Mazda Engine SKYACTIV-G 2.5. Manual - part 22

MECHANICAL 

01-10–72

2. Install the timing chain while aligning the marks on each sprocket and the timing chain as shown in the figure.

3. Install the tensioner arm.

4. Install the chain tensioner.

5. After installing the chain tensioner, remove the installed wire or paper clip, and then apply tension to the timing 

chain.

• If a new chain tensioner is used, remove the 

installed stopper.

6. Install the chain guide (No.1).

7. Verify that there is no looseness in the timing 

chain, and re-verify that each sprocket is in the 

specified location.

TIMING CHAIN 
ALIGNMENT MARK 
(YELLOW)

CRANKSHAFT SPROCKET 
TIMING CHAIN 
ALIGNMENT MARK

PIN

TIMING MARK

TIMING CHAIN 
ALIGNMENT MARK 
(ORANGE)

HYDRAULIC VARIABLE VALVE TIMING 
ACTUATOR TIMING CHAIN ALIGNMENT MARK

CYLINDER 
HEAD 
UPPER 
SURFACE

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STOPPER

LINK PLATE

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MECHANICAL 

01-10–73

01-10

8. Rotate the crankshaft clockwise two turns and inspect the valve timing.

Note

• The timing mark of SKYACTIV-G 2.5 is not completely parallel with the upper surface of the cylinder head.

CYLINDER 
HEAD 
UPPER 
SURFACE

KEY

PIN

TIMING MARK

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MECHANICAL 

01-10–74

Engine Front Cover Assembly Note

Note

• For a new engine front cover, the positioning 

pins in the two locations shown in the figure 

project to the outside of the engine.

1. If the engine front cover is newly replaced, tap the 

positioning pins in the two locations to the seal 

surface side.

2. Completely clean and remove any oil, dirt, sealant 

or other foreign matter that may be adhering to 

the engine front cover, cylinder head, and cylinder 

block.

3. When reusing the engine front cover installation 

bolts, clean any old sealant from the bolts.

Caution

• Apply the silicon sealant in a single, 

unbroken line.

• To prevent silicone sealant from 

hardening, adhere the engine front cover 

to the cylinder block within 10 min. after 

silicone sealant is applied. Tighten the 

installation bolts completely soon after 

adhering.

• Using bolts with the old seal adhering 

could cause cracks in the cylinder head 

and cylinder block.

POSITIONING PIN

A

VIEW FROM A

SEAL SIDE

ENGINE OUTSIDE

POSITIONING 
PIN

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WOOD SLAB

0—1 mm 
{0—0.03 in}

POSITIONING PIN

SEAL SIDE

ENGINE OUTSIDE

POSITIONING 
PIN

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OLD SEALANT

DAMAGE

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MECHANICAL 

01-10–75

01-10

4. Apply silicone sealant to the engine front cover as shown in the figure.

Bead thickness

A: 2—6 mm {0.1—0.2 in}

B: 4—6 mm {0.16—0.23 in}

C: 4—8 mm {0.2—0.3 in}

A

mm {in}

SEALANT

SEALANT

90

°

10 {0.39}

SECTION D-D

0.5

—

1.5 mm 

{0.02

—

0.05 in}

SEALANT

SEALANT

ENGINE FRONT 
COVER

A

10 {0.39}

10 {0.39}

10 {0.39}

10 {0.39}

10 {0.39}

32.5 {1.28}

10 {0.39}

B

C

B

B

C

B

B

C

B

B

C

B

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