Mazda 626

1991-1998 of release

Repair and operation of the car

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 dismantle of the engine from the car
      + 3.5.4. Capital repairs of the engine
      3.5.5. Check by means of the vacuum measuring instrument
      3.5.6. Check of a compression
      3.5.7. Methods of dismantle of the engine
      3.5.8. Removal and installation of the engine
      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 bent 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 bent 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 bent shaft
      3.5.24. Installation of a back epiploon of a bent shaft
      3.5.25. Installation of pistons and rods
   + 3.6. Diesel engine 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 half shafts
+ 9. Brake system
+ 10. Running gear
+ 11. Body
+ 12. Electric equipment
+ 13. Electrical circuitries
+ 14. Useful tips


3.5.6. Check of a compression


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

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

Compression pressure measuring instrument

The hose of the 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 bent shaft of the engine a starter. After one or two turns pressure of compression has to will increase to the maximum mark, and then to be stabilized. Write down the received result.

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

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

If when conducting check you have doubts, address skilled experts.

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

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

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

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

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

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