Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Valve gear
For engine S63 TOP, the fully variable valve stroke adjustment is used in addition to the double VANOS. The valve gear itself consists of known components. The rocker arms and intermediate levers made of shaped panels are new. More weight could thereby be saved in connection with the light construction camshaft. One tooth sleeve chain is used for each cylinder bank to drive the camshaft. Chain tensioner, tensioning rail and slide rails are common parts for both banks. The oil spray nozzles are integrated in the chain tensioner.
Valvetronic
The Valvetronic consists of the fully variable valve lift timing control and the variable camshaft timing control, which enables a free choice of closing time for the intake valve. Valve lift timing only takes place on the intake side; camshaft control takes placed on the intake and exhaust side. The opening time and closing time, and thereby the opening period and valve lift of the intake valve can thereby be selected freely.
The Valvetronic of the 3rd generation is already used in the engine N55.
Valve lift adjustment
As shown in the graphic below, the Valvetronic servomotor is installed on the intake side of the cylinder head. The eccentric shaft sensor is integrated in the Valvetronic servomotor.
| Index | Explanation |
|---|---|
| 1 | Exhaust camshaft |
| 2 | Intake camshaft |
| 3 | Gate |
| 4 | Intermediate lever |
| 5 | Spring |
| 6 | Valvetronic servomotor |
| 7 | Valve spring, intake side |
| 8 | VANOS, intake side |
| 9 | Intake valve |
| 10 | Exhaust valve |
| 11 | Valve spring, exhaust side |
| 12 | VANOS, exhaust side |
VANOS
The following differences apply to engine S63 compared to engine S63 TOP:
- The adjustment range of the VANOS was expanded by reducing from 4 to 5 wings. (Intake 70° crankshaft, exhaust 55° crankshaft)
- The weight could be reduced from 1050 g to 650 g by using aluminum instead of steel.
| Index | Explanation |
|---|---|
| 1 | Oil duct for early adjustment |
| 2 | Impeller |
| 3 | Oil duct for late adjustment |
| 4 | VANOS, exhaust side |
| 5 | VANOS, intake side |
| 6 | VANOS solenoid valve, inlet |
| 7 | VANOS solenoid valve, exhaust |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.