Do you feel the need to replace your vehicle’s engine oil cap, but you are not sure? 

Well, you might think that it is a minor component that does not need much attention, but it is not that simple. The size of an engine oil cap might be small, but the significance is not. One might not understand the importance of this tiny component till they end up losing or damaging one. 

Even after you are convinced that you need to replace this tiny engine oil filler cap, most car owners would ask, ‘Are engine oil caps universal?’ 

Here is the answer, if you are looking for a replacement for your engine oil cover, a random one is not a solution. Yes! No matter how many options you find in the local stores or the products available online that are incorrectly labeled as ‘universal’; they are not all the same. 

Though some vehicles can use engine oil caps interchangeably, not all oil caps are fit for all vehicles. For example, there are high chances that one can replace the engine oil cap of the Chevrolet Silverado 1500 with the GMC Sierra 1500. However, the same arrangement will not work out between Chevrolet Silverado and Mitsubishi Eclipse. 

Before we get into the details of how and where to buy an engine oil cover, let’s get into the details of why you would need to replace the cap. 

These reasons could be:

  1. A broken or loose engine oil cap
  2. A missing engine oil cap

Let us discuss these reasons one by one:

  1. A broken or loose engine oil cap- If your engine oil cap is physically damaged or ill-fitted, this will stress the oil chambers and the oil will start leaking. This could happen with a wrong buy, wear-and-tear, a loose gasket, among other reasons. 
  1. A missing engine oil cap- If this has happened to you, trust that you are not alone. Many people lose their engine oil cap at the car dealership. Often engine caps get exchanged with other vehicles at the repair shops. A lot of times people end up dropping the engine oil cap into the engine bay while handling it. This can be quite dangerous for your vehicle.

Both the above situations call for the replacement of the engine oil cover.

Let us first understand the importance of oil caps. Here are some important facts, details, and useful tips related to engine oil caps that could help you.

What is an Engine Oil Cap

Usually sitting on top of the engine, the engine oil cap is a round cover of 2-.5 inches in diameter. An engine oil cap contains many kinds of materials ranging from rubber and plastic to a mix of metals of the likes of aluminum and iron. The oil cap plays a vital role in keeping your engine healthy and running. 

Why is the Engine Oil Cap Essential

Modern vehicles are complex machines that have many components like rings, pistons, valves, and nozzles. When the vehicle runs, all these parts produce heat and friction. The purpose of engine oil is to keep the engine cool and friction-less during this process. Here is where the engine oil cap keeps the oil inside and helps in the proper functioning of the engine. Hence, missing the cap or having the wrong one could cause engine oil to leak, leading to abnormally high temperatures and over-heating. 

What can happen when you lose your engine oil cap or drive your car with a dysfunctional one?

The importance of oil in the smooth functioning of the engine is imperative. Driving a car without the right engine oil cover it deserves can lead to serious engine problems. Look out for these signs: Trouble starting the car, frequent need for cleaning and servicing of the vehicle, engine damage, and though we could have other issues causing such vehicle breakdowns, a poor engine keep is also something that can trigger this. Here are a few damages your vehicle faces without a functional engine cover:

Malfunctioning of the PCV system

PCV system stands for Positive Crankcase Ventilation system. When an oil cap is missing, your vehicle’s PCV system pulls air inside the engine from into your car’s absorption system, which could eventually lead to a vacuum leak if not addressed in time. These vacuum leaks may kill your engine by cranking up the temperature.

Lubrication Issues

One of the primary concerns, when one drives a car with a dysfunctional cap, is the oil escape. When the oil starts spraying out of the engine, your overheating problems might kick start some serious engine damage. After a significant amount of oil has gotten away for a long haul of time, the engine’s friction resistance drops significantly, which directly affects the vehicle. So, driving without an oil cap will show signs of severe engine damage after a few miles. 

Foreign Particles

With an inadequate guard on your engine oil filler, physical particulate matter such as dust and debris can make its way into the engine. Once the dust particles get into the open engine oil compartment, you could see the problem signs. When dust and debris go into the engine at this rate, the oil filters, too, do not offer great relief, and eventually, the engine takes an adverse hit. While there are oil filters that can keep the dust and debris from getting into the engine parts, the debris will eventually influence the engine’s functions negatively.

Friction due to alien particles

It is not just the absence of oil that causes resistance in the engine, but the presence of debris inside the engine parts has its own part in generating friction inside the engine. This grinding, then, leads to physical engine breakdowns.

Water vapors and air

Driving a vehicle without the engine oil cap leaves the engine vulnerable to sucking water vapors and air in also. This intake of unfiltered air directly can also lead to engine fire sometimes.

In an ideal situation, you must depend on your second vehicle or taxi till the time you receive the correct replacement. However, if you have to drive to reach your destination or the store, always make sure to keep your RPMs and accelerator as low as possible.

While driving a car with a dysfunctional or no-engine oil cap is highly discouraged, sometimes one might not have an option. Hence, it is important to create a makeshift sealing arrangement to sustain minimum engine damage. This could help you cover up the open cavity and protect your engine against dust, debris, and excessive spillage. 

Here is a guide that can help you create an adequate arrangement in such a situation till the time you reach the nearest professional or an equipped auto store: 

For the temporary arrangement, you will need the following things:

  1. A rag or a towel,
  2. A pair of scissors or a knife, 
  1. Some masking tape or a zip tie

Image Source: Roadkillshow, comments, Reddit

Here is a step-wise guide to the makeshift arrangement:

  1. Twist the towel or the rag tightly and shape it like a cone to fit the open hole to replace the oil cap. 
  2. Make sure that you cut out the extra piece of cloth to avoid any fire hazard. 
  3. Now, cover the cloth tightly with masking tape or zip-tie to stop the air from entering the engine and save your engine from getting soaked because of the oil leakage.

Always remember, this is just a hack that temporarily helps you get through the moment. The permanent solution is always finding your engine oil cap or buying a new one that fits well. 

Pay attention where you lose the cap

In most cases, you could lose the oil cap at the site where you or a professional worked on the engine. The other place where one can lose the cap is the engine bay of your vehicle. Though just buying a new one seems like a simple solution, but, it is not! 

It is not so important to find the cap for the well-being of the car, but leaving it in the bay is potentially more dangerous for your vehicle. Here is what could happen:

  • The melting of the cap rubber produces a powerful odor, which can be suffocating for the driver.
  • It can cause friction in any two parts of the engine and trigger serious engine devastation.
  • It can cause an unexplained obstruction in engine operations.

So, either take out the cap yourself or approach a professional for help. 

What is the Ultimate Solution

The best solution is to replace the lost or damaged engine oil cap with a new cap that is made for your vehicle. This is essential because the price of restoring or replacing your engine is much higher than spending a reasonable amount on fuel cap as soon as possible. 

With the automobile and spare part industry being as big as it is today, there are many avenues where you can find superior quality engine oil cover for your vehicle. 

These could be:

  1. The most reliable source is your auto dealership where you service and repair your car, but, this might be a little heavy-on-the-pocket and time-consuming too.
  2. The other trustworthy place is a well-stocked auto parts store. Here you can find a mix of many options, but, you will need to go there yourself. This might be a little overwhelming for first-time shoppers.
  3. If you can wait and you are looking for a cheaper option that comes home to you, going online is ideal for you. However, research is important as not all engine oil caps are the same. Just a universal label does not guarantee a perfect fit for all vehicles.

So, if you are looking for a perfect fit that ensures a healthy engine, your vehicle’s dealership is the best place for you.  

Just in case you plan to proceed with this purchase online or at a local store, do not blindly follow the universal tag. Keep the following things in mind:

  • Read the description carefully
  • Go for the product that has a list of compatible vehicles specified as no product is 100% universal.
  • Go for more popular and well-established brands.
  • Read the reviews from previous buyers on the internet.
  • Talk to an expert before you invest.
  • Buy over one kind of product. In case one does not fit, the others could. 

Besides the above, when you invest in a universal engine oil cap that seems to fit well, being vigilant is a good idea as there is nothing like universal in engine oil caps. There are many signs to watch out for that can help you understand if your engine oil cap is made for your vehicle or not. 

Here is a list of symptoms of a poorly fitted oil cap:

  1. Loss of oil- A loose or ill-fitted engine oil cap lets the oil escape through it. This leads to major oil spills and eventual money loss repetitively.
  2. Oil spray on the engine- While the engine runs with the wrong engine oil cover under the hood, the oil leaks out and sprays all over the engine. It creates a mess on an otherwise clean engine. 
  3. Oil seems contaminated every time you go for service- Since the cap is dysfunctional, the dust particles can still keep entering the oil cavity and make your oil dirty way sooner than its actual timeline.
  4. Smoke from under the hood- If the engine oil sprays onto the hot engine components, it can cause smoke to get trapped under the hood. One can see this smoke come out right in front of the windscreen, which makes driving unsafe. 

Image Courtesy: The Roadguy

Pro tips on avoiding an engine cap situation in the future:

  1. At every service, insist on the inspection of the engine oil cap.
  2. Even if you have a reliable professional who worked on the car, always double-check that they have replaced the cap.
  3. The best way to ensure that you don’t forget about the engine cap is that you always place the oil cap near or on the hood latch. This obstructs the hood from closing and reminds you to secure the cap properly.
  4. Do not leave the cover on top of the engine and turn the ignition on, since the vibration can throw the cap into the engine bay.

Conclusion

Replacing a dysfunctional oil cap is easy but driving without an engine oil cover or with a defective one is neither easy nor safe. The risks associated with driving your vehicle without a proper engine oil cap come with repercussions that are not worth it.

Buying and installing a proper engine oil cap is not a choice, it is rather essential.

Choosing an incorrect oil cap that does not fit properly poses hazards like engine fires, debris penetration, oil contamination, and total engine failure too. Always remember, engine oil caps are not made with universal parameters, and so, they are not identical,  and not every cap labeled as universal is fit for your vehicle.