BMW Coupes and Sedans 1970-1988 Repair Guide

Timing Chain (Front) Cover

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REMOVAL & INSTALLATION



1600, 2000, 2002, 318i and 320i Models

There are 2 timing chain covers, one upper and one lower, which must be removed to service the timing chain and sprocket assemblies.

  1. Remove the cylinder head cover. Disconnect the negative battery cable. Disconnect the air injection line at the front of the thermal reactor (if so equipped).
  2.  
  3. On the 318i, unfasten the bracket located on the driver's side of the upper cover.
  4.  
  5. Remove the bolts which retain the upper timing gear cover to the cylinder head and lower timing gear cover. remove the upper cover, taking note of the placement of the alternator ground wire.
  6.  
  7. Drain the cooling system and remove the radiator, preheater intake air assembly (carburetor equipped cars only) and radiator hoses as outlined in this section.
  8.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Bend back the lockplates for the fan retaining bolts. Remove the bolts and lift off the fan.
  2.  
  3. Loosen the alternator retaining bolts. Push the alternator toward the engine and remove the fan pulley and the alternator drive (fan) belt.
  4.  
  5. On 318i models, remove the alternator and tensioning bar. remove the 4 mounting bolts from the air pump bracket (where it attaches to the block), and remove the pump and bracket; then remove the bolt attaching the tensioning bar to the block and remove the tensioning bar.
  6.  
  7. Unfasten the coolant hoses from the water pump. Remove the 6 retaining bolts and copper sealing washers and lift off the water pump.
  8.  
  9. Unscrew the plug and remove the spring from the cam chain tensioner assembly, taking care to cushion the sudden release of spring tension. Remove the plunger (piston).
  10.  
  11. On 320i models, unfasten the multiple plug and cable lead from the alternator. Remove the alternator with its bearing block and clamping strap.
  12.  
  13. Remove the flywheel inspection plate and block the ring gear from turning with a small prybar.
  14.  
  15. Unscrew the crankshaft pulley nut and pull off the belt pulley.
  16.  
  17. Remove the bolts which retain the lower cover to the cylinder black and oil pan. On 318i models, remove the bolts retaining the brace plate and remove it. Also on the 318i, loosen the oil pan lower retaining bolts not directly involved with the lower cover. With a sharp knife, carefully separate the lower edge of the timing cover from the upper edge of the oil pan gasket at the front.
  18.  
  19. Remove the lower timing cover. At this time, it is advisable to replace the timing cover seal (sealing ring) with a new one. The sealing ring is a press fit into the cover.
  20.  

To install:
  1. Clean the mating surfaces of the timing covers, oil pan, cylinder head, and cylinder block. Replace all gaskets (except the oil pan gasket), and seal them at the corners with sealing compound such as Permatex® No. 2 or equivalent. If the oil pan gasket has been damaged, remove the oil pan and replace the gasket.
  2.  
  3. Reverse the above procedure to install, taking care to tighten the upper timing gear cover retaining bolts to 6-8 ft. lbs. (8-10 Nm). Note that on the 318i, the mounting web for the tensioning piston must be in the oil pocket. On 318i models, also make sure to pack the bores between the lower cover (at the top) and block with sealer.
  4.  

6-Cylinder Models
EXCEPT 524td, M3, M5 AND M6 MODELS

On 530i, 533, 535, 633/635 CS Series, and 700 Series engines, this procedure requires the use of a special gauge, to be made to a certain dimension.

  1. Remove the cylinder head cover. Remove the distributor. On all 3.2 liter models, detach the distributor guard and the air line going to the thermal reactor. On late model cars with Digital Motor Electronics (DME), follow this procedure to remove the distributor:
    1. Remove the distributor cap, which screws onto the cover directly in front of the camshaft.
    2.  
    3. Then, if the rotor is of the slide-on type, simply pull the rotor off and then remove the cover underneath it.
    4.  
    5. If the rotor is of the screw-on type, unscrew it from the distributor shaft, then unscrew the adapter underneath and, finally remove the cover underneath the adapter.
    6.  

  2.  
  3. Drain the coolant to below the level of the thermostat and remove the thermostat housing cover.
  4.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the bolts and remove the upper timing case cover with the worm drive which drives the distributor (pre DME cars only).
  2.  
  3. Remove the piston which tensions the timing chain, working carefully because of very high spring pressure.
  4.  
  5. Remove the cooling fan and all drive belts. On late model 600 Series cars, the alternator must be swung aside by loosing the front bolt and removing the 2 side bolts. On all cars with the 2.5L, 2.8L 3.0L and 3.2L engines, remove the attaching bolts and then remove the drive pulley from the water pump. The power steering pump must be removed, leaving the pump hoses connected and supporting the pump out of the way but so that the hoses are not stressed.
  6.  
  7. Remove the flywheel housing cover and lock the flywheel in position with an appropriate special tool.
  8.  
  9. Unscrew the nut from the center of the pulley and pull the pulley/vibration damper off the crankshaft.
  10.  
  11. Detach the TDC position transmitter on 600CS Series, 700 Series, and certain 528i models.
  12.  
  13. Loosen all the oil pan bolts, and then unscrew all the bolts from the lower timing case cover, noting their lengths for reinstallation in the same positions. Carefully use a knife to separate the gasket at the base of the lower timing cover. Then, remove the cover.
  14.  

To install:
  1. To install the lower cover, first coat the surfaces of the oil pan and block with sealer. Put it into position on the block, making sure the tensioning piston holding web (cast into the block) is in the oil pocket. Install all bolts; then tighten the lower front cover bolts evenly; finally, tighten the oil pan bolts evenly.
  2.  
  3. Inspect the hub of the vibration damper. If the hub is scored, install the radial seal so the sealing lip is in front of or to the rear of the scored area. Pack the seal with grease and install it with a sealer installer.
  4.  
  5. Install the pulley/damper and tighten the bolt to specifications. When installing, make sure the key and keyway are properly aligned.
  6.  
  7. Remove the flywheel locking tool and reinstall the cover. Reinstall and tension all belts.
  8.  
  9. Before installing the upper cover, use sealer to seal the joint between the back of the lower timing cover and block at the top. On some models, there are sealer wells which are to be filled with sealer. If these are present, fill them carefully. Check the cork seal at the distributor drive coupling, and replace it if necessary.
  10.  
  11. Just before installing the upper timing case cover, check the condition of that area of the head gasket. It will usually be in good condition. If it should show damage, it must be replaced.
  12.  
  13. If the car has the DME type distributor, inspect the sealing O-rings and replace as necessary. If it uses the DME distributor with the screw-off type rotor, make sure the bolt at the center of the rotor has its seal in place and that it is installed with a sealer designed to prevent the bolt from backing out.
  14.  
  15. Reverse the remaining portions of the removal procedures, making sure to bleed the cooling system.
  16.  

524td MODELS
  1. Disconnect the hoses and remove the air cleaner. Remove the belt driving the alternator and fan. Remove the attaching nuts and remove the fan, keeping it in the vertical position.
  2.  
  3. Remove the air hose running along the top edge of the cover. Remove the attaching bolts and remove the cover.
  4.  
  5. If removing the cover to replace the timing belt, proceed further to remove the vibration damper:
    1. Remove the remaining accessory drive belts.
    2.  
    3. Remove the belts and remove the fan drive pulley.
    4.  
    5. Remove the center bolt, and pull the pulley and vibration damper off the hub.
    6.  

  6.  
  7. Install in reverse order, tightening the center bolt for the vibration damper. Adjust belt tension.
  8.  

M3 MODELS
  1. Disconnect the negative battery cable. Drain the cooling system through the bottom of the radiator. Remove the radiator and fan.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Unfasten all electrical plugs, remove the attaching nuts, and remove the air cleaner and airflow sensor.
  2.  
  3. Note and if necessary mark the wiring connections. Then, unfasten all alternator wiring. Unbolt the alternator and remove it and the drive belt.
  4.  
  5. Unbolt the power steering pump. Remove the belt and then move the pump aside, supporting it out of the way but in a position where the hoses will not be stressed.
  6.  
  7. Remove the 3 bolts from the bottom of the bell housing and the 2 bolts below it which fasten the reinforcement plate in place.
  8.  
  9. Remove the drain plug and drain the oil from the lower oil pan. Then, remove the lower oil pan bolts and remove the lower pan.
  10.  


CAUTION
The EPA warns that prolonged contact with used engine oil may cause a number of skin disorders, including cancer! You should make every effort to minimize your exposure to used engine oil. Protective gloves should be worn when changing the oil. Wash your hands and any other exposed skin areas as soon as possible after exposure to used engine oil. Soap and water, or waterless hand cleaner should be used.

  1. Remove the 3 bolts fastening the bottom of the front cover to the front of the oil pan. Loosen all the remaining oil pan bolts so the pan may be shifted downward just slightly to separate the gasket surfaces.
  2.  
  3. Remove the water pump as described in this section. Remove the center bolt and use a puller to remove the crankshaft pulley.
  4.  
  5. Remove the piston for the timing chain tensioner.
  6.  
  7. Remove the 2 bolts attaching the top of the front cover to the cylinder head. Then, remove all the bolts fastening the cover to the block.
  8.  
  9. Run a knife carefully between the upper surface of the oil pan gasket and the lower surface of the front cover to separate them without tearing the gasket. If the gasket is damaged, remove the oil pan and replace it, as described in this section.
  10.  

To install:
  1. Before reinstalling the cover, use a file to break or file off flashing at the top rear of the casting on either side so the corner is smooth. Replace all gaskets, coating them with silicone sealer. Where gasket ends extend too far, trim them off. Apply sealer to the area where the oil pan gasket passes the front of the block.
  2.  
  3. Slide the cover straight on to avoid damaging the seal. Install all bolts in their proper positions. Coat the 3 bolts fastening the front cover to the upper oil pan with a sealer such as Loctite® 270® or equivalent. Tighten the bolts at the top, fastening the lower cover to the upper cover first. Then, tighten the remaining front cover bolts and, finally, the oil pan bolts to 7 ft. lbs. (9 Nm). If the car has the DME type distributor, inspect the sealing O-rings and replace as necessary. If it uses the DME distributor with the screw-off type rotor, make sure the bolt at the center of the rotor has its seal in place and that it is installed with a sealer designed to prevent the bolt from backing out.
  4.  
  5. Reverse the remaining portions of the removal procedures, making sure to fill and bleed the cooling system and to refill the oil pan with the correct oil. Tighten the oil drain plug to 24 ft. lbs. (31 Nm) and both upper and lower oil pan bolts to 7 ft. lbs. (9 Nm).
  6.  

M5 AND M6 MODELS
  1. Disconnect the battery ground cable. Pull out the plug and remove the wiring leading to the airflow sensor. Loosen the hose clamp and disconnect the air intake hose. Remove the mounting nut and remove the air cleaner and airflow sensor as an assembly.
  2.  
  3. Remove the radiator and fan. Remove the flywheel housing cover and install a lock to lock the position of the flywheel. Remove the mounting nut for the vibration damper with a deepwell socket. Pull the damper off with a puller.
  4.  
  5. Remove the pipe that runs across in front of the front cover. Remove the mounting bolts and remove the water pump pulley.
  6.  
  7. Loosen the top front mounting bolt for the alternator. Remove the lower front bolt. Loosen the 2 side bolts. Swing the alternator aside.
  8.  
  9. Remove the power steering pump mounting bolts. Make sure to retain the spacer that goes between the pump and oil pan. Swing the pump aside and support it so the hoses will not be under stress.
  10.  
  11. Remove the flywheel housing cover and lock the flywheel in position with an appropriate special tool.
  12.  
  13. Unscrew the nut from the center of the pulley and pull the pulley/vibration damper off the crankshaft.
  14.  
  15. Remove the bolts at the top, fastening the lower front cover to the upper front cover. Remove the bolts at the bottom, fastening the lower cover to the oil pan. Loosen the remaining oil pan mounting bolts.
  16.  
  17. Run a knife carefully between the upper surface of the oil pan gasket and the lower surface of the front cover to separate them without tearing the gasket.
  18.  
  19. Loosen and then remove the remaining front cover mounting bolts, noting the locations of the TDC sending unit on the upper right side of the engine and the suspension position sending unit on the upper left. Also, keep track of the bolts that mount these accessories, as their lengths are slightly different. If necessary, lay the bolts out in a clean area in a pattern similar to that in which they are positioned on the engine. Remove the timing cover, pulling it off squarely.
  20.  

To install:
  1. Before reinstalling the cover, use a file to break or file off flashing at the top rear of the casting on either side so the corner is smooth. Replace all gaskets, coating them with silicone sealer. Where gasket ends extend too far, trim them off. Apply sealer to the area where the oil pan gasket passes the front of the block.
  2.  
  3. Slide the cover straight on to avoid damaging the seal. Install all bolts in their proper positions. Tighten the bolts at the top, fastening the lower cover to the upper cover first. Then, tighten the remaining front cover bolts and, finally, the oil pan bolts. If the car has the DME type distributor, inspect the sealing O-rings and replace as necessary. If it uses the DME distributor with the screw-off type rotor, make sure the bolt at the center of the rotor has its seal in place and that it is installed with a sealer designed to prevent the bolt from backing out.
  4.  
  5. Reverse the remaining portions of the removal procedures, making sure to refill and bleed the cooling system.
  6.  

 
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