Removing toothed belt from camshafts, engine code CHPA, CZDA

Camshaft clamp -T10494-

Release tool -T10527-

Release tool -T10527/1-

Procedure

• Loosen hose clips -1, 2- and remove air pipe.

• Move air hoses clear at air pipe.
• Detach connector from charge pressure sender -GX26-.

• Release fasteners -arrows- using release tools -T10527- and -T10527/1-.
• Remove air pipe -1-.

• Press release buttons and pull off hose -1-.
• Remove bolts -arrows- and detach crankcase breather hose.
• Remove noise insulation → General body repairs, exterior; Rep. gr.66.
• Drain coolant → Chapter.

• Unscrew bolts -A ... D-, and push cover -1- for thermostat to one side.

• Lay wiring harness to one side -arrows-.
• Unscrew bolts -1, 3- and remove cover -2- for toothed belt for coolant pump.

• Unscrew bolts -arrows- and detach sealing cap -1-.
• Separate plug-in connectors from fuel hose and from hose to activated charcoal filter → Rep. gr.20.
• Release hoses from retainer -3- and lay them to one side.

• Remove bolt -2-.
• Release clips -arrows- and detach upper toothed belt guard -1-.

Note

• Unscrew bolts -arrows- and remove cover from camshaft adjuster for exhaust camshaft.

Rotate crankshaft to “TDC” as follows:

• Remove ignition coil 1 with output stage -N70- and cylinder 1 spark plug → Chapter.
• Insert a screwdriver with a shaft length of at least 250 mm into spark plug hole so that it contact piston crown.
• Turn the crankshaft in the normal direction of rotation until the piston in cylinder 1 shows “BDC”.

The screwdriver moves in the -direction of the arrow-.

• Turn the crankshaft further, until the screwdriver has moved -30 mm- in the -direction of the arrows-

• Unscrew plug for “TDC” hole in cylinder block.
• Screw locking pin -T10340- into cylinder block as far as stop and tighten to 30 N·m.
• Rotate crankshaft in normal direction of rotation as far as stop.

The locking pin now rests against the crank web.

Locking pin -T10340- locks crankshaft in direction of engine rotation only.

Risk of damage to engine

In this case, proceed as follows:

Unscrew locking pin.

Turn crankshaft 90° in direction of engine rotation.

Turn crankshaft in direction of engine rotation as far as stop.

• If camshafts are not positioned as described, unscrew locking pin -T10340-, turn crankshaft one rotation further and return to “TDC” position.

The camshaft clamp -T10494- must slide into position easily.

Do not knock camshaft clamp into place with any kind of tool.

If the camshaft clamp -T10494- does not easily slide into position:

• Use assembly tool -T10487- to push against toothed belt in -direction of arrow-.

• Insert camshaft clamp -T10494- as far as stop into camshaft.
• Tighten bolt -arrow- by hand.

• Unscrew plug -1- on camshaft sprocket on intake side using counterhold -T10172- with adapter -T10172/1-.

• Loosen bolts -1, 2- approx. 1 turn using counterhold -T10172- with adapter -T10172/1-.

• Loosen bolt -1- with tool insert -T10500-.
• Release tensioning roller on eccentric adjuster -2- using special wrench, 30 mm -T10499-.

Risk of damage to engine

Risk of damage to the toothed belt.

The toothed belt is made of glass fibre fabric.

Otherwise the service life of the toothed belt will be reduced.

• Remove toothed belt from camshaft pulleys.

Installing (adjusting valve timing)

Renew bolts that are tightened with specified tightening angle.

Renew O-ring of plug if damaged.

• Check “TDC” position of camshaft and crankshaft:

Camshaft clamp -T10494- must be attached to camshaft housing.

• Renew bolts -1- and -2- for camshaft pulleys and screw them in loosely.

Risk of damage to engine

Risk of damage to the toothed belt.

The toothed belt is made of glass fibre fabric.

Otherwise the service life of the toothed belt will be reduced.

Fit toothed belt in prescribed sequence:

• Pull toothed belt upwards and fit it on idler pulley -1-, tensioning roller -2- and camshaft toothed belt pulleys-3- and -4-.

• Using special wrench, 30 mm -T10499-, turn eccentric adjuster -2- of tensioning roller in direction of -arrow- until adjustment indicator -3- is positioned approx. 10 mm to the right of adjustment window.
• Turn eccentric adjuster back until adjustment indicator is positioned exactly in adjustment window.

Note

Torque wrench -VAS 6583- must be used for tightening.

• Hold eccentric in that position and tighten bolt -1- to 25 N·m using insert tool -T10500- with torque wrench -VAS 6583-.

• Tighten bolts -1, 2- initially to 50 N·m using counterhold -T10172- with adapter -T10172/1-.

• Unscrew locking pin -T10340-.

• Remove bolt -arrow- and detach camshaft clamp -T10494-.

Checking valve timing:

• Turn crankshaft 2 turns in direction of rotation of engine.
• Screw locking pin -T10340- into cylinder block as far as stop and tighten to 30 N·m.
• Rotate crankshaft further in direction of engine rotation as far as stop.

The locking pin now rests against the crank web.

Note

Locking pin -T10340- locks crankshaft in direction of engine rotation only.

• It should be possible to insert the camshaft clamp -T10494- easily.

Do not knock camshaft clamp into place with any kind of tool.

If the camshaft clamp -T10494- does not easily slide into position:

• Use assembly tool -T10487- to push against toothed belt in -direction of arrow-.

• While doing this, insert camshaft clamp -T10494- into camshafts as far as stop and hand-tighten with bolt -arrow-.

• Repeat adjustment of valve timing.

• Unscrew locking pin -T10340-.

• Remove bolt -arrow- and detach camshaft clamp -T10494-.
• Tighten bolts -1- and -2- to final torque setting → Chapter.

• Use counterhold -T10172- with adapter -T10172/1-.

• Tighten plug -1- using counterhold -T10172- with adapter -T10172/1-.

Risk of damage to engine

Further assembly is carried out in the reverse order of removal.

Specified torques

→ Chapter „Assembly overview - toothed belt“

→ Fig. „“Plug for TDC drilling in cylinder block - specified torque”“

→ Chapter „Assembly overview - crankcase breather system“

→ Chapter „Assembly overview - coolant pump, thermostat“

→ Chapter „Assembly overview - charge air system“