Intake Manifold Gasket Replacement Cost

Sealing the intake manifold to the engine's cylinder head is necessary for the engine to run properly. The intake manifold gasket may be rubber or paper, and fills the tiny gap between the intake manifold and the engine , eliminating the possibility of leaks.

The intake manifold is a distribution system for air, and sometimes fuel. As the throttle body opens, the engine intake stroke sucks in air through the intake manifold. The position of the throttle body will determine the amount of air that flows through. Vehicles that do not use direct injection will distribute fuel as well, but this system is becoming less common. Negative pressure, otherwise called a vacuum, is built-up inside the intake manifold, and the manifold gasket is used to prevent any un-metered air, air that did not pass through the mass airflow sensor, from entering the system.

Intake leaks cause many problems for combustion engines, so when the intake manifold gasket leaks, those problems are normally more apparent. Exhaust gas temperatures will rise from lean running conditions, the engine will have misfires, engine surging followed by loss of power is common, and fuel mileage is significantly impacted. Because many items, like the power brake booster, many engine control functions, some air conditioner functions, the evaporative emissions control system, and the engine all rely on engine vacuum to operate, these components may stop functioning properly. vehicles with metal intake manifolds may experience engine coolant or engine oil leaks, which can create white or sooty smoke from the exhaust pipe, and cross contamination between the engine cooling system and the engine oil system. If this occurs, there will be oil in the coolant reservoir, and coolant on the engine oil dipstick. Aside from these symptoms, the check engine will illuminate to inform you the vehicle is having problems. When the on-board diagnostic (OBD) trouble codes are read, they will likely reference the mass airflow sensor, throttle position sensor, manifold absolute pressure sensor, fuel delivery system, exhaust system, engine misfires, and intake air temperature. These codes will go to show how vital of the intake manifold gasket really is.

Erratic engine performance, power surging, possible oil and coolant leaks, and very poor gas mileage may result when driving a vehicle with a bad intake manifold gasket. Also, the vehicle may stall randomly, and may not restart. It is better to avoid these issue, and the wear and tear to the vehicle, by using a towing service instead of driving.

Intake manifolds are anticipated the life of the engine, but that is often not the case. Intake manifold gaskets, like most other types, fail much less frequently than they used to. This is because of superior manufacturing methods and engineering that we have today. Most vehicles will have the intake manifold gasket changed during their useful life, but that is normally due to other repairs requiring the removal of the intake manifold, or, for rubber intake manifold gaskets, the rubber becomes brittle and must be changed every several years. However, plastic intakes that use rubber intake manifold gaskets are mostly direct injection, and the manifold must be removed periodically to clean the intake valves and intake ports on the engine. When this service is performed, the intake manifold gasket is changed by recommendation from most manufacturers,

Any of the mentioned symptoms are going to point to the intake manifold at some point, and if failure has occurred, the technician will find it. The intake manifold gasket will be tested in an observable manner that will provide the technician with evidence that the intake manifold gasket is faulty. This may include introduction of a liquid or vapor being introduced to the intake manifold exterior while the engine is running, but this is not a preferred method. Generally, a smoke machine will be connected to the intake manifold with the engine off, and the pressure will push smoke out of leaks - including the intake gasket.

Most modern vehicles require the intake manifold to be removed to replace the fuel injectors, clean the intake ports, or, of course, replace the intake manifold gasket. This can be a large job that may involve draining the engine coolant and engine oil, removing many engine components, and replacement of the intake manifold gasket. 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. Once access is available, the fuel injector is disconnected from the fuel rail and electrical connector, and removed. Replacement is the reverse.

When replacing the intake manifold gasket, the fuel injectors may require removal, and using OEM replacement fuel injector seals is normally the best option. Also, there are many brands of intake manifold gaskets, and the most cost effective option may not be manufactured to meet or exceed OEM standard.

When removing an intake manifold, fuel injectors and fuel rails are normally disconnected or removed. When working with fuel, the battery should always be disconnected, and proper precautions taken against fire and inhalation hazards.

The intake manifold is not recommended to be removed and replaced unless a trained technician is completing the repair. This is not advised for the DIYer, and there are many ways to make an expensive mistake while replacing this gasket. This should be left to a professional technician.