Left Camshafts and Adjuster
Left Camshafts and Adjuster
• Installation of the camshaft drive chain to the left and right cylinder heads differ. Note the different procedures!
Special tools, testers and auxiliary items required
• Bracket for chain adjustment (3366)
• Retractor (3202)
• Sealant
Removing
• Engine is installed.
- Remove the toothed belt. Refer to => [ Toothed Belt ] Toothed Belt.
- Remove the camshaft gear.
- Loosen the nuts - 1 -.
- Remove the bolts - 2 - and remove the rear toothed belt guard.
- Disconnect the electrical connector - arrow - from the camshaft adjustment valve 2 (N208).
- Remove the left cylinder head cover. Refer to => [ Left Cylinder Head Cover ] Left Cylinder Head Cover.
- Disconnect the electrical connector - arrow - from the Camshaft Position (CMP) sensor 2 (G163).
- Remove the CMP sensor bolts and sensor.
- Remove the CMP sensor washer and cover.
- Rotate the crankshaft using the crankshaft toothed belt gear bolt counterclockwise approximately 45 degrees so that no pistons are at Top Dead Center (TDC).
- Verify the camshaft TDC position again:
• The two camshaft marks must align with the arrows on the bearing caps.
Reusing the Old Drive Chain
- Clean the drive chain and camshaft gears across from both arrows on the bearing caps and mark the installed position with a color mark.
• The distance between both arrows or colored marks consists of 15 rollers of the drive chain.
• Do not mark the chain using a center punch or similar means!
Continuation
- Secure the camshaft adjuster using the (3366).
• If the (3366) is fastened too tightly, the camshaft adjuster can be damaged.
- Independent of the existing markings on the bearing caps, mark the sequence and install position on all bearing caps, as shown in the illustration.
- For marking, clean the bearing cap and use a waterproof felt tip pen.
- Remove the bolts for the camshaft adjuster - 10 -.
- Remove the bearing cap 1.
- Remove the bearing caps 2, 4, 6, 8 and 9 and lay on a clean surface in the corresponding sequence.
- Alternating in a diagonal sequence, loosen the bearing caps 3, 5 and 7 on the intake and exhaust camshafts and remove.
- Raise both camshafts with the camshaft adjuster.
Installing
- Replace the bolts for camshaft bearing caps and camshaft adjuster.
- Replace the half round sealing plugs.
- Remove the sealant residue from the cylinder head and bearing caps.
- Replace the rubber/metal camshaft adjuster gasket and apply a thin bead of sealant on the hatched surface.
- Place the drive chain onto the camshaft gears as follows:
Using the Old Drive Chain
• Align the colored marks - arrows -.
Using a New Drive Chain
• Distance between notches - A and B - on the camshafts must be a distance of 15 rollers on the drive chain. Illustration shows where the first and fifteenth drive chain rollers must be installed on the gears.
Continuation
- Slide the camshaft adjuster between the drive chain (2nd technician needed).
- Install the camshafts with drive chain and camshaft adjuster on the cylinder head.
- Oil the running surfaces of both camshafts.
• Alignment sleeves for the bearing caps and camshaft adjuster must be installed in the cylinder head.
- Install bearing caps 3, 5, and 7 according to the marks.
- Tighten the bearing caps 3, 5 and 7 for the intake and exhaust camshafts in a alternating diagonal sequence.
- Install and tighten the bolts from the camshaft adjuster - 10 -.
- Remove the (3366).
- Check whether the camshafts are correctly adjusted:
• The two camshaft marks must align with both arrows on the bearing caps - arrows -.
• So that both marks line up, turn the camshaft slightly back or forth if necessary.
- Lightly apply sealant to the hatched surface of the double bearing cap as well as the outer bearing cap next to the camshaft adjuster and install the bearing cap.
- Install the remaining bearing caps.
- Replace the oil seals for the intake and exhaust camshafts. Refer to => [ Camshaft Seals ] Service and Repair or to => [ Camshaft Position Sensor Seal ] Service and Repair.
- Carefully drive in the cap using the (3202).
- Rotate the crankshaft using the crankshaft toothed belt gear bolt, clockwise approximately 45 degrees to TDC again and secure the crankshaft using the locking bolt.
Further installation is performed in reverse order of removal, noting the following:
- Install the toothed belt (adjust timing). Refer to => [ Toothed Belt ] Toothed Belt.
- Install the cylinder head cover. Refer to => [ Right Cylinder Head Cover ] Right Cylinder Head Cover.
- Install the torque support. Refer to => [ Torque Bracket and Support Valve Assembly Overview ] Torque Bracket and Support Valve Assembly Overview.
• After installing the camshafts, the engine may not be started for approximately 30 minutes. The hydraulic adjusting elements must seat themselves (otherwise the valves will seat themselves on the pistons).
• After working on the valvetrain, carefully rotate the engine by hand at least 2 full revolutions to ensure that valves do not strike the pistons when starting.
Tightening Specifications
• 1) Replace bolt
• 2) 90° corresponds to a quarter turn.
• 3) Insert using locking compound