What are the symptoms of a damaged oil check valve?
2 Answers
Symptoms of a damaged oil check valve include extremely unstable idling, even stalling, flashing warning lights, failure to meet emission standards during annual inspections, oil burning, and blue exhaust smoke. A damaged oil check valve cannot be repaired and must be replaced. Classification of oil check valves: Check valves come in two types: straight-through and right-angle. Straight-through check valves are installed on pipelines via threaded connections. Right-angle check valves come in three forms: threaded connection, plate connection, and flange connection. Hydraulic check valves, also known as locking valves or pressure-holding valves, function similarly to check valves by preventing reverse oil flow. However, in hydraulic circuits requiring reverse oil flow, control oil pressure can be used to open the check valve, allowing oil to flow in both directions. Working principle of oil check valves: Compressed air enters through port P, overcoming spring force and friction to open the check valve, allowing compressed air to flow from P to A. When there is no compressed air at port P, the valve remains closed due to spring force and residual air pressure at port A (chamber), preventing airflow from A to P. Check valves are used in applications where reverse airflow is not allowed, such as between an air compressor and an air tank. When the air compressor stops working, the check valve prevents compressed air in the tank from flowing back into the compressor. Check valves are also often combined with throttle valves, sequence valves, etc., to form one-way throttle valves or one-way sequence valves.
When the oil check valve is damaged, I notice that the car has difficulty starting, especially when cold, with the engine rattling severely as if struggling. The oil pressure warning light frequently flickers or stays on, indicating unstable oil pressure. The car emits abnormal noises at idle, and insufficient lubrication leads to accelerated component wear. Over time, the engine temperature rises, affecting performance. I observe increased fuel consumption, weakened power output, and even the risk of premature major repairs. Cold weather worsens the symptoms because the oil viscosity is higher, and the oil flows back faster when the check valve fails. It is recommended to regularly check the oil pressure gauge readings or visit a professional shop for diagnosis, replacing the faulty part early to avoid safety risks and financial losses.
