Genuine 1991 Audi 100 Intake Manifold

1991 Audi 100 Intake Manifold Parts and Q&A

• Q: What precautions should be observed before working on the Intake Manifold components for single-point petrol injection on 1991 Audi 100?

  A: Note the precautions to be taken before handling the components of the fuel system. This will be done by removing the battery negative lead and emptying the engine of coolant. Take out throttle body and intermediate flange in the intake manifold and retrieve the gasket. Unscrew the clips and detach the coolant hoses with the intake manifold. De-attach the brake servo vacuum hose of the intake manifold. Unscrew the nuts and take out the warm air shroud in the exhaust manifold, should it be necessary. Unscrew the bolts and nut to detach the support bracket of the intake manifold, and pay attention to the fact that one of the bolts clamps the exhaust manifold CO sampling pipe support and spacer sleeve on the center stud. Disassemble the wiring and the intake manifold preheater connection at the connector. Gradually loosen the mounting bolts and nuts and then remove the intake manifold out of the cylinder head recovering the manifold gasket and the seal to the cooling system aperture. In case of need, take out the retaining screws and pull out the manifold preheater piece and recover the gasket and O-ring. To refit, the mating surfaces of the manifold and the heater unit should be clean and dry, a new gasket and O-ring should be installed and the mounting bolts securely tightened to the recommended torque. Make sure that the manifold and cylinder head mating surfaces are clean and dry, re-fit the intake manifold with a new gasket and cooling aperture seal, and retighten the retaining bolts and nuts to the required torque value. Restart all the other hoses to their proper places, fasten them with their retaining clips where applicable and reattach the throttle body. Lastly, fill up and bleed the cooling system.