What Causes the Engine Oil Cap to Be Too Tight to Unscrew?
2 Answers
If you have just driven the car, you can wait for the engine temperature to drop before attempting to open it. The oil cap may be difficult to unscrew due to excessive suction. Below is some information about engine oil: 1. Function: Engine oil is crucial for the engine. It not only lubricates but also cleans, seals, cushions, prevents rust, and dissipates heat. When the engine is running, the oil forms a thin film on the surfaces of various components, preventing direct contact and friction between them. 2. Precautions: Over time, the performance of engine oil degrades, so it needs to be replaced regularly. Failure to change the oil for extended periods can accelerate engine wear.
As a driver with over 20 years of experience, I've encountered the trouble of not being able to unscrew the oil cap, mainly due to thermal expansion and contraction. After the engine runs and the temperature rises, the metal parts expand, making the cap tighter. Dirt buildup or dried-up oil residue can also stick the cap, especially in older cars. Last time I dealt with it, I waited for the engine to cool completely, which made it easier to try, or wore rubber gloves to increase friction. Avoid forcing it open to prevent damage; you can spray some WD-40 to lubricate the threads. Additionally, the rubber seal on the cap aging and hardening or it being screwed on too tightly during the last oil change are common issues. It's recommended to clean around the cap during each maintenance to avoid dirt accumulation. If it really won't open, it's safer to seek professional help to avoid oil leaks causing trouble.
