Exhaust Manifold: Service and Repair

WM 261019 Removing and installing exhaust manifold on 4.8-litre DFI engines

Technical values





Preliminary work

1. Remove engine. -> 100119 Removing and installing V8 4.8-litre DFI engine - section on "Removing" 100119 Removing and installing V8 4.8-litre DFI engine
2. Remove primary catalytic converter. For details, see -> 267619 Removing and installing primary catalytic converter on V8 4.8-litre DFI engines - section on "Removing" 267619 Removing and installing primary catalytic converter on 4.8-litre V8 DFI engines
3. Remove turbocharger. For details, see -> 213019 Removing and installing turbocharger on 4.8-litre DFI engines - section on "Removing" Service and Repair

Removing exhaust manifold

1. Spray fastening nuts on the exhaust manifold with anti-rust agent if necessary.
2. Loosen the fastening nuts on the exhaust manifold in reverse order to the sequence shown and remove them => Tightening sequence for exhaust manifold on turbo engine M48/51, cylinders 1 to 4. Remove exhaust manifold. Replace nuts.





Tightening sequence for exhaust manifold on turbo engine M48/51, cylinders 1 to 4

3. Remove and replace seal. Clean sealing faces. Cylinders 1 to 4 => Exhaust manifold on turbo engine M48/51, cylinders 1 to 4 , cylinders 5 to 8 => Exhaust manifold on turbo engine M48/51, cylinders 5 to 8.





Exhaust manifold on turbo engine M48/51, cylinders 1 to 4









Exhaust manifold on turbo engine M48/51, cylinders 5 to 8






Installing exhaust manifold

Information

- Visually inspect exhaust manifold for cracks and distortion.

- A cracked or distorted exhaust manifold must not be reinstalled.

- As a matter of principle, replace seals on manifold.

- Replace the studs in the cylinder head if damaged. Measure the studs with respect to the cylinder head and fit new studs to the same screw-in depth as the old studs.

1. Clean sealing surfaces. The surfaces must be free from foreign objects.
2. Use a new seal (the seal for the turbocharger is also replaced). The exhaust manifold seal must be positioned so that the part number is visible from the outside.
3. Slide the exhaust manifold over the studs and fit it using new fastening nuts. The fastening nuts are tightened in the specified tightening sequence as shown below. => Tightening sequence for exhaust manifold on turbo engine M48/51, cylinders 1 to 4 => Exhaust manifold on turbo engine M48/51, cylinders 1 to 4 => Exhaust manifold on turbo engine M48/51, cylinders 5 to 8





Tightening sequence for exhaust manifold on turbo engine M48/51, cylinders 1 to 4





Exhaust manifold on turbo engine M48/51, cylinders 1 to 4









Exhaust manifold on turbo engine M48/51, cylinders 5 to 8






Subsequent work

1. Fit turbocharger. -> 213019 Removing and installing turbocharger on 4.8-litre DFI engines - section on "Installing" Service and Repair
2. Install primary catalytic converter. For details, see -> 267619 Removing and installing primary catalytic converter on V8 4.8-litre DFI engines - section on "Installing" 267619 Removing and installing primary catalytic converter on 4.8-litre V8 DFI engines
3. Install engine. -> 100119 Removing and installing V8 4.8-litre DFI engine - section on "Installing" 100119 Removing and installing V8 4.8-litre DFI engine