Mazda 626

1991-1998 of release

Repair and car operation

Mazda 626

+ 1. Maintenance instruction
+ 2. Maintenance
- 3. Engines
   + 3.1. Petrol engines (1,6 and 1,8 liters)
   + 3.2. Petrol 4-cylinder engine (2 liters)
   + 3.3. Petrol V6 engine (2,5 liters)
   + 3.4. Partition of engines (1,6 and 1,8 liters)
   - 3.5. Partition of engines (2,0 and 2,5 liters of V6)
      3.5.1. Introduction
      + 3.5.2. Technical characteristics
      3.5.3. Repair work without engine dismantle from the car
      + 3.5.4. Major maintenance of the engine
      3.5.5. Check by means of a vacuum measuring instrument
      3.5.6. Compression check
      3.5.7. Methods of dismantle of the engine
      3.5.8. Removal and engine installation
      3.5.9. Engine partition
      3.5.10. Partition and check of a head of cylinders
      3.5.11. Valves
      3.5.12. Assembly of a head of cylinders
      3.5.13. Removal of pistons and rods
      3.5.14. Removal of a cranked shaft
      3.5.15. Check of the block of cylinders
      3.5.16. Honingovaniye of cylinders
      3.5.17. Check of pistons and rods
      3.5.18. Check of a cranked shaft
      3.5.19. Check and selection of radical bearings and bearings of rods
      3.5.20. Check of camshafts and pushers
      3.5.21. Engine assembly order
      3.5.22. Installation of piston rings
      3.5.23. Installation of a cranked shaft
      3.5.24. Installation of a back epiploon of a cranked shaft
      3.5.25. Installation of pistons and rods
   + 3.6. Diesel engine of 2,0 liters
   + 3.7. Systems of electric equipment of the engine
+ 4. Heating and ventilation
+ 5. Fuel system
+ 6. Exhaust system
+ 7. Transmissions
+ 8. Coupling and semi-axes
+ 9. Brake system
+ 10. Running gear
+ 11. Body
+ 12. Electric equipment
+ 13. Electroschemes
+ 14. Good advice

3.5.6. Compression check


Disconnect ignition system, having disconnected a wire of a high voltage of system of ignition from a cover of the distributor of ignition, and having earthed it on the block of cylinders.

Connect the device for compression measurement to an opening of a spark plug of the N1 cylinder.

Measuring instrument of pressure of compression

The hose of a measuring instrument is connected to an adapter, and the adapter is twisted in a spark plug opening.

Completely open a butterfly valve and scroll a cranked shaft of the engine a starter. After one or two turns pressure of compression should will raise to the maximum mark, and then to be stabilized. Write down the received result.

Carry out similar check with other cylinders and write down the received indications.

Pressure in all cylinders should be identical. The difference more than in the 2nd bar between any two cylinders means malfunction. In the serviceable engine pressure should accrue quickly. The small pressure of the first step which is gradually raising at the subsequent steps, specifies that piston rings are worn-out. Small pressure of the first step which does not accrue at the subsequent steps, indicates leak in valves or on the punched laying of a head. Deposits on the lower parts of valves can as to become the reason of a low compression.

If at carrying out check you have doubts, address to skilled experts.

If pressure, in any cylinder too low, carry out the following check to establish the reason. Pour in a teaspoon of pure engine oil in the cylinder through an opening of a spark plug and repeat pressure check.

If after oil addition pressure of compression increased, it means that the piston or the cylinder is worn-out. If pressure did not increase, means, the reason in the worn-out or scorched valves or in the punched laying of a head of cylinders.

Low pressure in two next cylinders practically always means that between them head laying is punched.

If in one of cylinders pressure approximately for 20 % is lower, than in the others and the engine badly idles, it means that the reason, probably, the worn-out cam of a camshaft is.

If pressure too big, most likely, walls of chambers of combustion are covered with coal deposits.

After completion of check screw in spark plugs on places and connect ignition system.