My Oil Cap Won’t Come Off: What Can I Do?

If your oil cap won’t come off, you will not be able to check and change your oil, which can be disastrous to the engine after some time. Here’s what you should do in such cases.

Your car’s internal combustion engine requires oil to function effectively. The engine oil helps lubricate various components and lessens unwanted power loss. You need to change or check the oil level from time to time.

But what happens if the oil cap won’t come off? There can be numerous reasons for it, like if the teeth of the cap are damaged or exposed to rust or if the cap is shut too tight.

In this article, we explore these problems and what you can do about them.

Oil Cap Won'T Come Off

Why is it Important To Change Your Oil Regularly?

The engine of a car is made of various components. Almost all the components run at high speed and temperature. So, these components require oil for lubrication. There is an oil reservoir inside the car’s hood where you add oil.

The oil stays in the oil pan when the engine is not working. But when you turn the engine, the oil starts lubricating various engine components. This compartment is cordoned off by the oil filter cap, and this is why getting the oil cap stuck is a big problem. 

Why Is My Oil Cap Not Coming Off?

#1. You Have Not Changed The Oil For A Long Time

Oil can get dirty or contaminated with time, resulting in emissions that are harmful to the environment. Additionally, old oil can cause the engine to run slowly. It may also overheat the engine, damaging essential components.

If you don’t change the oil for a long time, a layer of burnt oil will form below the oil cap, and you won’t be able to remove it easily. Moreover, it will cause the cap to get stuck. So, you need to make sure to change the oil from time to time.

Remember, fresh, clean oil helps improve the engine’s performance. Most drivers check the mileage as a way to decide when to change the engine oil. It is usually recommended to change the engine oil every 3,000 miles. However, the frequency of oil changes in a vehicle depends on other factors, like the vehicle’s condition, oil quality, vehicle age, and how the driver drives the car.

So, you need to inspect the oil reservoir from time to time and change it. Moreover, remember that fresh oil is usually amber in color. But when the oil gets dirty, then its color changes. So, if you find dark-colored oil in the reservoir, then change it immediately, whatever your mileage.

#2. Warm Engine

Whenever the car is running, then the engine is quite hot. But it remains hot for some time, even after you turn the ignition off. If you try to open the oil cap during this time, the cap will blow out, or the hot oil can spurt out, causing severe burns on the driver. Lastly, sometimes the pressure created inside the oil chamber can cause the cap not to open.

So, you should change or check the oil only after your engine gets cool or back to normal temperature. It’s best to check the oil before you start the engine because, at that time, the oil will be at a normal temperature, and you can easily remove the oil cap.

Sometimes, you may be in a hurry and want to change the oil immediately after turning off the engine. If so, you should spray brake cleaner over the oil cap. It helps in cooling the cap, and you can easily remove it without any damage.

#3.Exposure To Rust

The oil cap can undergo wear and tear over time. For instance, the oil cap in most car models is made of iron. When the iron is exposed to moisture and oxygen, it can rust. The rust is usually orange-brown in color, and if you find this color just around the cap and it’s not opening, then the reason is likely to be rust formation.

Secondly, the oil cap has teeth in some car models. Constant opening and closing of the cap can break the teeth. Irregular teeth can cause difficulty in opening the oil cap. To solve either problem, you can apply some lubricant near the cap. It will help you in opening the lid easily.

#4. The oil Cap Is Too Tight

Overtightening of the cap is another reason why it may not open. The oil caps used in most car models have a ratcheting mechanism, which helps to prevent overtightening. But sometimes, this mechanism does not work, and the cap separates from the threads. Hence, it becomes challenging for the car driver to open the oil cap.

Using bare hands to open the cap is extremely painful. Fortunately, there are some tools you can use at such a time to open the cap. We have explained this in later sections.

#5. Gunk In The Oil Cap

There are grooves in the oil cap which enable it to fit properly. The grooves help the cap move when you are opening it. But if you don’t change your oil every three to four months, dust, dirt, and gunk will form on the grooves. Hence you will find it hard to remove the lid. It’s best to change the oil regularly because it helps remove contaminants.

Simultaneously, check the oil reservoir every few months; if it looks low, fill it with new oil. It will help reduce gunk on the cap, and you will be able to remove it easily.

Oil Cap Won'T Come Off

What Can You Do When The Oil Cap When Doesn’t Come Off?

You can remove a stuck oil filter cap in several ways; most of these involve cleaning up the cap and removing the gunk under it. Here’s what you should do.

#1. Apply Lubricant

Applying lubricant is one of the easy and most effective ways when the engine oil won’t come off. But don’t apply lubricant when the engine is too hot or in running condition because it will not be effective. You should wait 20 -30 minutes after you shut your car, or until the engine is completely cooled down, to apply lubricant.

Buy a good lubricant and put some of it on a clean cloth, and then rub the cloth near the oil cap. Leave the lubricant near it for a few minutes, and then try to twist it open.

#2. You Can Try Ice

Most car owners don’t think about using ice outside the oil cap. But an ice bag can help you in removing it. Allow the engine to cool down completely. Then take an ice bag and put it over the rim of the cap. Allow it to sit for a few minutes, and then try to remove it slowly. It should come off quite easily.

#3. Try To Clean the Junk

You can put some engine degreaser near the oil cap. Then take a toothbrush with medium bristles or a toothpick and try to remove all the dust, dirt, and junk from the rim of the oil can. Cleaning the junk will help in opening the cap.

What Are The Various Tools You Can Use To Remove The Oil Cap Easily?

#1. Slip Joint Pliers

You can use slip joint pliers to remove the oil cap easily. But don’t use slip joint pliers when the engine is hot. Allow the engine to cool, and then keep a cloth piece over it. Rotate it in a clockwise motion. It can easily remove the oil cap without any breakage.

#2. Strap Wrench

The strap wrench should be there in your toolbox. You can use this tool to remove the oil cap. The best thing about a strap wrench is that you can easily adjust its diameter. It will easily fit on the oil cap in any car.

#3. Vice Grip

A Vice grip is another great tool to remove the oil cap. But make sure the engine is in cool condition before using the vice grip. Wrap the oil cap with a soft cotton rag and use pair of vice grips to remove it. The long handle and the tool’s force will help you easily remove it.

#4.Channel Lock Pliers

If you failed to remove your oil cap by using any of the tools mentioned above, then you can use channel lock pliers. But using this tool will break your cap completely, so you will be compelled to buy a new one. But channel lock pliers will not break the nozzle, so if nothing else works, they are worth a shot.

Ways To Prevent This From Happening

If your oil cap gets stuck often, you should to follow the tips below to prevent it from happening.

  • You need to check the oil every two to three months. It will help in preventing burnt layers under the cap.
  • Clean the cap from time to time. It will avoid accumulating dust and debris under the rim.
  • Flush the oil from time to time and add new oil. It helps in removing contaminants from the oil.

Oil Cap Won'T Come Off

Frequently Asked Questions

How do you remove a stuck oil cap?

You can remove the stuck oil cap in the following ways.

  • Lubricate the surface of the lid
  • Use an ice bag and allow it to sit on the oil can for a few minutes
  • Use special tools like a strap wrench or vice grip.
  • Use engine oil in cleaning junk.

Can I remove my oil cap when the engine is hot?

No, you should not remove the oil cap when the engine is hot. It is dangerous to open the cap at this time. If the cap is loose, hot oil can gush out and cause burns on your hand. The lid may also blow out because of excess pressure. So, it’s better to wait for 15 -20 minutes. The engine will cool within this time, and you can safely and easily remove the oil cap.

What happens if there is too much oil in the engine?

Whenever you add excess oil inside the oil reservoir, then it causes extra pressure in the crankshaft, which may cause leaks. If the leak spreads over the flywheel, it can damage the transmission. Excess oil can even damage the sparkplug.

If you observe white smoke coming from your engine, it indicates too much oil inside the engine. Again if you find an oil puddle under your car, it also indicates too much oil inside the engine.

Can you put too much oil in your car?

No, putting in too much oil can be harmful.  Whenever you add excess oil inside the oil reservoir, then it causes extra pressure in the crankshaft, causing a big leak, and damage the transmission and even the sparkplug.

What happens if you over-tighten the oil drain plug?

When you overtighten the drain plug, then you will damage the threads. You will even damage the rubber gasket of the oil filter. Stripping off the threads can cause contaminants to enter the engine, which results in a decrease in power output.

How long can you drive without an oil cap?

The engine will work if there is sufficient oil inside the reservoir. However, driving without an oil cap is harmful to the engine. If you drive without it, the oil will spill from its chamber to the delicate engine components, which can permanently damage them.

There will be a lack of lubrication in the engine, as the oil may evaporate quickly, damaging them in the long run. So, driving your car without an oil cap is not wise.

Wrap Up

Maintaining oil levels is quite essential. It plays a vital role in the proper functioning of your engine. Not being able to change the oil can be very bad for the car and can cause severe breakdowns.

We have discussed the reasons why oil caps get stuck and the solutions for most of these problems. We hope these methods will help you open yours.

Thank you for reading this article!

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Sean Mendez

Hi, I am Sean, a self-confessed petrolhead. I live in Boise, Idaho with a busy family of four and our energetic Labrador retriever. Thank you for visiting my website. You can find my email on the contact page.

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