| TIBURON(GK) >2008 > G 2.0 DOHC > Engine Mechanical System > General Information>Repair procedures |

INSPECTION
COMPRESSION PRESSURE
If the there is lack of power, excessive oil consumption or poor fuel economy, measure the compression pressure.
1. | Warm up and stop engine. Allow the engine to warm up to normal operating temperature.
2. | Remove ignition coils. (Refer to Ignition system in EE Group)
3. | Remove spark plugs. Using a 16mm plug wrench, remove the 4 spark plugs.
4. | Check cylinder compression pressure.
(1) | Insert a compression gauge into the spark plug hole.
(2) | Fully open the throttle.
(3) | While cranking the engine, measure the compression pressure.
Always use a fully charged battery to obtain engine speed of 250 rpm or more.
(4) | Repeat steps (1) through (3) for each cylinder.
This measurement must be done in as short a time as possible.
Compression pressure : 1,420kPa (14.5kgf/cm², 206psi) Minimum pressure : 1,270kPa (13kgf/cm², 184psi) Difference between each cylinder : 100kPa (1.0kgf/cm², 15psi) or less
(5) | If the cylinder compression in 1 or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (1) through (3) for cylinders with low compression.
A. | If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged.
B. | If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket.
5. | Reinstall spark plugs.
6. | Install ignition coils. (Refer to Ignition system in EE Group)
Timing belt tension adjustment
1. | Remove the engine cover(A).
2. | Remove RH front wheel.
3. | Remove the 4bolts(B) and timing belt upper cover(A).
4. | Slacken the tensioner bolt.
When check the timing belt tension or install the timing belt tensioner, must it the engine oil temperature is between 15°C(59°F) and 25°C(77°F).
5. | Using a hex wrench, turn the adjuster counterclockwise to make the indicator of the arm (A) located at the center of the base notch.
Do not rotate the adjuster clockwise. It will result in auto tensioner's functional problem.
6. | Tightening tensioner bolt with fixing the indicator not to move.
Tightening torque Tensioner bolt : 22.6 ~ 28.4Nm (2.3 ~ 2.9kgf.m, 16.6 ~ 21.0lb-ft)
7. | Turn the crankshaft two revolutions in the operating direction (clockwise) and check that the indicator is in the center of base.
8. | If the indicator is not located at the center of base, slacken the bolt and repeat the above procedure.
9. | Install the timing belt upper cover (A) with the four bolts (B).
Tightening torque : 7.8 ~ 9.8Nm (0.8 ~ 1.0kgf.m, 5.8 ~ 7.2lb-ft)
10. | Install RH front wheel.
11. | Install engine cover(A).
VALVE CLEARANCE INSPECTION AND ADJUSTMENT MLA (MECHANICAL LASH ADJUSTER)
Inspect and adjust the valve clearance when the engine is cold (Engine coolant temperature : 20°C) and cylinder head is installed on the cylinder block.
1. | Remove the engine cover.
2. | Remove the upper timing belt cover.
(1) | Loosen the upper timing cover bolts and then remove the cover.
3. | Remove the cylinder head cover.
(1) | Disconnect the spark plug cables and do not pull on the spark plug by force.
Pulling on or bending the cables may damage the connductor inside.
(2) | Disconnect the P.C.V hose(A) and the breather hose(B) from the cylinder head cover.
(3) | Disconnect the accelerater cable(A) from the cylinder head cover.
(4) | Loosen the cylinder head cover bolts(B) and then remove the cover(A) and gasket.
4. | Set No.1 cylinder to TDC/compression.
(1) | Turn the crankshaft pulley and align its groove with the timing mark "T" of the lower timing belt cover.
(2) | Check that the hole of the camshaft timing pulley(A) is aligned with the timing mark of the bearing cap. If not, turn the crankshaft one revolution (360°)
5. | Inspect the valve clearance.
(1) | Check only the valve indicated as shown. [No. 1 cylinder : TDC/Compression] measure the valve clearance.
A. | Using a thickness gauge, measure the clearance between the tappet shim and the base circle of camshaft.
B. | Record the out-of-specification valve clearance measurements. They will be used later to determine the required replaement adjusing shim.
Valve clearance SpecificationEngine coolant temperature : 20°C [68°F]Intake : 0.20mm (0.0079in.)Exhaust : 0.28mm (0.0110in.) LimitIntake : 0.12 ~ 0.28mm (0.0047 ~ 0.0110in.)Exhaust : 0.20 ~ 0.38mm (0.0079 ~ 0.0150in.)
(2) | Turn the crankshaft pulley one revolution (360°) and align the groove with timing mark "T" of the lower timing belt cover.
(3) | Check only valves indicated as shown. [NO. 4 cylinder : TDC/compression]. Measure the valve clearance.
6. | Adjust the intake and exhaust valve clearance.
(1) | Turn the crankshaft so that the cam lobe of the camshaft on the adjusting valve is upward.
(2) | Using the SST(09220-2D000), press down the valve lifter and place the stopper between the camshaft and valve lifter and remove the special tool.
(3) | Remove the adjusting shim with a small screw driver(A) and magnet(B).
(4) | Measure the thickness of the removed shim using a micrometer.
(5) | Calculate the thickness of a new shim so that the valve clearance comes within the specificified value.
Valve clearance (Engine coolant temperature : 20°C) T : Thickness of removed shim A : Measured valve clearance N : Thickness of new shim Intake : N = T + [A - 0.20mm(0.0079in.)] Exhaust : N = T + [A-0.28mm (0.0110in.)]
(6) | Select a new shim with a thickness as close as possible to the caculated value. [Refer to the Adjusting shim selection chart]
Shims are available in 20size increments of 0.04mm (0.0016in.) from 2.00mm (0.079in.) to 2.76mm (0.1087in.)
(7) | Place a new adjusting shim on the valve lifter.
(8) | Using the SST(09220-2D000), press down the valve lifter and remove the stopper.
(9) | Recheck the valve clearance.
Valve clearance (Engine coolant temperature : 20°C) [Specification] Intake : 0.20mm (0.0079in.) Exhaust : 0.28mm (0.0110in.) [Limit] (After adjusting valve clearance) Intake : 0.17 ~ 0.23mm (0.0067 ~ 0.0091in.) Exhaust : 0.25 ~ 0.31mm (0.0098 ~ 0.0122in.)