The possible locations and components that *might* be referred to as an "air check valve" include:
* PCV (Positive Crankcase Ventilation) valve: This valve is part of the crankcase ventilation system and helps regulate pressure in the engine crankcase. It's usually located on the valve cover.
* Air intake system: There might be a check valve somewhere in the air intake system (e.g., related to the emissions system or a secondary air injection pump). The location would vary considerably depending on the specific system design.
* Brake booster: The brake booster has a check valve to prevent brake fluid from going back into the vacuum line. This is not directly related to the engine's air intake.
To accurately locate the component you need, please specify:
* The symptom you're experiencing: (e.g., rough idle, vacuum leak, check engine light).
* The specific part you're looking for: (if you have a part number or diagram).
* The context in which you heard the term "air check valve": (e.g., a repair manual, a mechanic's instruction).
With more information, I can provide a more precise answer. A repair manual specific to your vehicle's year, make, and model will be invaluable in this situation.
