BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

+ 1. The maintenance instruction
+ 2. Maintenance service
- 3. The engine
   + 3.1.2. Specifications
   - 3.2. Dismantle and engine major repairs
      3.2.2. Specifications
      3.2.3. Major repairs – the general instructions
      3.2.4. Compression check in engine cylinders
      3.2.5. Major repairs – broad-brush observations
      3.2.6. Diagnostics of the engine with the help вакууметра
      3.2.7. Major repairs – alternatives
      3.2.8. Dismantle of the power unit
      3.2.9. Removal and engine installation
      3.2.10. An order of dismantling of the engine
      3.2.11. Dismantling of a head of the block of cylinders
      3.2.12. Clearing and check of a head of cylinders and details клапанного the mechanism
      3.2.13. Repair of valves
      3.2.14. Assemblage of a head of the block of cylinders
      3.2.15. Removal of pistons and rods
      3.2.16. Dismantle коленвала
      3.2.17. An intermediate shaft (only engine M20)
      3.2.18. Clearing of the block of cylinders
      3.2.19. Check of a condition of the block of cylinders
      3.2.20. Хоннингование cylinders
      3.2.21. Check of a condition of pistons and rods
      3.2.22. Condition check коленвала
      3.2.23. Check radical and шатунных bearings
      3.2.24. An engine assembly order
      3.2.25. Installation of piston rings
      3.2.26. Installation of an intermediate shaft
      3.2.27. Installation коленвала and check of backlashes in radical bearings
      3.2.28. Installation of a back epiploon
      3.2.29. Installation of rods and pistons, check of backlashes in шатунных bearings
      3.2.30. Start-up of the engine after repair and обкатка
   + 3.3. An engine electric equipment
+ 4. Cooling system
+ 5. Heating and ventilation
+ 6. Fuel system
+ 7. An exhaust system
+ 8. Transmissions
+ 9. Coupling
+ 10. Brake system
+ 11. A running gear
+ 12. A body
+ 13. An electric equipment
+ 14. A good advice

3.2.12. Clearing and check of a head of cylinders and details клапанного the mechanism

Careful clearing of a head of the block of cylinders and its details with the subsequent check will allow to estimate amount of works on repair клапанного the mechanism.

The prevention

If the engine often overheated, most likely the head of cylinders could warp, carefully check up presence of signs of deformation of a head.


1. Clear demountable planes of a head of cylinders of the consolidation rests.
2. Remove a scum from channels of a cooling liquid.
3. Clean all apertures.
4. Banish all carving apertures.
5. Wash out a head of cylinders solvent and blow compressed air.
6. Remove massive adjournment of a deposit from valves. At clearing do not mix valves from different complete sets of the removed details.

The prevention

Before drawing a conclusion on necessity of repolishing of details, necessarily execute all checks described below procedure.

Deterioration of the valve

1. An end face

2. Проточка under crackers

3. A core (a part with the least deterioration)

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

5. A facet

6. A corbel

Head of cylinders
1. Attentively examine a head, check up presence of cracks, traces of penetration of a cooling liquid and other damages. At detection of cracks a head of cylinders replace (preliminary consult in car-care centre).
2. Check up deformation of a demountable plane of a head of cylinders. If it is revealed that the curvature of a demountable plane is more than norm a head it is necessary прошлифовать. If deformation of a demountable plane is that that the height of a head after polishing becomes less standard a head replace.
3. Check up a condition of saddles of valves. At presence питтинга (poles), cracks, traces прогара head repair in a car-care centre workshop is required.
4. The indicator check up a backlash of valves in directing plugs. For this purpose the valve insert into the corresponding directing plug so that it acted on 2,0 mm from a saddle, and shake here and there. Size total люфта divide half-and-half. If there are doubts concerning a condition of plugs it is necessary to hand over a head in car-care centre for more detailed check.
5. Check up presence on valves of cracks, burn-out traces, задиров and a fillet formed owing to deterioration on cores. Valve turn check up its bend. Check up development of end faces. At detection of any signs of deterioration it is necessary to repair or replace the valve.

6. Measure width (1) corbels of the valve. If width less limiting the valve (2) replace.
7. Check up deterioration presence at spring end faces. Rough check of a condition of a spring can be spent by comparison of length of a spring in a free condition from the standard.

8. Check up a deviation of a spring from a vertical by means of a square.
9. If at least one of springs is damaged, has the raised deviation from a vertical, or has lost elasticity replace all springs in the complete set. Check up presence of cracks on crackers of valves and plates of springs. Replace a detail at detection of the slightest damages.
Коромысла (М10 and М20)
10. To the greatest deterioration are exposed коромысла final valves, they should be checked especially carefully.
Check up on коромыслах those places which adjoin to cams of a cam-shaft and a valve end face.
11. Check up люфт коромысел on platens. If the indicator indication at rocking коромысла exceeds norm replace the plug коромысла or the platen (or both these details, is it is possible to check up, having placed коромысло on obviously not worn out part of the platen).
Platens коромысел (М10 and М20)
12. Check up presence on the platen of wear tracks, задиров and other damages. At fillet detection in the places corresponding to edges коромысел, the platen replace.
Hydropushers and levers (М40)
13. Check up a condition of working surfaces of levers, presence on them of traces of deep development. At detection of signs of deterioration on pushers and a cam-shaft, replace pushers and a cam-shaft.
14. Check up a condition of rubbing surfaces of hydropushers. If the raised noise from outside at least one pusher was marked at engine work replace all pushers in the complete set. Pushers vary also at any signs of a doubtful condition.
15. Check up presence on cams of a cam-shaft of traces of deep development, задиров and poles. Check up height of each cam. If the sizes of cams of inlet or final valves differ more than on 0,08 mm, or at detection of any signs of deterioration, a cam-shaft replace.
16. Check up a condition of basic necks, presence on them of deep development, задиров and poles. At detection of deterioration of necks replace a head of cylinders as beds under necks will be worn obviously out.

The prevention

If the unique reason on which the head of cylinders is subject to replacement, insignificant deterioration of necks of a cam-shaft address in car-care centre BMW for consultation concerning repair possibility is.

17. Define backlashes in basic necks of a cam-shaft, having measured diameters of basic necks and diameters of beds under necks in a head of cylinders (on engine M40 for this purpose establish covers of basic necks). If the backlash differs from norm a cam-shaft or a head of cylinders replace (preliminary address in car-care centre BMW for consultation).