Symptoms of a failing Upper Intake Manifold Gasket
Check engine warning light
I know, the light is small and looks insignificant, and as long as your car is driving well, what’s the worst that can happen?
You don't want me to answer that question honestly. The check engine light comes on for a reason. It’s an important reason. It illuminates because something is wrong with your car, and it needs to be addressed.
Many things can trigger the check engine light to come on, including a failing upper intake manifold gasket, which will impact the way that the engine runs.
Poor engine performance
Here’s the deal. Your upper intake manifold gaskets are responsible for sealing in the manifold, and keeping the improper amount of air from entering the system. When the gasket doesn’t do its job, the cylinders will get the wrong amount of air in them, which will disrupt the ratio of fuel to air. That will create an engine that doesn’t run very well, and you’ll feel that every time you hit the gas pedal.