What to Do If the Engine Oil Cap Can't Be Unscrewed?
3 Answers
Car engine oil caps can be opened using pliers or with specialized tools at a repair shop. The reason the oil cap can't be unscrewed is due to negative pressure and being screwed on too tightly. Adding engine oil requires opening the engine cover. Besides the negative pressure state preventing air from entering, causing excessive suction that makes the oil cap hard to open, another possibility is that the oil cap is too tight. You can wait until the car cools down before opening it. If you still can't open it by hand, you can use tools like pliers. Methods to unscrew the oil cap are as follows: 1. If the car engine oil cap is too tight to open, it is likely due to excessive suction. It's important to know that after the engine starts, it operates in a negative pressure state, creating a suction effect. If you're not very strong, you might not be able to unscrew it, especially for new cars where the gasoline cap's excellent seal makes the negative pressure effect more pronounced. In this case, simply wait until the car cools down, and you can easily open the oil cap by hand. 2. You need to open the engine cover to see the engine oil filler port. Sometimes, the car engine oil cap can't be opened due to negative pressure and being screwed on too tightly, but you can use pliers or specialized tools at a repair shop to open it. Adding engine oil requires opening the engine cover. 3. Engine oil is the source of a car's power. It plays roles in lubrication, sealing, cleaning, heat dissipation, buffering, and rust prevention within the engine. One essential car maintenance task is changing the engine oil. By unscrewing the oil pan's drain plug, the old engine oil is drained, and then new oil is poured in, completing this maintenance task.
I've encountered the issue of not being able to open oil bottle caps several times during oil changes. The most effective method is to use rubber gloves to increase friction - twisting becomes much easier when wearing them. If gloves don't work, you can wrap a rubber band around the cap or rinse it under running water to remove grease before trying again. Another possibility is that the cap is too tight due to vacuum suction inside - wait a few minutes for pressure to equalize before attempting to open. Never use a hammer to force it open as this may damage the bottle neck or cause oil spills. During regular maintenance, remember to wipe oil residue from the bottle opening and periodically check the cap's seal to prevent sticking. Address stuck caps promptly to avoid oil leaks affecting the engine. Always be patient and prioritize safety - most cases can be resolved with common household tools.
When the oil cap won't open, I usually first check if my hands are oily and slippery, then dry them with a cloth before trying again. If that doesn't work, I spray some lubricant like WD-40 into the edge gaps and wait a minute or two for it to penetrate, which can make the metal slippery. Then, I use a wrench or pliers wrapped in a towel to gently twist, avoiding direct force that might hurt my hands. Remember, newly purchased oil bottles might have caps tightened too much at the factory, or old caps might be stuck due to oxidation—trying again later is also an option. For daily maintenance, keep the cap clean and properly lubricated to prevent the same issue next time. If repeated attempts fail, it might be necessary to replace the cap or seek professional help, but never force it to avoid causing more trouble.
