod bearings
      3.2.30. Launch of the engine after repair and a running in
   + 3.3. Engine electric equipment
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. Exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. Running gear
+ 12. Body
+ 13. Electric equipment
+ 14. Useful tips


3.2.13. Repair of valves


Places of wear of the valve

1. End face

2. A pro-point under crackers

3. A core (a part with the smallest wear)

4. A core (a part with the greatest wear)

5. Facet

6. Corbel

1. Check a condition of the valve (see subsection 3.2.12). Replace strongly worn-out valves.
2. If as a result of this check it becomes clear that a condition of the valve satisfactory, then measure diameter of the valve in several places. Noticeable distinction of diameters indicates wear of a core of the valve. At detection of noticeable distinction of diameters at least in two places replace the valve.
3. If a condition of valves satisfactory, then them it is necessary to grind in to saddles. If on saddles there are only insignificant damages, or the saddle was exposed to regrinding, then grinding in can be executed on fine structure. The coarse pritirochny structure should be applied only in case of detection of traces of deep development or a strong burn-out of saddles. In this case the head of cylinders and valves should be handed over on check to the skilled expert to define whether it is necessary to perezenkovat saddles, or to replace inserts of saddles.
4. Before grinding in put a head of cylinders on a plain surface, combustion chambers up.
5. Apply a thin film of pritirochny paste on a saddle facet. Carry out grinding in, turning adaptation on 180 ° in both parties and periodically raising the valve for uniform redistribution of abrasive material.
6. If the rough structure is applied, then grinding in comes to an end after formation of a monotonous opaque corbel on facets of the valve and a saddle. Wipe the valve and a saddle from the remains of paste and continue grinding in on fine structure. Grinding in is considered complete at education on facets of the valve and a saddle of a uniform continuous corbel of grayish color. Further grinding in is not allowed as because of excessive development of a saddle the subsequent its repair can become impossible.
7. After the end of grinding in of all valves carefully wash out all details solvent.