Camshaft: Testing and Inspection

Checking Camshaft Timing

Remove fan impeller with fan clutch.
Remove cylinder head cover. Service and Repair
Remove all spark plugs. Service and Repair







Detach cover for inlet camshaft.





Caution: Cylinder for chain tensioning piston is under spring pressure.

Remove cylinder for chain tensioning piston.





Install special tool 11 4 220.
Fit adjusting screw to bow cover.





Preload tensioning rail with special tool 11 4 220 by rotating adjusting screw with special tool 00 9 250 or standard torque wrench to 0.7 Nm.





Unscrew oil pressure pipe.





Mount special tool 11 3 450 with banjo bolt of oil pressure line.

Caution: Cover double VANOS adjustment unit; when the compressed air supply is connected, several drops of oil are sprayed out of the bore.





Connect compressed air (2 to 8 bar).





Note:
When the engine is switched off, it is possible that the camshafts are not in their initial positions.
With the compressed air supply connected, rotate the engine to return the camshafts to their initial positions.

With compressed air supply connected, crank engine at least two revolutions in direction of rotation until cam tips on inlet and exhaust camshafts on 1st cylinder face each other.





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.





Unscrew studs.





Place special tool 11 3 240 on camshafts.





Note: In spite of correctly set camshafts, special tool 11 3 240 may protrude by up to 1 mm over inlet side.

Reason:
^ Rubberized chain wheel
^ Tolerances in VANOS adjustment unit
^ Running clearance in splines
If special tool 11 3 240 protrudes above the exhaust side, it will be necessary to readjust the timing.
If necessary, adjust camshaft timing, refer to Adjustments.





Detach compressed air connection.
Remove special tool 11 3 450.





Fit oil pressure line with new seals.
Tightening torque, refer to Specifications, Mechanical.





Remove special tool 11 3 240.





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.
Assemble engine.