Ford Fokus>> Engines>> Compression gauging>> Norms of a compression of engines
The engine                                            

The engine
Norm of a compression
1,4 l Zetec-SE                  
1,6 l Zetec-SE                  
1,8 l Zetec-E                    
2,0 l Zetec-E                    
1,8 l Endura-Turbodiesel
1,8 l Endura-DI-Turbodiesel
12-14 кПа
12-14 кПа
12-14 кПа
12-14 кПа
28-34 кПа
28-34 кПа

Maximum permissible value of size of a compression for petrol engines makes 10 кПа, for diesel engines — 24 кПа.
If you have the necessary equipment can measure a compression independently, however for this purpose the assistant who will turn a cranked shaft a starter is required to you. To begin with unscrew all spark plugs from a head of the block and be convinced that the valve are correctly exposed. During compression check on the petrol engine your assistant should press an accelerator and coupling pedal completely. At check of the diesel engine to press an accelerator pedal it is not necessary.
Start to check with 1st cylinder and further operate on an operating procedure of cylinders. At check define turns of a cranked shaft after which the maximum value of a compression will be established. Smooth increase of pressure in cylinders testifies to a good condition цилиндропоршневой groups. By experience, on the engine in a good condition the highest value of pressure is marked after 6—8 scrollings of a cranked shaft.
Before starting to measure a compression, be convinced that the starter is in a good condition and the storage battery is completely charged. This work in cylinders and character of noise he however is better to entrust the expert, in a difference of sizes of a compression can reveal following malfunctions:
- Noise in an inlet collector — leaky прилегание the inlet valve to a saddle;
- Noise from opened маслоналивной a mouth or a measuring instrument of level of oil — the worn out walls of cylinders or a crack of a head of the block;
- Noise from a final collector — leaky final valves.
If the size of a compression received as a result of measurements is less than norm, try to add a few engine oil in apertures under spark plugs (apertures under atomizers for a diesel engine) and repeat gauging. It will allow to reduce a backlash between the piston and the cylinder. If value does not change — pressure in the cylinder as a result of leaky прилегания valves to saddles or damage of a lining of a head. If the compression size has increased, it specifies in deterioration of piston rings or working surfaces of cylinders.
Compression measurement spend in a following order:
- Warm up the engine to working temperature, as a result выбирутся backlashes between moving details;
- Disconnect ignition (a contact socket 15), remove from spark plugs tips of wires and turn out all spark plugs;
- Brake the car a lay brake, establish the transmission lever in neutral position. Your assistant should press a pedal of coupling and an accelerator pedal;
- Insert a rubber cone of a measuring instrument of a compression into an aperture for a spark plug (for a diesel engine this aperture for atomizers) 1st cylinder, if necessary can use an adapter;
- Further your assistant scrolls a cranked shaft from 6 to 8 turns to receive the greatest size of a compression;

Fig. 164. The rubber cone of the device for a compression should close an aperture under a spark plug

Fig. 165. Indicators of the device for compression measurement

- Write down the received result. Repeat measurements for other cylinders (fig. 164 and 165).