| TIBURON(GK) >2007 > G 2.0 DOHC > Engine Mechanical System > General Information>Repair procedures |

INSPECTION
COMPRESSION
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 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 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. | Turn the crankshaft pulley, and align its groove with timing mark "T" of the timing belt cover.
5. | Temperarily loosen tensioner pulley(A) by center bolt.
6. | Timing belt tension adjusting.
(1) | Rotate crankshaft in regular direction (clock wise view from front) through angle equivalent to two teeth (18°) of camshaft sprocket(A).
(2) | Using a hex wrench, turn the adjust counterclockwise to make the indicator of the arm(A) located at the center of the base notch.
(3) | Tightening tensioner bolt.
Tightening torque Tensioner bolt 22.6 ~ 28.4Nm (2.3 ~ 2.9kgf.cm, 16.6 ~ 21.0lbf.ft)
(4) | Recheck the belt tension, When the tension side of timing belt is pushed horizontally with a moderate force [approx. 2kg (20N, 5lb)], the timing belt cog end sags in approx. 4 ~ 6mm (0.16 ~ 0.24in.)
7. | Turn the crankshaft two turns in the operating direction (clockwise) and realign crankshaft sprocket and camshaft sprocket timing mark.
8. | Install the timing belt upper cover(A) with 4bolts(B).
Tightening torque 7.8 ~ 9.8Nm (0.8 ~ 1.0kgf.m, 5.8 ~ 7.2lb-ft)
9. | Install RH front wheel.
10. | 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. (See procedure in step (6))
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.)