1.3 Cylinder head

MLA (Mechanical Lash Adjuster)

Comparison between mla and hla

Items	MLA	HLA
Stand for	Mechanical Lash Adjuster	Hydraulic Lash Adjuster
Structure
Description	Valve clearance can be manually adjusted by shims.	Valve clearance is automatically adjusted by oil pressure as zero according to the temperature and the wear.
Advantage	Reduced fuel consumption app. 3.6% Reduced cost Improved durability	Stable valve overlap and idle Reduced noise Maintenance free

* Reason why the fuel consumption with MLA is reduced

1. Reduced friction of camshaft

   1. Friction is reduced while the camshaft pushes the lash adjuster because spring force can be reduced.

   2. Friction is reduced while the camshaft does not contact with lash adjuster.

   3. Friction is reduced by smooth surface of MLA

2. Reduced the driving force of the oil pump because of less oil flow.

Valve clearance adjustment

1. Set #1 cylinder to TDC compression

2. Check TDC position of camshaft

3. Check the clearance for

#1 intake valve, exhaust valve

#2 intake valve,

#3 exhaust valve

4. Turn the crank shaft one revolution

5. Check the clearance for

#2 exhaust valve,

#3 intake valve

#4 intake valve, exhaust valve

6. If the valve clearance is not within specification,

replace the adjusting shim with SST.

Specification (20ºc)

Intake 0.12 ~ 0.28mm

Exhaust 0.2 ~ 0.36mm

7. Refer to the adjusting shim selection chart of

the shop manual.

SST (Special Service Tool)

How to replace the shim?

1. T urn the crankshaft so that the cam lobe of

the camshaft on the adjusting valve is upward

2. Using the special tool (09220 - 2D000), press

down the valve lifter and place the stopper

between the camshaft and valve lifter and

remove the special tool

3. R emove the adjusting shim with a small screw

driver and magnet.

4. Measure the thickness of the removed shim

using a micrometer.

5. Select a new shim from the shim selection

chart of the shop manual.

[NOTE]

Shims are available in 20 size increments of 0.04 mm (0.0016 in.) from 2.00 mm (0.079 in.) to 2.76 mm (0.1087 in.)

6. Place a new adjusting shim on the valve lifter.

7. Using the special tool (09220 - 2D000), press down the valve lifter and remove the stopper.

8. Recheck the valve clearance.

[Specification at 20°C]

Intake : 0.17 - 0.23 mm (0.0067 - 0.0091 in.)

Exhaust : 0.25 - 0.31 mm (0.0098 - 0.0122 in.)

1.4 Cylinder block

Piston and connecting rod

Crankshaft

1 .5 Cooling system

Fan control relays

1.6 Lubrication system

1.7 Fuel system

Returnless fuel system is used for TUCSON to reduce the vapor gas from the fuel tank.

The fuel pump module consists of pump, filter, regulator and fuel level gauge.

Fuel pressure is maintained by regulator, which is located in the fuel pump module.

Fuel pressure : 3.5kg/cm³

Fuel pump module

1.8 Ignition system

TUCSON equips 2 coil ignition system. The ignition coils are controlled by ECM directly.