Mazda Training manual — part 29

Powertrain Engines

Timing Belt Tensioner

•

An automatic timing belt tensioner is fitted to ensure optimum belt tension over the
service life of the engine.

•

For tensioning the timing belt, turn the tensioner with an Allen key until the pointer is
aligned with the corresponding mark on the housing, and tighten the bolt (refer to the
workshop manual for details).

L1001.4_01095

1

Housing with mark

3

Hexagonal hole for Allen key

2 Pointer

Curriculum Training

01-103

Engines Powertrain

Valve Timing

•

For verifying or adjusting the valve timing, the crankshaft timing peg (SST) has to be
installed in the cylinder block, and the camshaft timing peg (SST) in the cylinder head.

•

Depending on whether or not there is a hole for the crankshaft timing peg (SST) in the
bracket of the fuel high-pressure pump, the fuel high-pressure pump pulley must be
aligned in either of the two ways shown below (refer to the workshop manual for details).

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1

Hole for camshaft timing peg (SST)

3

Fuel high-pressure pump pulley aligned
with SST

2

Hole for crankshaft timing peg (SST)

4

Fuel high-pressure pump aligned without
SST

01-104 Curriculum

Training

Powertrain Engines

Mechanical (Y6 Engine)

Features

•

The mechanical system of the Y6 engine has the following features:

–

Belt and chain driven 16 valve DOHC engine

–

Valve train with automatic timing belt tensioner, roller cam followers and hydraulic
tappets

–

Vacuum pump driven by the exhaust camshaft

–

V-ribbed belt drive with automatic tensioner

Overview

L1001.4_01101

NOTE: Some of the components of the Y6 engine are very similar in construction and

operation to those of the Y4 engine. Therefore, this section only describes the
components which are new or differ from those of the Y4 engine.

Curriculum Training

01-105

Engines Powertrain

Cylinder Head

•

The cylinder head is composed of an upper and a lower part. Upper and lower cylinder
head are matched to each other, i.e. they cannot be replaced separately. If one of the
components exceeds the specification, the cylinder head must be replaced as a
complete unit.

•

There are no guide sleeves for locating the cylinder head upper part on the lower part.
For this reason, two guide studs (SST) are required for the installation of the upper
cylinder head (refer to the workshop manual for details).

•

The cylinder head gasket is available in five different thicknesses depending on the
piston protrusion. The gasket is marked respectively (refer to the workshop manual for
details).

•

The cylinder head bolts are torque-to-yield bolts, which must be tightened in several
stages (refer to the workshop manual for details.

NOTE: The cylinder head bolts must not be re-used.

NOTE: When sealing the area between the upper and lower part of the cylinder head using

silicon sealant, care must be taken that the oil supply bores are not blocked.

L1001.4_01103

1

Engine front side

4

Exhaust camshaft

2

Upper cylinder head

5

Lower cylinder head

3 Intake

camshaft

01-106 Curriculum

Training