Timing Chain Tensioner: Service and Repair

Camshafts and hydraulic chain tensioner, removing and installing

^ Cylinder head installed
^ Lock carrier in service position, Refer to, Radiator Support, Service and Repair.

Special tools and equipment
^ 3036 retainer
^ 3366 bracket-tensioner

Removing
^ Remove ribbed belt and ribbed belt tensioner.
^ Remove engine covers.
^ Remove upper toothed belt cover.





^ Turn crankshaft at central bolt of toothed belt gear in direction of engine rotation to TDC Cyl. 1 marking (arrows).
^ Remove cylinder head cover.

CAUTION! Before removing toothed belt, note direction of rotation with chalk or felt-tip marker. Reversing the direction of rotation of a used belt can destroy the belt





^ Loosen tensioner (arrows) and remove toothed belt from camshaft gear.
^ Use 3036 retainer to loosen camshaft gear.
^ Remove camshaft gear.
^ Remove housing for Camshaft
^ Position (CMP) sensor -G40-.
^ Remove shutter wheel for Camshaft
^ Position (CMP) sensor -G40-.





^ Secure hydraulic chain tensioner using 3366 bracket-tensioner.

CAUTION! If over-tightened, the chain tensioner will be damaged.

^ Verify that camshafts are at TDC Cyl 1.





Both camshaft markings must align with arrows on bearing caps.
^ Clean drive chain and camshaft chain gears opposite both arrows on bearing caps. Mark installed position using paint.





- The distance between the two arrows/paint marks is equivalent to 16 drive chain rollers.
- The notch on the exhaust camshaft is slightly offset inward toward drive chain roller (arrow-1-).

Note: Do not mark chain using punch, filing a notch or similar procedures.





^ First remove bearing caps -3- and -5- from intake and exhaust camshafts.
^ Remove double bearing cap.
^ Remove both bearing caps from chain gears on intake and exhaust camshafts.
^ Remove hydraulic chain tensioner retaining bolts.
^ Alternating in diagonal sequence, loosen bearing caps -2- and -4- of intake and exhaust camshafts and remove.
^ Remove intake and exhaust camshafts with hydraulic chain tensioner.

Installing





^ Replace rubber/metal chain tensioner gasket and spread sealant D 454 300 A2 on hatched surface.

CAUTION! Part numbers are listed here for reference only. Always check with your Parts department for the latest information.

Install drive chain on camshaft chain gear as follows:





^ When installing old drive chain, line up paint markings (arrows).





- If a new drive chain is installed, distance between notches -A- and -B- on camshafts must equal the distance between 16 drive chain rollers. Illustration shows where first and sixteenth drive chain rollers must be installed on chain gears.
- Notch -A- is slightly offset inward toward drive chain roller -1-.

^ Slide in hydraulic chain tensioner between drive chain.
^ Install camshafts with drive chain and hydraulic chain tensioner into cylinder head.
^ Oil camshaft contact surfaces.

Note:
^ Alignment bushings for bearing caps and hydraulic chain tensioner must be installed in cylinder head.
^ When installing bearing caps, verify marking on cap is readable from intake side of cylinder head.

^ Tighten hydraulic chain tensioner (pay attention to alignment bushings).





^ Tighten bearing caps -2- and -4- of intake and exhaust camshafts in alternating diagonal sequence (pay attention to alignment bushings).
^ Install both bearing caps on chain sprockets of intake and exhaust camshafts.
^ Verify correct position of both camshafts.





- Both camshaft markings must align with arrows on bearing caps (arrows).





- The distance between the two arrows/paint markings is equivalent to 16 drive chain rollers.
- The notch on exhaust camshaft is slightly offset inward toward drive chain roller -1-.

^ Remove 3366 bracket-tensioner.





^ Lightly coat hatched surface of double bearing cap with sealant D 454 300 A2 and install bearing cap (pay attention to alignment bushings).

CAUTION! Part numbers are listed here for reference only. Always check with your Parts department for the latest information.

^ Install remaining bearing caps (pay attention to alignment bushings).
^ Replace oil seals for intake and exhaust camshafts.





^ Install camshaft gear.
^ Note position: thin rib of camshaft gear points outward (arrows) and TDC Cyl. 1 marking is visible from the front.
^ Using 3036 retainer, install camshaft gear retaining bolt.
^ Install Camshaft Position (CMP) sensor G 40.
^ Install cylinder head cover.





^ Align marking on camshaft gear with marking on cylinder head cover.
^ Align marking on vibration damper with marking on lower toothed belt cover.

Note: When turning camshaft, crankshaft must not be at TDC Cyl. I for any cylinder. Valves and/or pistons may be damaged.

^ Install toothed belt (adjust valve timing), Refer to Timing Belt, Service and Repair.

Note: Follow all procedures for removing and installing toothed belt, Refer to Timing Belt, Service and Repair.

CAUTION!
^ After installing the camshafts, the engine must not be started for approximately 30 minutes. The hydraulic valve lifters have to settle (otherwise valves will strike the pistons).
^ After installing the valvetrain and lifters, carefully rotate the crankshaft by hand at least 2 full revolutions before starting to be sure that valves do not strike the pistons.

^ Install ribbed belt and ribbed belt tensioner.

Note: When installing ribbed belt, make sure it is seated correctly on the pulleys.








Tightening torques