Camshaft: Testing and Inspection

Checking Camshaft Timing:

Removing fan wheel with fan coupling, refer to Cooling System, Fan Clutch, Service and Repair.
Removing cylinder head cover, refer to Cylinder Head Assembly, Valve Cover, Service and Repair.
Removing spark plugs, refer to Powertrain Management, Ignition System, Spark Plug, Service and Repair.





Pull off plastic cover for intake camshaft.





Rotate engine engine-wise until cam tips on intake and exhaust camshafts on 1st cylinder face one another.





Pull dust guard out of the special tool bore.





Secure crankshaft with special tool 11 2 300 in TDC firing position of 1st cylinder.

Caution: Do not turn the engine back. Remove special tool 11 2 300 before starting engine.





Caution: Strong spring force. Unfasten cylinder for chain tensioning piston.





Install special tool 11 4 220. Fit adjusting screw to tensioning rail.





Tighten tensioning rail with special tool 11 4 220 by rotating the adjusting screw with special tool 00 9 250 or preload with standard torque wrench to 1.3 Nm.





Unscrew studs.





Fit special tool 11 3 240 on 6th cylinder to camshaft and check the camshaft setting.
The camshaft setting is OK if special tool 11 3 240 locates flush against the cylinder head.
Remove special tool 11 3 240.

If necessary, check adjustment travel of VANOS adjustment unit and adjust timing of camshaft, refer to Adjustments.





Remove special tool 11 2 300. Install dust guard from inspection bore.





Relieve tension on special tool 11 4 220 and remove.





Install cylinder for chain tensioning piston:
M52
Refer to Engine, Timing Components, Timing Chain Tensioner. Service and Repair.
S52
Refer to Engine, Timing Components, Timing Chain Tensioner. Service and Repair.
Assemble engine.