Variable Valve Timing Unit - Checking & Adjusting (Coupe): Other Volvo C70 I

Variable valve timing unit, checking and adjusting (B6XX4T (1999-2001))

Special tools

9995451

9995452

Installing and adjusting the variable valve timing unit/timing gear pulley on the camshaft

Note. This procedure must be carried out with precision as any deviation could generate a fault symptom.

Scheme 869

Remove the starter motor mounting screws. Pull out the starter motor and put it aside. Remove the plug of the gauge hole. Rotate the crankshaft slightly clockwise. Install: 9995451 . Make sure that it bottoms against the engine block.

Scheme 870

Turn the crankshaft counterclockwise to its stop against the crankshaft adjustment tool. Check that the marking on the crankshaft timing gear pulley aligns with the marking on the oil pump.

Scheme 871

Note. Some engines have double VVT units/belt pulleys. If this is the case, the method is to be performed on both.

Note. Oil the center screw before installation.

Press the variable valve timing unit/timing gear pulley onto the camshaft. Install the center screw (1) that holds the variable valve timing unit to the camshaft. Do not tighten yet .

Slacken off, but do not remove the screws (2) which secure the timing gear pulley to the variable valve timing unit.

Position the upper timing cover.

Scheme 872

Turn the timing gear pulley so that the screws at the oval holes are in the limit position. Continue turning clockwise until the timing gear pulley's marking is 1 tooth before the marking on the upper timing cover.

Check that the timing gear pulley is still in the limit position in the oval holes.

Tighten the center screw (1) in the VVT unit to 120 Nm .

Check that the variable valve timing unit does not rotate when tightening. Install the center plug and tighten to 35 Nm .

Install the belt pulley on the intake camshaft : Install the belt pulley on the intake camshaft with three screws; do not tighten yet .

Scheme 873

Turn the timing gear pulley to the marking. Check that the markings on the timing gear pulley/intake camshaft and upper timing cover correspond.

Installing the timing belt

Install the belt in the following order

1. the belt pulley on the crankshaft
2. the idler pulley
3. cam wheel, intake camshaft
4. water pump
5. belt tensioner.

Scheme 874

Turn the variable valve timing unit clockwise to the stop.

Note. Hold the VVT unit fixed in the limit position clockwise when the belt if fitted.

Check that the markings on the belt pulley and the upper timing cover align.

Scheme 875

Fit the timing belt over the exhaust camshaft's cam wheel.

Variable valve timing unit, checking and adjusting (B5234T3; 1998-2002)

For B5XX4TX (1999-2001) . See Variable valve timing unit, checking and adjusting .

For B5XX4TX (2002-) . See Variable valve timing unit, checking and adjusting .

For B5244S6 . See Variable valve timing unit, checking and adjusting .

For B6XX4T (1999-2001) . See Variable valve timing unit, checking and adjusting .

For B6XX4T (2002-2006) . See Variable valve timing unit, checking and adjusting .

Variable valve timing unit, checking and adjusting (B5XX4TX (2002-) and B5244S6)

Special tools

9995451

9995452

Note. The illustrations in this service information are used for different model years and/or models. Some variation may occur. However, the essential information in the illustrations is always correct.

Note. This procedure must be carried out with precision as any deviation could generate a fault symptom.

Aligning the crankshaft

Turn the crankshaft counter-clockwise until it stops against the adjustment tool.

Check that the marking on the crankshaft timing gear pulley corresponds to the marking on the oil pump.

Installing the variable valve timing unit on the camshaft

Note. Oil the center screw before installation

Push on the variable valve timing unit/timing gear pulley on the camshaft.

Install the center screw (1) which secures the variable valve timing unit to the camshaft. Tighten slightly.

Slacken off, but do not remove the screws (2) which secure the timing gear pulley to the variable valve timing unit.

Turn the timing gear pulley until the screws at the oval holes are in the center position. Tighten the screws (2) slightly.

Turn the variable valve timing unit clockwise to its limit position so that the unit is in its end position.

Position the upper timing cover

Undo the center screw and continue turning clockwise until the timing gear pulley marking aligns with the marking on the upper timing cover.

Tighten the center screw in the variable valve timing unit. Tighten. See: Summary of specific components and tightening torques .

Note. Variable valve timing units do not have return springs and are easily thrown out of position when the camshaft belt is installed. Check that the markings align.

Install the belt in the following order

1. the idler pulley
2. intake cam
3. exhaust cam
4. water pump
5. tension pulley.

Scheme 876

This adjustment is to be made with a cold engine.

A suitable temperature is approximately 20 °C/68 °F.

At a higher temperature, for example with a warm engine or a higher ambient temperature, the needle is further to the right.

The illustration shows the position of the indicator when aligning the timing belt tensioner at approximately 20 °C/68 °F.

Note. There are two different tensioners depending on model year.

Fix the belt tensioner center screw in position and turn the belt tensioner eccentric clockwise until the tensioner indicator passes the marked position and reaches the end position. Then turn the eccentric back so the indicator reaches the marked position shown in the illustration. Tighten the center screw. See Summary of specific components and tightening torques .

Check that the indicator is in the correct position.

Scheme 877

Slacken off the 3 x screws for the timing gear pulley slightly (applies to both timing gear pulleys).

Install the center plug in the variable valve timing unit. Tighten. See: Summary of specific components and tightening torques .

Hold the center plug at 25 Nm at the same time as tightening the 3 x screws on the camshaft timing gear pulley to: Summary of specific components and tightening torques .

Tighten the 3 x screws on the timing gear pulley for the intake camshaft. See: Summary of specific components and tightening torques . This is to ensure that the variable valve timing (VVT) unit is in its end position when the timing gear pulley is tightened.

Scheme 878

Remove

1. «9995452»(ref-403953-S02369714572011061000000) from the rear of the camshafts
2. «9995451»(ref-403953-S26663901482011061000000) . Install new plugs with new sealing washers. Tighten. See: «Summary of specific components and tightening torques»(ref-408601-S06859597342011071200000) .

Checking the markings and belt tension.

Position the upper timing cover.

Turn the crankshaft 2 rotations. Check that the markings on the crankshaft and timing gear pulleys correspond.

Remove the upper timing cover.

Variable valve timing unit, checking and adjusting (B6XX4T (2002-2006))

Special tools

9995451

Note. The illustrations in this service information are used for different model years and/or models. Some variation may occur. However, the essential information in the illustrations is always correct.

Scheme 879

Remove the starter motor mounting screws. Pull out the starter motor and put it aside.

Remove the blind cover plug for the adjustment tool hole. Turn the crankshaft clockwise slightly. Install the adjustment tool 9995451 . Ensure the adjustment tool bottoms against the engine block.

Turn the crankshaft counterclockwise to its stop against the crankshaft adjustment tool. Check that the marking on the crankshaft timing gear pulley aligns with the marking on the oil pump.

Scheme 880

1. Slacken off, but do not remove the screws which secure the timing gear pulley to the VVT unit
2. Press the variable valve timing unit and timing gear onto the camshaft
3. Install the center screw which secures the variable valve timing unit to the camshaft. Tighten slightly
4. Turn the variable valve timing unit counter-clockwise as far as it will go. Slacken off the center screw
5. Position the upper timing cover
6. Turn the timing gear pulley clockwise until the screws at the oval holes are in the limit position. Continue turning clockwise until the timing gear pulley marking is 1 cogs before the marking on the upper timing cover NOTE: Do not turn counter-clockwise during this procedure.
7. Check that the timing gear pulley is still in the limit position in the oval holes
8. Tighten the center screw in the VVT unit. See «Tightening torque»(ref-439007-S25936758512011120700000) . Check that the variable valve timing unit does not rotate when tightening
9. Install and tighten the center plug according to «Tightening torque»(ref-439007-S25936758512011120700000) .

Scheme 881

Turn the variable valve timing unit clockwise to the limit position. Turn the timing gear pulley so that the markings correspond.

Scheme 882

1. Slacken off, but do not remove the screws which secure the timing gear pulley to the VVT unit
2. Press the variable valve timing unit / timing gear onto the camshaft
3. Install the center screw which secures the variable valve timing unit to the camshaft. Tighten slightly
4. Turn the variable valve timing unit counter-clockwise as far as it will go
5. Slacken off the center screw
6. Turn the timing belt pulley clockwise until the screws at the oval holes are in the end-position. Continue turning clockwise until the timing belt pulley marking is 2 cogs before the marking on the upper timing casing. NOTE: Do not turn counter-clockwise during this procedure.
7. Check that the timing gear pulley is still in the limit position in the oval holes
8. Tighten the center screw in the VVT unit. See «Tightening torque»(ref-439007-S25936758512011120700000) . Check that the variable valve timing unit does not rotate when tightening
9. Install and tighten the center plug according to «Tightening torque»(ref-439007-S25936758512011120700000)

Turn the variable valve timing unit clockwise to the limit position. Turn the timing gear pulley so that the markings correspond.

Scheme 883

Tighten the timing belt tensioner center screw. Tighten to 5 Nm .

Install the belt in the following order

1. crankshaft
2. idler pulley
3. intake cam
4. exhaust cam
5. water pump
6. tension pulley

The variable valve timing units do not have a return spring and are easily dislodged when installing the timing belt. Check that the markings correspond.

Note. Adjust the timing gear pulleys so that the screws are not at the limit positions in any of the oval holes.

Scheme 884

This setting is done on a cold engine. A suitable temperature is approximately 20°C/68°F . At higher temperatures, for example if the engine is warm or ambient temperature is higher, the indicator assumes a position farther to the right. The illustration shows the indicator position at different engine temperatures.

Adjusting the timing belt

Hold the belt tensioner center screw fixed and turn the belt tensioner eccentric clockwise until the tensioner indicator passes the marked position.

Turn the eccentric back so that the indicator reaches the marked position in the center of the window. Remember to hold the center screw secure at the same time.

Hold the eccentric secure and tighten the center screw. Tighten to 25 Nm .

Check that the indicator is in the correct position.

Check

1. that the timing gear pulley is not in the limit position in the oval holes
2. the timing gear pulley so that the markings line up with the upper timing cover.

Tighten the screws for the timing gear pulleys. See Tightening torque

Checking the markings and belt tension

1. Jerk the camshaft belt to check that the indicator on the tensioner moves easily
2. Position the upper timing cover.
3. Turn the crankshaft two turns. Check that the markings on the crankshaft timing gear pulley and the camshaft timing gear pulley match up with the markings on the oil pump and upper timing cover respectively
4. Check that the indicator on the belt tensioner is within the marked position