Can Cause Serious Problems Intake manifold leaks can lead to serious engine problems which result in repairs far more costly than replacing an intake manifold gasket. Some intake manifold leaks cause changes in vacuum pressure.
Abnormal combustion is the most common cause of damage to the head gasket.
It can even result in damage to hard parts such as pistons and spark plugs. Some intake manifold leaks can lead to external coolant leakage. Or, coolant might leak into the engine's oil supply, causing serious and expensive damage. If an exhaust crossover port passes through the intake manifold gasket, some leaks may result in a noisy engine, power loss or even a blown gasket. And, of course, leaks such as these can occur in combinations.