Mazda Training manual - part 20

Powertrain Engines 

Valve Train 

• 

The camshaft is driven by a timing belt, which has to be replaced every 120,000 km. 

 

L1001.4_01066 

 

1 

Camshaft pulley 

7 

Crankshaft pulley 

2 

Camshaft 

8 

Timing belt tensioner 

3 

Rocker arm 

9 

Tensioner pulley 

4 

Rocker bridge 

10 

Water pump pulley 

5 

Fuel high-pressure pump pulley 

11 

Timing belt 

6 Idler 

pulley 

  

Curriculum Training 

01-67 

Engines Powertrain 

Timing Belt Tensioner 

• 

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

• 

The timing chain tensioner operates using a hydraulic mechanism, which also 
compensates the increased belt tension due to heat expansion of the engine 
components. 

 

L1001.4_01120 

 

1 Timing 

belt 

6 Plunger 

2 Tensioner 

pulley 

7 Spring 

3 

Plunger spring 

8 

Tensioner rod 

4 

Pressure chamber 

9 

Tensioner arm 

5 Check 

valve 

  

 

01-68 Curriculum 

Training 

Powertrain Engines 

• 

When replacing the timing belt, the timing belt tensioner has to be checked as following 
(refer to the workshop manual for details): 

– 

Measure the tensioner rod projection length. 

– 

Inspect the tensioner for oil leakage. 

– 

Verify the thrust/resistance of the tensioner. 

 

NOTE:  If the tensioner rod projection length and/or tensioner thrust/resistance exceeds the 

specification and/or there is an oil leakage, replace the timing belt tensioner. 

 
• 

Before installing the timing belt tensioner, the tensioner rod has to be pushed down and 
secured by inserting a locking pin with 1.5 mm diameter (refer to the workshop manual 
for details). 

 

NOTE:  Placing the timing belt tensioner horizontally while pushing the tensioner rod can 

cause oil leakage and damage the automatic tensioner. 

 

NOTE:  To prevent damage to the timing belt tensioner, the tensioner rod has to be pushed 

slowly with a force not greater than the specified 235 N. The tensioner rod must not 
touch the bottom. 

 

L1001.4_01067 

 

1 

Tensioner rod 

3 

Locking pin  

2 

Tensioner rod projection length 

 

 

 

Curriculum Training 

01-69 

Engines Powertrain 

Valve Timing 

• 

For verifying or adjusting the valve timing the timing marks have to be aligned as shown 
below (refer to the workshop manual for details). 

• 

Before installing the timing belt the camshaft pulley must be fixed to the cylinder head 
using a bolt (M8 x 1.25). In addition, the fuel high-pressure pump pulley has to be locked 
against rotation with the aid of the FIP (Fuel Injection Pump) repair kit (part no. RFY1-13-
SMO). 

 

NOTE:  In order to prevent damage to the camshaft pulley, the detent bolts do not have to be 

fully tightened. 

 

L1001.4_01068 

 

1 

Timing mark (camshaft pulley) 

4 

Timing mark (crankshaft pulley) 

2 

Timing mark (fuel high-pressure pump 
pulley) 

5 

Hole for detent bolt 

3 FIP 

repair 

kit 

  

 

01-70 Curriculum 

Training