Checking Valve Clearance
Valve Mechanism
Checking valve clearance
NOTE: As 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.
Preparation
Remove, (turbocharged engines)
- the charge air pipe above the engine and holder at the rear of the engine
- the cover over the intake camshaft
- clamp the injectors cable harness.
Remove (common)
- the upper timing cover
- the cover over the ignition coils.
Remove (naturally aspirated engine)
- the inlet hose between the air cleaner (ACL) and throttle body (TB)
- the crankcase ventilation hose from the inlet hose. Place the inlet hose to one side
- the camshaft position (CMP) sensor housing. Place to one side
- the trigger wheel.
Remove (common)
- the ignition coils without removing the connectors.
NOTE: Mark up before removal.
- the two ground connections
- the connector for the variable valve timing solenoid
- the right front wheel
- the plastic nuts holding the cover for the fender liner.
Set the engine to the test position
Install tool 999 5754 at the rear of the intake camshaft.
Turn the crankshaft in the direction of engine rotation (clockwise) until the marking on the tool (In1/Ex4) is in opposite the thin flange running straight over the top of the entire cylinder head.
Remove all plugs from the test holes.
NOTE: If the crankshaft is turned to far, it is essential that it is turned back at least a quarter of a turn so that it can then be turned clockwise to the correct position.
Check the valve clearance
- Check the valve play with feeler gauge 999 5752 at cylinder. 1 intake valves and cylinder 4 exhaust valves.
- Insert the feeler gauge through the inspection holes. Bend the feeler gauge with light finger pressure so that it follows the top of the valve lifter.
- The correct measurement will not be obtained until the feeler gauge has gone in approximately 15 mm.
Reference values
Valve: Valve clearance:
Intake valve 0.15 - 0.45 mm
Exhaust valve 0.35 - 0.60 mm
CAUTION: This is only the check value.
NOTE: Carry out this check with the engine at room temperature.
Make a note of the valve clearance on a form.
Next test measurement
Turn the crankshaft in the direction of engine rotation until the next marking In2/Ex5 is opposite the flange on top of the cylinder head. Perform the test measurement according to the previous description.
Continue by measuring the remaining valve clearances according to the markings on tool 999 5754.
Finishing
Install (common)
- the plugs for the test holes. Tighten to 20 Nm
- the ignition coils according to the earlier markings
- the ground connections
- the connector for the variable valve timing solenoid.
Remove tool 999 5754.
Install (naturally aspirated engine)
- the trigger wheel. Tighten to 17 Nm.
NOTE: Ensure that the trigger wheel is correctly positioned against the camshaft.
- the camshaft position (CMP) sensor housing
- the cover over the ignition coils
- the upper timing cover
- the crankcase ventilation hose on the inlet hose
- the inlet hose between the air cleaner (ACL) and throttle body (TB)
- the plastic nuts from the cover in the fender liner
- the right front wheel.
Install (turbocharged engine)
- a new cover over the intake camshaft
- secure the cable harness for the injector
- charge air pipe above the engine and holder at the rear of the engine.
Install (common)
- the plastic nuts from the cover in the fender liner
- the right front wheel.
Valve clearance, setting/adjusting
Special Tools: 951 2767, 999 5450, 999 5451, 999 5452, 999 5454, 999 5670, 999 5718, 999 5719, 999 5752, 999 5765
NOTE: There are a number of versions of the variable valve timing unit. Therefore it is extremely important to always read the information referring to the engine variant/model year to be remedied.
Preparation
- Remove the cable from the battery negative terminal.
- Check the valve clearance.
NOTE: Make a note of the valve clearance in the inspection form.
Remove
- the cross stay between the suspension turrets
- the ground strip from the cylinder head
- the upper engine stabilizer brace
- the cover in the cylinder head at the rear of the exhaust camshaft
- the crankcase ventilation hose from the top of the camshaft cover
- the radiator breather tube from the expansion tank. Install lock grip pliers.
Lift up the brake fluid reservoir.
Disconnect the ABS sensor connector.
Place the brake fluid reservoir over the engine.
WARNING: Ensure that no fluid is spilled on the engine. It is extremely flammable.
Disconnect the connector for the level sensor in the expansion tank.
Lift up and place the expansion tank on top of the engine.
Remove
- the auxiliaries belt
- the front timing cover.
Position the upper timing cover.
Turn the crankshaft clockwise until the markings on the crankshaft belt pulley and the timing belt pulley are aligned with the markings on the oil pump and the upper timing cover.
Remove the upper timing cover.
CAUTION: Crankshaft and camshafts must not be turned more than is stated in the method description. If the shafts are turned in any other way the valves may be damaged.
Removing the timing belt
- Slacken off the center screw for the belt tensioner slightly.
- Hold the center screw still. Turn the tensioner eccentric clockwise to 10 O'clock using a 6 mm Allen key.
- Remove the timing belt from the camshaft pulleys.
Removing the timing gear pulley
- Install camshaft adjustment tool 999 5452 at the rear of the camshafts.
- Check that the screws securing the adjustment tool to the camshafts and the screw holding the tool together are well tightened
Remove (timing gear pulley with variable valve timing unit)
- the plug at the front of the variable valve timing unit (Tx55)
- the center screw in the variable valve timing unit (Tx55). Carefully pull out the variable valve timing unit with the timing gear pulley.
Remove (timing gear pulley without variable valve timing unit)
- the screws securing the timing gear pulley on the camshaft
- the timing gear pulley.
Remove tool 999 5452.
Reinstall the expansion tank and the brake fluid reservoir at the fender liner.
Removing the camshaft cover
- Remove
- the variable valve timing (VVT) solenoid
- spark plugs for cylinders 1 and 5.
- Install 2 tools 999 5454. Leave a 2 - 3 mm gap to the camshaft cover.
- Ensure that the screw in the spark plug well is fully tightened.
- Remove all the screws securing the camshaft cover to the cylinder head.
- Use pliers 999 5670 to lift the cover from the cylinder head.
- Install the pliers at the stop lugs. Start with cylinder 1 and work alternately backward.
- Slacken off the wing nuts approximately 2 turns. Repeat the procedure with the pliers.
- Carefully press the camshaft seals free.
NOTE: Take care not to damage the sealing surfaces on the camshafts.
- Remove
- tool 999 5454
- the camshaft cover
- the camshafts.
- Lift out the valve lifters. Mark up the valve lifters so that the original positions can be established.
Cleaning
Use a razor blade or a gasket scraper and gasket solvent P/N 1161 440 on the camshaft cover.
WARNING: Use a fume hood or extractor when using gasket solvent.
Use only a gasket scraper or razor blade on the cylinder head.
CAUTION: Take great care around the oil ducts for the variable valve timing solenoid. This applies to both the camshaft cover and the cylinder head. The solenoid is extremely sensitive to contaminants.
Dry and blow all surfaces clean.
Preparations
- Carefully tap the end of the valve stem to ensure that the valve is correctly located in the seat.
- Use a plastic, aluminum or brass drift to protect the valve and the surface of the valve lifter.
- The sound made by tapping reveals if the valve is correctly seated.
Installing the camshaft and valve lifter
- Install both the valve lifters for the inlet valves at cylinder 1.
- Check the notes made earlier. Select new valve lifters if necessary.
NOTE: Only install two valve lifters. The valve lifters should be placed at the same cylinder.
Other valve lifters are available as replacement part/replacement part kits.
The valve clearance on a cold engine (approximately 20 degree C) should be:
Inlet valve: 0.20 ± 0.03 mm.
Exhaust valve: 0.40 ± 0.03 mm.
NOTE: The tolerances are less at setting. When checking the valve clearance through the plug hole the tolerances are larger.
Position the intake camshaft. Ensure that the lobes at cylinder 1 point upwards.
Apply a little oil to the cam lobe and the upper side of the valve lifter to facilitate later measurement.
Installing the camshaft press
- Install the lower section of camshaft press 999 5765 at the inlet valves for cylinder 1.
- Tighten the tool against the cylinder head. Tighten to 17 Nm.
- Turn the camshaft until it stops against the camshaft press.
- Install the upper section of the camshaft press.
- Tighten the screw which tensions the camshaft. Tighten to 12 Nm.
Checking the valve clearance
NOTE: Measurements should only be taken on a cold engine. A suitable temperature is approximately 20 degree C.
Use feeler gauge 999 5752.
Press with a finger so that the feeler gauge lies parallel to the upper side of the valve lifter (see above figure).
Move the feeler gauge sideways when taking the reading in order to obtain as accurate a measurement as possible.
The valve clearance measured on cold engines (approximately 20 degree C) should be:
Inlet valve: 0.20 ± 0.03 mm.
Exhaust valve: 0.40 ± 0.03 mm.
NOTE: The tolerances are less at setting. When checking the valve clearance through the plug hole the tolerances are larger.
Differences in valve clearance for different engines/ambient temperatures:
- 0.01 mm at 15 degree C
+ 0.01 mm at 25 degree C
+ 0.02 mm at 30 degree C
+ 0.03 mm at 35 degree C
+ 0.04 mm at 45 degree C
Correcting measured clearance
- Lift out the upper section of the press tool.
- Lift out the camshaft.
- Adjust the play by replacing the valve lifters.
Other valve lifters are available as replacement part/replacement part kits.
Reinstall the camshaft and the upper section of the press tool. Tighten to 12 Nm.
Take a new measurement.
When the correct valve clearance is reached
Remove
- the press tool 999 5765
- the camshaft
- the valve lifters.
NOTE: Carefully mark the valve lifters so that exact reinstallation can be carried out.
Example:
Intake side: I1, I2, I3 I10.
Exhaust side: A1, A2, A3 A10.
Repeat the procedure for measuring the valve clearance for all cylinders on both the intake and exhaust sides.
Installing valve lifters and camshafts
- Lubricate the valve guide wells.
- Install all the valve lifters.
- Lubricate the camshaft bearing seats and the upper sides of the valve lifters.
- Position the intake camshaft. Ensure that the groove at the rear edge of the camshaft is above an imaginary center line.
- Position the exhaust camshaft. Ensure that the groove at the rear edge of the camshaft is below an imaginary center line.
Applying liquid gasket
- Wipe the oil film off the mating surfaces on the camshaft cover and cylinder head.
- Install new O-rings around the spark plug wells at the cylinder head.
- Apply liquid gasket 1161 059 on the camshaft cover. Use roller 951 2767.
NOTE: The surface must be completely covered without any excess.
CAUTION: Ensure that no liquid gasket gets in to the oil ducts.
Installing the camshaft covers
- Lubricate the camshaft lobes, the camshaft bearing surfaces and the valve lifters.
- Install the camshaft cover.
- Install press tool 999 5454 (2x).
- Tighten the camshaft cover screws alternately, keeping it parallel to the cylinder head using the press tools.
- Install all the screws. Tighten the screws from the middle and outwards.
- Remove the press tool 999 5454
Install
- the variable valve timing (VVT) solenoid. Use a new gasket
- the spark plugs. Tighten to 30 Nm
- the plugs for the test holes. Tighten to 20 Nm
- the crankcase ventilation hose to the top of the camshaft cover
- the ignition coils according to the earlier marking
- the ground terminals between the ignition coils.
Installing the rear camshaft seal
To clean the shaft journal and mating surface, use emery cloth P/N 951 1024.
NOTE: When cleaning work around the shaft journal, not in and out. It is essential that any residue from the emery cloth and any other contaminants are completely removed before the new sealing ring is installed.
Use drift 999 5450.
Lubricate the surface of the seal that the camshaft rotates against.
Press in the seal until the drift bottoms out.
NOTE: If there are wear grooves on the camshaft, the seal can be pressed in a further 2 mm by reversing the sleeve.
Install camshaft adjustment tool 999 5452 at the rear of the camshafts.
Check that the screws securing the adjustment tool to the camshafts and the screws holding the tool together are well tightened.
Installing the front camshaft seal
- Lift up and position the brake fluid reservoir and the expansion tank on top of the engine.
- Use drift 999 5718 on camshafts with variable valve timing units. Use drift 999 5719 on camshafts without variable valve timing.
- Use new seals and lubricate the surface of the seal that the camshaft rotates against.
- Use the variable valve timing unit/timing belt pulley mounting screws. Tighten the screws until the drift bottoms out.
- Remove the drift.
Fixing the crankshaft position
Remove
- the mounting screws for the starter motor. Pull off the starter motor. Place the starter motor to one side
- the blind cover plug and the seal washer.
Turn the crankshaft slightly clockwise.
Install the crankshaft stop 999 5451. Ensure that it bottoms out against the cylinder block.
Turn the crankshaft counter-clockwise until it stops against the crankshaft stop.
Check that the marking on the crankshaft timing gear pulley corresponds with the marking on the oil pump.
Installing the timing gear pulley for the camshafts
NOTE: The purpose of the procedure, "Installing the VVT unit/timing gear pulley", described here is to ensure that the VVT unit is correctly positioned and to reset the camshaft timing gear pulley to the correct position using the markings made at the factory. This is to ensure that the conditions are correct for any later fault-tracing.
Timing gear pulleys with variable valve timing units
- Slacken off, but do not remove the screws which secure the timing gear pulley to the variable valve timing unit.
- Press the variable valve timing unit/timing gear onto the camshaft.
- Install the center screw which secures the variable valve timing unit to the camshaft. Tighten slightly.
- Turn the variable valve timing unit counterclockwise as far as it will go.
- Remove the center screw.
- Position the upper timing cover.
- 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 tooth before the marking on the upper timing cover.
CAUTION: Do not turn counter clockwise during this procedure.
- Check that the timing gear pulley is still in its limit position at the oval holes.
- Tighten the center screw for the variable valve timing (VVT) unit. Tighten to 120 Nm. Check that the variable valve timing unit does not rotate when tightening.
- Install the center screw. Tighten to 35 Nm.
Timing gear pulleys without variable valve timing units
- Install the timing gear pulley. Install the screws.
- Install two screws without tightening. Allow the third screw to protrude.
- Adjust the timing gear pulleys so that the markings on the timing gear pulleys/upper timing cover correspond.
Installing the timing belt
- Tighten the center screw on the belt tensioner. Tighten to 5 Nm.
- Turn the variable valve timing unit clockwise to the stop.
- Hold it secure in the limit position.
Install the belt in the following order:
- crankshaft
- the idler pulley
- intake cam
- exhaust cam
- water pump
- belt tensioner.
NOTE: Adjust the timing gear pulleys so that the screws are not at a limit position in the oval holes. Also check that the markings correspond.
Tensioning the timing belt
- This adjustment is always carried out on a cold engine. A suitable temperature is approximately 20 degree C.
- At higher temperatures (with the engine at operating temperature or a high outside temperature for example) the indicator is further to the right.
- The above figure shows the position of the indicator when aligning the timing belt tensioner at different temperatures.
- Hold the center screw secure and turn the belt tensioner eccentric counter-clockwise until the tensioner indicator passes the marked position.
NOTE: Check that the variable valve timing unit is in its limit position.
- Tighten the three screws at the intake camshaft timing gear pulley. Tighten to 10 Nm.
- Tighten the three screws at the exhaust camshaft timing gear pulley. Tighten to 20 Nm.
- Turn the eccentric on the belt tensioner 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 20 Nm.
- Check that the indicator is in the correct position.
- Remove camshaft adjustment tool 999 5451 and crankshaft stop 999 5452.
- Install the plug with a new blind cover plug. Tighten to 40 Nm.
Checking the markings and belt tension
- Press the timing belt to check that the indicator on the tensioner moves easily.
- 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.
- Check that the indicator on the belt tensioner is within the marked position.
- Remove the upper timing cover.
Finishing
Install
- front timing cover
- the auxiliaries belt
- the servo oil reservoir
- the bleed hose for the expansion tank.
Close the clamp and check that the hoses lie correctly.
Connect the connectors for the
- The ABS sensor by the right suspension turret
- the coolant level sensor in the expansion tank.
Install
- the starter motor
- the plastic nuts for the cover in the fender liner
- the right front wheel.
- the trigger wheel.
NOTE: Ensure that the trigger wheel is correctly positioned against the camshaft.
- the camshaft position (CMP) sensor housing
- the cover at the rear of the exhaust camshaft
- the screws holding both the ground strips from the firewall to the cylinder head
- the upper engine stabilizer brace
- the cover over the ignition coils
- the upper timing cover
- the crankcase ventilation hose on the inlet hose
- the inlet hose between the air cleaner (ACL) and throttle body (TB)
- the engine stabilizer brace between the suspension turrets. Secure the servo hose at the right mounting for the engine stabilizer brace in the bodywork
- the cable to the battery negative terminal.
Check
Check the level in the expansion tank and the brake fluid reservoir.
Test drive the engine until the thermostat opens and check for any leakage.