Valve Clearance: Adjustments

Valve clearance

Note! Some variation in the illustrations may occur, but the essential information is always correct.

Special tools:
999 5454 PRESS TOOL 999 5454 Press Tool
999 5670 Pliers 999 5670 Pliers
999 5765 Holder camshaft 999 5765 Holder Camshaft
999 5752 Feeler gauge 999 5752 Feeler Gauge
951 2767 Roller 951 2767 Roller

Remove the variable valve timing unit. Refer to: VVT unit, B5254T7 VVT Unit

Removing the camshaft cover





Remove
- the variable valve timing (VVT) solenoid
- spark plugs for cylinders 1 and 5.
Install tool 999 5454 PRESS TOOL 999 5454 Press Tool (2 pcs.) with 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 Pliers 999 5670 Pliers 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 tappets. Mark up the tappets 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 air 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 tappet.
The sound made by tapping reveals if the valve is correctly seated.

Installing the camshaft and tappet





Install both the tappets for the inlet valves at cylinder 1.
Check the notes made earlier. Select new tappets if necessary.

Note! Only install two tappets. The tappets should be placed at the same cylinder!

Other tappets are available as replacement part / replacement part kits.
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 tappet to facilitate later measurement.

Installing the camshaft press





Install the lower section of camshaft press 999 5765 Holder camshaft 999 5765 Holder Camshaft by 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 must only be taken on a cold engine. Suitable temperature is approximately 20°C/68°F.

Use feeler gauge 999 5752 Feeler gauge 999 5752 Feeler Gauge.
Press with a finger so that the feeler gauge lies parallel to the upper side of the tappet (see illustration).
Move the feeler gauge sideways when taking the reading in order to obtain as accurate a measurement as possible.
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.

- 0.01 mm at 15 °C
+ 0.01 mm at 25 °C
+ 0.02 mm at 30 °C
+ 0.03 mm at 35 °C
+ 0.04 mm at 45 °C

Correcting measured clearance
Lift out the upper section of the press tool.
Lift out the camshaft.
Adjust the play by replacing the tappets.
Other tappets are available as replacement part / replacement part kits.
Reinstall the camshaft and the upper section of the press tool. Tighten to 12 Nm.
Make a new valve clearance measurement.

When the correct valve clearance is reached





Remove
- the press tool 999 5765
- the camshaft
- the tappets.

Note! Carefully mark the tappets so that exact reinstallation can be carried out.





Repeat the procedure for measuring the valve clearance for all cylinders on both the intake and exhaust sides.

Installing tappets and camshafts





Note! For tightening torques not in the text, see Specifications Tightening Torque.

Lubricate the valve guide wells.
Install all the tappets.
Lubricate the camshaft bearing seats and the upper sides of the tappets.
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.





Caution! Make sure that the mating faces are clean and free of foreign material.

Use liquid gasket, part number 1161059.
Ensure that no liquid gasket gets in to the oil galleries.
951 2767 Roller 951 2767 Roller




999 5454 PRESS TOOL 999 5454 Press Tool
Torque: M7, 17 Nm

Install the VVT unit. Refer to: VVT unit, B5254T7 VVT Unit