The intake manifold is the bridge between the throttle body and engine cylinders. It is an integral part of the engine compartment that supplies the air and fuel mixture to the cylinders for combustion and continues the ignition procedure. The main function of the intake manifold in the Ford F150 is to distribute the air and fuel evenly in each cylinder for good engine performance.
Ford F150 intake manifold problems include broken air flaps, vacuum leaks, cracking and breaking of the intake manifold, worn-out gaskets, poor fuel economy, and carbon build-up on its surfaces.
I was driving my pickup truck last night and suddenly saw the check engine light on the instrumental cluster.
I stopped driving to inspect the engine parts because it was not safe to continue driving with the warning sign. I opened the hood and saw the milky appearance of the engine oil, representing coolant leakage because of the intake manifold cracking. I used the epoxy material to seal the cracked surface.
| Problems | Solutions |
| Broken air flaps | Replace the intake manifold runner valve |
| Vacuum leaks | Use the scanner tool to find error codes |
| Cracking and breaking of the intake manifold | Use epoxy for sealing |
| Worn out gaskets | Replace gaskets |
| Poor fuel economy | Replace intake manifold |
| Carbon builds up | Use additives to remove carbon |
Broken air flaps
Ford F150 intake manifolds are attached to the throttle body to supply air to the combustion chamber. In addition, it is also responsible for the even distribution of air in each engine cylinder for efficient engine performance and to reduce stalling issues.
Intake manifold runner valves open these flaps and allow the air to enter through them. The throttle valve adjusts the amount of air going through these flaps to control the engine rotations per minute.
Sometimes, these flaps break and do not allow the smooth flow of air inside the combustion chamber. Incorrect air flow also affects the fuel economy.
More fuel moves to the combustion chamber for air and fuel mixture burning. In addition, the air flaps break because of their age and continuous functioning.
These air flaps function continuously and are more vulnerable to age-related wear and tear. It is mounted on its head with screws.
These screws become loose and do not allow them to open and close properly according to the response of the throttle position sensor.
The issue also comes because of the corroded screws of the air flaps. Sometimes, the runner valves that control their opening and closing become bad and affect the idling speed.
These valves become bad because of age, overheating, and electric issues. Replacing the damaged valve with a new one is necessary to ensure smooth airflow inside the combustion chamber.
Furthermore, overheating also causes the warping of the valve, and they stick at a certain location. You cannot repair these valves because of their delicate system.
It is better to replace the intake manifold runner valve with a new one. You should also maintain it properly to decrease its sticking chances.
Vacuum leaks
Vacuum is created in the intake manifold through pistons and gaskets.
The air pressure difference and vacuum in these components create the suction effect to draw air. The engine draws air inside the combustion chamber through the suction and vacuum effect.
Vacuum leaks are common in Ford F150 engine components, affecting the truck’s performance. Plastic gasket seals are helpful to maintain the air pressure inside this part.
The vacuum leak issue comes because of the wear and tear of the gasket seals. These are vulnerable to wear and tear because of their age.
In addition, using low-quality and contaminated oil for engine parts lubrication also causes the degradation of plastic seals. These can also come off from these components because of their incorrect size.
Overheating from the engine compartment causes warping of the seals and vacuum leaks. My uncle also faced idling issues because of broken gasket seals.
He complained that he tried to start the truck last weekend, but it was consuming more fuel than usual, and he also faced difficulty starting it.
He used the scanner devices to find the error codes and resolve the issue. He saw the P0171 and P0174 codes on these scanner tools, which are the significant representers of the intake manifold vacuum leaks. He told me he went to the dealership to fix the vacuum leaks.
Cracking and breaking of the intake manifold
Ford F150 contains plastic intake manifold because these are more affordable than their metallic counterparts. However, these have less durability because of their delicate material, which is not resistant to high temperatures and certain impurities.
These are vulnerable to cracking because of the high temperature of the engine compartments. Engine temperature usually increases during long trips when you continuously drive the truck without any break.
In addition, these can also break because of the overtightening of their fasteners. Furthermore, poor handling and maintenance increase their cracking chances.
Certain vibrations from the roads and broken engine mounts increase the chances of cracking vacuum hoses or intake manifold lines. Engine backfiring is a significant contributor to the breaking of these lines.
Because of their cracking, you can see symptoms including rough idling, hard starting, and high fuel consumption. You do not have to replace this part if the crack is a hairline.
Hairline cracks do not lead to engine failure, and you can fix them with sealants. Use epoxy and other high-grade sealants to fix the hairline cracks permanently.
However, you have to use the welding procedure for the aluminum intake manifold because seals cannot work on the metal parts.
Worn out gaskets
Intake manifolds have plastic or metal gaskets to create the vacuum and maintain the air pressure for the suction effect. Sometimes, these gaskets wear out because of the overheating.
The high engine compartment temperature makes plastic gaskets vulnerable to shrinking and warping. Moreover, they can also crack because of their overtightening and incorrect installation.
Metal gaskets are prone to wear and tear because of their age. They become brittle because of long-term exposure to high temperatures.
Brittle metal cracks easily and causes vacuum leaks and engine issues. In addition, coolant leakage increases the risk of corrosion on metal gaskets and leads to their failure.
Moreover, the aluminum cylinder heads expand and contract according to temperature changes. Expansion of the aluminum head causes the cracking of plastic gaskets.
Inspecting these gaskets and replacing the worn-out ones with new ones is better. Install the metal gaskets because they can withstand high temperatures and are less vulnerable to cracking.
Use the gaskets of the correct size to create the proper vacuum and decrease the chances of leaking.
Poor fuel economy
People face several problems because of intake manifold malfunctioning, including poor fuel economy and sudden power loss.
Fuel economy becomes poor because incorrect air entry inside the combustion chamber draws more fuel for combustion. In addition, the fuel efficiency also decreases because of the poor air-to-fuel ratio.
You can also see rough idling, engine misfiring, and coolant leakages in your Ford F150. Inspecting the engine parts to resolve the coolant leakage and engine misfiring issues is better. You can also replace the intake manifold in case of severe and irreversible damage.
Carbon build-up
Carbon build-up on intake manifolds is common and can affect their normal functioning. It disrupts the working of the valve, allowing air flaps to open and close.
Carbon accumulates on their components because of using low-quality engine oils that seep over their parts. In addition, carbon accumulation also occurs because of incomplete fuel combustion in the Ford F150 combustion chamber.
Moreover, carbon is the ignition mixture’s by-product, accumulating over these components with time. You have to maintain their cleanliness to remove the carbon residues from their parts.
You can use additives that are used for carbon build-up removal. Use these additives after turning off the ignition and disconnecting the batteries.
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