Hydraulic Adjusting Elements, Checking
Special tools, testers and auxiliary items required
- Adapter T40058
- Feeler gauge
Note. The hydraulic adjusting elements cannot be repaired. Irregular valve noises are normal while starting the engine.
Procedure
- Start the engine and let it run until the radiator fan has switched on once.
- Increase engine speed for about 2 minutes to approximately 2500 RPM, perform road test if necessary.
Note. If irregular valve noises disappear but reappear during short drives, replace the oil check valve --> Oil Check Valve and Spray Nozzle Valve, Removing and Installing .
If the hydraulic adjusting elements are still loud, determine which element is faulty
- Remove cylinder head cover: Left --> «Left Cylinder Head Cover, Removing and Installing»(/audi/s8/d3-2007-2011/remont/cooling-fan/#52l-10-cyl-4v-engine-mechanical-engine-codes-bsm__left-cylinder-head-cover-removing-and) , right --> «Right Cylinder Head Cover, Removing and Installing»(/audi/s8/d3-2007-2011/remont/cooling-fan/#52l-10-cyl-4v-engine-mechanical-engine-codes-bsm__right-cylinder-head-cover-removing-and) .
- Remove fan shroud --> «Fan Shroud, Removing and Installing»(/audi/s8/d3-2007-2011/remont/cooling-fan/#52l-10-cyl-4v-engine-mechanical-engine-codes-bsm__fan-shroud-removing-and-installing) .
- Insert Socket T40058 adapter so that small diameter - arrow 2 - points to engine. Large diameter - arrow 1 - points to socket.
- Rotate crankshaft in direction of engine rotation - arrow - using adapter T40058 until camshafts on the hydraulic adjuster that needs to be checked face upward.
Scheme 266
- Determine play between camshaft and roller rocker lever by pressing lever down using a screwdriver - arrow -.
If a 0.20 mm feeler gauge can be inserted between camshaft and roller rocker lever
- Replace hydraulic adjusting element --> «Camshafts, Removing and Installing»(/audi/s8/d3-2007-2011/remont/cooling-fan/#52l-10-cyl-4v-engine-mechanical-engine-codes-bsm__camshafts-removing-and-installing) .
Final procedures
- Install fan shroud --> «Fan Shroud, Removing and Installing»(/audi/s8/d3-2007-2011/remont/cooling-fan/#52l-10-cyl-4v-engine-mechanical-engine-codes-bsm__fan-shroud-removing-and-installing) .
- Install cylinder head cover: Left --> «Left Cylinder Head Cover, Removing and Installing»(/audi/s8/d3-2007-2011/remont/cooling-fan/#52l-10-cyl-4v-engine-mechanical-engine-codes-bsm__left-cylinder-head-cover-removing-and) , right --> «Right Cylinder Head Cover, Removing and Installing»(/audi/s8/d3-2007-2011/remont/cooling-fan/#52l-10-cyl-4v-engine-mechanical-engine-codes-bsm__right-cylinder-head-cover-removing-and) .
Scheme 267
Note. Intake and exhaust valves must not be refaced by grinding. Only lapping is permitted.
| Dimension | Intake valve | Exhaust valve | |
|---|---|---|---|
| Diameter a | Mm | 33.85 ± 0.10 | 28.0 ± 0.1 |
| Diameter b | Mm | 5.980 ± 0.007 | 5.965 ± 0.007 |
| C | Mm | 103.97 ± 0.20 | 101.87 ± 0.20 |
| Α | Angle° | 45 | 45 |
| CAUTION | Worn sodium-filled exhaust valves must not be scrapped without first being properly treated. Using a metal saw, the valves must be cut into two pieces between the shaft center and valve head. While doing this, do not come into contact with water. At the very most, throw 10 of the prepared valves into a bucket filled with water. Then, move quickly away, because a sudden chemical reaction will occur during which the sodium is burnt away. The treated parts may then be discarded through conventional disposal channels. |