Before All You Need to Know Driving Without An Oil Cap

Driving without an oil cap can be detrimental to a vehicle’s engine. Unfortunately, some car owners only realize halfway through a trip that their engine oil cap is missing after an oil change. This leaves them confused about whether to continue driving that way or find an alternative cover.

Since the engine oil cap is designed to fit into the hole, it won’t be easy to get a cover that suits the position. So, you may be contemplating, “What happens if I drive my car without the oil cap?” Even if it seems possible, this option is not ideal.

So, if you’re currently facing this challenge right now, this article provides a solution to your present predicament. Take a moment to find out what to do below.

how long can i drive without an oil cap

How Long Can You Drive Without An Oil Cap?

If you’re wondering, “How long can you drive without an oil cap?” Ideally, the answer is “0 miles.” Not because your car will suddenly stop moving, but driving without an oil cap will do more harm than good to your engine.

No matter what, if you discover that your vehicle’s engine oil cap is missing, do not succumb to the temptation of driving without the component. You may be risking severe engine damage if you do so.

In some cases, a driver may mistakenly forget to screw the engine oil cap on after an oil change, only to realize it at arrival. Usually, the oil will eventually spill from its place onto the engine and some delicate parts, resulting in unexpected complications.

The engine is designed to work efficiently with the necessary lubrication from the engine oil. Meanwhile, the oil is meant to cool and clean the engine and its related components while lubricating the moving metal parts.

In other words, the absence of the engine oil cap will create an avenue for the oil to escape, thereby resulting in low oil pressure, lack of proper lubrication, and friction between moving metal components in the engine.

Is It Safe To Drive Without An Oil Cap?

Of course not! It is totally unsafe to drive without your car’s engine oil cap. The component is designed to seal the hole through which oil is added to the engine in order to prevent the oil from spilling while the engine is running.

Is driving without an oil cap bad? Of course! When the oil cap is off its position, the engine oil will eventually spill out on the engine and other parts. Meanwhile, there’s a tendency for the fluid to move into areas where oil is prohibited, like the exhaust manifold or pipes, thereby causing unexpected steam of smoke and may even ignite the fire.

Also, when the oil is allowed to escape from the engine, it will not only result in poor lubrication but improper cooling of the engine. This may lead to engine overheating, which can cause serious damage to a car’s engine.

Is it dangerous to drive without oil cap? Of course, it is utterly detrimental to your car’s engine. So, if you discover that your car’s oil cap is missing after an oil change, ensure to get a temporal cover to seal the hole.

After that, drive straight to an auto parts shop to get a replacement as soon as possible. No matter what you do, never move an inch without your car’s engine oil cap.

loose oil cap symptoms


Q: What can I use as a temporary oil cap?

Duct tape is an excellent option to use as an emergency seal in place of your oil cap if you’re asking, “What can I use as a temporary oil cap?” The tape is a scrim or cloth-backed pressure-sensitive tape, which can help prevent the oil from spilling until you get a replacement.

You can also make use of a piece of a clean towel to cover the hole and hold it in place with a rubber band. However, it would be best to get a replacement immediately because you can’t trust any of these temporal fixes for too long.

Q: What happens if I lose my engine oil cap?

What happens if you drive your car without oil cap? If your car’s engine oil cap is missing, the positive crankcase ventilation system will pull in the air into the engine’s intake system from the breather tube cap. When this occurs, it will result in a vacuum leak.

The vacuum leak will pose a major challenge to your car’s engine because of the uncontrollable increase in the engine’s temperatures. This can trigger overheating and result in severe damage if not rectified on time.

Q: Can a missing oil cap cause a check engine light?

Of course, driving a car without an oil cap can trigger the check engine light. This is because the car’s computer system is designed to detect occurrences that are likely to affect the engine if not properly checked.

Therefore, it’s not enough to check your engine oil level or top it off at regular intervals; also, ensure to screw the engine oil cap on to avoid the check engine light illumination. So, if you see this light on after an oil change, ensure to verify whether you failed to screw the oil cap on.

Q: Can a loose oil cap cause a P0171?

Yes, a loose oil cap can trigger the P0171 trouble code in a car. This is because the absence of the engine oil cap will result in a serious vacuum leak, which further causes the oxygen sensor to pick the wrong readings.

Once this occurs, the inconsistency will affect the air-fuel mixture entering your car’s engine block and automatically pull the P0171 trouble code. If you suddenly see this code on your dashboard, ensure to contact an expert auto technician to diagnose and fix the problem ASAP.

Q: Will no oil cap cause low oil pressure?

Of course! The absence of a vehicle’s engine oil cap will eventually result in low oil pressure because the oil no longer has a covering for restricting it’s spill. Meanwhile, the constant spilling will reduce the oil level drastically until the oil pressure drops.

Low oil pressure comes with several side effects, including a decline in engine performance, poor fuel economy, stalling, etc. This is a serious issue that should be fixed as soon as possible before it degenerates into severe engine damage.

Final Words

No matter the time or place, never make the mistake of driving without an oil cap. If you were asking what happens when you drive without oil cap, the adverse effects of this improper practice have been unveiled above in this article.

Of course, you don’t want to risk sudden engine damage. Therefore, ensure to get a temporal engine oil cover if the cap mistakenly gets missing. You can use duct tape or a clean rag to cover the hole and hold the cloth in place with a rubber band.

However, do not manage this alternative for more than a day. Kindly replace the oil cap immediately at the nearest auto parts shop. This will only cost a few bucks.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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