Engine Mechanical: Overview Suzuki SX4 I рестайлинг

Engine Construction Description

The engine is water-cooled, in-line 4 cylinders, 4-stroke-cycle gasoline unit with its DOHC (Double Over Head Camshaft) valve mechanism arranged for "V" type valve configuration and has 16 valves (4 valves/one cylinder). The intake camshaft and exhaust camshaft are mounted over the cylinder head; They are driven by crankshaft through timing chain, and no push rod is provided in the valve train system.

Scheme 1

IMT (Intake manifold tuning) system varies effective length of intake pipe by opening and closing IMT valve in order to improve air volumetric efficiency.

As intake valve in cylinder head is opened and closed repeatedly, intake air pulsation always exists. If intake valve is opened when air pressure is momentarily maximum, intake air volumetric efficiency is increased. This momentary maximum air pressure depends on effective intake pipe length.

When IMT valve is fully open [A]

The effective intake pipe length is shorter. Engine torque between middle and high engine speed ranges is improved, while it drops between low and middle engine speed ranges.

When IMT valve is totally closed [B]

The effective intake pipe length is longer. Engine torque between middle and high engine speed ranges drops, while it is improved between low and middle ranges.

IMT system utilizes this characteristic of engine. IMT valve is closed between low and middle engine speed ranges, and opened between middle and high engine speed ranges.

In this way, engine torque is improved in whole engine speed ranges.

Scheme 2

1. Warm up engine to normal operating temperature.
2. Stop engine after warm-up.
3. For CVT model, place select lever in "P" and apply parking brake. For M/T model, place gear shift lever in "Neutral" and apply parking brake.
4. Remove engine cover. Refer to «Air Cleaner Assembly Removal and Installation»(ref-514568-S42483472292012112100000) .
5. Remove all ignition coils and spark plugs.
6. Disconnect all fuel injector connectors.
7. Install special tools into spark plug hole. Special Tool 09915-64512 09915-64530 09915-67010
8. Depress accelerator pedal all the way to fully open throttle. NOTE: For M/T model, disengage clutch to lighten starting load on engine, and depress accelerator pedal all the way to fully open throttle.
9. Crank engine with fully charged battery, and read the highest pressure on compression gauge. NOTE: For measuring compression pressure, crank engine at least 200 rpm by using fully charged battery. If measured compression pressure is lower than limit value, check installation condition of special tool. If the measured compression pressure of particular cylinder is lower than limit, add a bit of engine oil into the cylinder through the spark plug hole, and then repeat the compression check. If the compression pressure increases after adding engine oil, there is possibility of the following cause. The pressure leakage is caused by worn piston rings or worn cylinder. If the compression pressure does not increase significantly, there is possibility of the following causes. Incorrect valve timing. The pressure leakage is at the valves and the valve seats. The pressure leakage is at the cylinder head gasket. Compression pressure Standard: 1,400 kPa (14.3 kgf/cm 2 , 203 psi) Limit: 1,100 kPa (11.2 kgf/cm 2 , 160 psi) Max. difference between any two cylinders: 100 kPa (1.02 kgf/cm 2 , 14.5 psi)
10. Carry out Steps 7 ) through 9 ) on each cylinder.
11. Install spark plugs and ignition coil assemblies.
12. Connect fuel injector connectors.
13. Install engine cover.

Scheme 3

1. Warm up engine to normal operating temperature.
2. For CVT model, place select lever in "P" and apply parking brake. For M/T model, place gear shift lever in "Neutral" and apply parking brake.
3. Remove engine cover. Refer to «Air Cleaner Assembly Removal and Installation»(ref-514568-S42483472292012112100000) .
4. Remove PCV hose (1) from PCV valve (2).
5. Connect special tool to PCV hose (1). Special Tool (A): 09915-67311
6. Close PCV valve (2) using tape (3) or the like.
7. Start engine and turn off all electric loads.
8. Read vacuum gauge at specified idle speed. Vacuum specification (at sea level) Standard: -65 kPa (-0.66 kgf/cm 2 , -9.43 psi, -0.65 bar) or less at specified idle speed
9. After checking, disconnect special tool from PCV valve.
10. Peel off tape from PCV hose.
11. Connect PCV hose to PCV valve.
12. Install engine cover.