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
      3.1.3. Kinds of the repair work which is carried out without dismantle of the engine
      3.1.4. An order of installation of the piston of 1st cylinder in ВМТ a compression step
      3.1.5. A cover of a head of cylinders
      3.1.6. A soaking up collector
      3.1.7. A final collector
      3.1.8. Covers of a chain of a drive of a cam-shaft (engine M10)
      3.1.9. A chain and asterisks (engine M10)
      3.1.10. Covers of a gear belt (engines M20 and М40)
      3.1.11. A gear belt and cam-shaft asterisks (engines M20 and М40)
      3.1.12. Forward epiploons
      3.1.13. A head of cylinders
      3.1.14. The pallet
      3.1.15. The oil pump
      3.1.16. A flywheel (a leading disk)
      3.1.17. A back epiploon коленвала
      3.1.18. Engine mount details
   + 3.2. Dismantle and engine major repairs
   + 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

3.1.11. A gear belt and cam-shaft asterisks (engines M20 and М40)

The prevention

Before asterisk removal on engine M40 the special adaptation for cam-shaft fixing is necessary.


1. Disconnect the battery from weight.
2. Remove covers of a gear belt.
3. On engine M40 merge cooling liquid (subsection 2.31 see) and remove the thermostat (subsection 4.4 see).
4. Establish the piston of 1st cylinder in ВМТ a compression step (subsection 3.1.4 see).
The prevention

After installation of the piston of 1st cylinder in ВМТ a step of compression and removal of a chain rotation коленвала is not supposed, serious breakages because of impact of heads of valves with the bottoms of pistons otherwise are possible.

5. On engine M20 check up label combination on a sock nave коленвала with a label on a back cover of a gear belt.
6. The label on a cam-shaft should be opposite to cast risks on a head of cylinders.
7. On engine M40 put ориентационные risks on asterisk of a cam-shaft and a back cover which will be used at assemblage.
8. On engine M20 release roller bolts натяжителя and displace натяжитель towards the pump of a cooling liquid, having weakened a belt. Tighten bolts.
9. On engine M40 release a nut натяжителя and turn натяжитель clockwise, having weakened a belt. Tighten a nut.
10. Check up presence on a belt of a directional marker of rotation, at its absence put a label (if the removed belt in a normal state and is established again).
The prevention

The belt is recommended to be changed at each removal, irrespective of its condition. On engine M40 it is necessary to replace a belt after its each easing. Keep in mind that at removal of a belt from an asterisk коленвала it is necessary to make considerable effort.

11. Remove a belt from asterisks.
12. Turn away a bolt of an asterisk of a cam-shaft for what fix its leather tape or the old gear belt dressed on teeths and compressed by flat-nose pliers.
13. Fix a cam-shaft from проворачивания.

The prevention

On engine M40 the asterisk is fixed on a cam-shaft nonrigidly, шпонка supposes shaft moving on some degrees. Asterisk fixing is provided on конусной shaft parts at a bolt tightening.

14. The adaptation for fixing should cover a 4-faced neck of a cam-shaft about 1st cylinder at right angle to a head of cylinders.
15. If necessary fix коленвал and turn away a bolt of a nave of a sock коленвала. For fixing коленвала adaptation BMW 112150 (engine M20) or 112170 (М40) which maintains the considerable effort demanded for отворачивания a bolt is used. It is necessary to notice that adaptation BMW 112170 fastens to a head of cylinders and fixes a flywheel. Therefore it can be applied only in the event that the check point or the engine are removed.
16. On engines with a two-level nave of a sock коленвала after отворачивания a bolt it is necessary to remove a stripper an asterisk for what it is necessary to turn a pulley bolt коленвала on 3 turns and to use it as a support for a stripper bolt.

Typical damages of a gear belt

1. A wipe of a cover and a rubber exposure

2. Stratification

3. Loss of teeths

4. Deterioration of persistence of a surface of teeths

5. Occurrence of fibres of a basis

6. An end face rounding off


1. Check up a belt condition, replace at detection of any damages. Check up a condition of teeths of asterisks, in case of non-uniform deterioration an asterisk replace.

The prevention

At replacement of these details address in car-care centre. The asterisk, a belt and a roller натяжителя engine M20 of late releases have marks Z127. These details should be established in the complete set if details of former releases are absent.

2. Check up freedom of rotation of a roller натяжителя and a spring condition. At belt replacement the roller varies also.


1. On engine M20 establish a roller with a spring so that the belt could be dressed freely.
2. Establish asterisks upside-down. On engine M40 tighten a bolt of an asterisk of a cam-shaft with the moment 1–3 Н.м., having turned an asterisk clockwise against the stop.
3. At installation of the removed belt сориентируйте it on the put label specifying a direction of rotation.
4. Dress a belt on asterisks, having begun with an asterisk коленвала.
5. Dress a belt on a roller натяжителя.
6. On engine M20 release bolts натяжителя.
7. On engine M20 will make small effort under a roller натяжителя, having convinced of moving freedom плунжера and in creation by a spring of a tension of a belt. Bolts thus not to tighten.
8. On engine M40 release a roller nut натяжителя and turn a roller a 6-faced key counter-clockwise to a belt tension. A belt tension supervise on a special dynamometer, the normal tension corresponds 32 (2) to divisions of a scale of the index.
9. Comprehensible accuracy of a tension is reached by application of a 6-faced key with a spring steelyard. A steelyard arrange as it is shown in a picture, otherwise indications will be inexact that the roller натяжителя is strengthened on the clown. The shoulder And a key should have length of 85 mm, and the effort is made a steelyard 2,0 кГс.
10. Check up combination of all labels.
11. Turn коленвал on 2 turns.
12. On engine M20 release roller bolts натяжителя and tighten with the set moment.
13. On engine M40 release a roller nut натяжителя and tighten a bolt of an asterisk of a cam-shaft.
14. Be convinced of combination of all labels. If combination of labels is broken, remove a belt and repeat procedure of clothing of a belt.
15. Further assemblage is carried out upside-down.