If the above symptoms are present, the technician can test the intake manifold gasket by connecting a smoke machine to the manifold with the engine off. The pressure will push smoke out of any leaking parts, including the intake gasket.
How is a intake manifold gasket replaced?
Typically, the intake manifold will have to be removed to replace the gasket. This can be a large job that may involve draining the engine of coolant and oil and removing many engine components.
Many vehicles, however, are designed with plastic intake manifolds that do not have oil passages or coolant passages, and are much faster and more cost effective to remove and reinstall.
RepairPal recommendations for intake manifold gasket issues
When replacing the intake manifold gasket, the fuel injectors may require removal, and using OEM replacement fuel injector seals is the best option. When working with fuel, the battery should always be disconnected, and proper precautions should be taken against fire and inhalation hazards.