Chain tensioner — removal and installation (BMW 7 Series E32)

If the timing chain is noisy, remove and check the chain tensioner, which is installed on the right side of the engine. The timing chain is tensioned by a spring and oil pressure in the tensioner, which directly depends on the oil pressure in the engine.

Extraneous sounds from the chain may have the following causes:

• Poor plunger purging.
• Worn plunger. Clogged blow-off slot (ventilation gap).
• The ball valve is faulty.
• Spring stiffness too low or too high.

Removal

Loosen the plunger lock bolt.

Caution: The bolt is under strong spring pressure.

Remove the chain tensioner spring and plunger.

Examination

Measure the length of the spring in its free state. It should be 155.5 mm.

To make sure the ball (H) moves freely, shake the plunger (K).

Check the operation of the valve. To do this, blow compressed air into the plunger from the side indicated in the figure by number 1, and the valve should open. When blowing air in direction 2, the valve should close.

If not, knock the valve (F) out of the bushing (G) and clean it. Make sure that the purge slot (1) is clean.

Installation

Pour about 100 cm of oil into the hole in the engine cylinder block using an oiler



Install the plunger with spring and new sealing ring and tighten the locking bolt by hand.

Note: The conical end of the spring must face the bolt.

After unscrewing the mounting bolts, remove the cylinder head cover and the camshaft gear cover.

Move the tensioner in both directions until oil appears at the locking bolt and resistance to movement is felt.

Tighten the lock bolt to 35 Nm.

Secure the cylinder head cover and camshaft gear cover.