How Long Can You Drive Without an Oil Cap? Answers and Advice!

Driving with no oil cap is not an ideal situation to be in. Nonetheless, these things happen. But how long can you drive without an oil cap if you are in this predicament?

To be blunt, you won’t get very far without an oil cap, and it would be better to arrange a temporary fix and then seek a new cap. To start with, it’s pretty difficult to lose an oil cap; the only reason you would remove it is to fill the engine with oil. In which case, place the oil cap somewhere it can’t be lost. On top of the scuttle tray (wiper tray under the windshield) is a great idea, but if you forget to put it back and drive up the road, the wind will catch it, and it might be lost forever.

If it falls into the engine bay compartment, it will still be retrievable; it’s got to come out of the bottom, right? So, putting it on top of the engine block next to the oil filler neck would be a better idea, at least somewhere in eye view where it will be difficult to forget to put it back. But let’s say it’s already too late. It’s lost; well, you better read on.

Can You Drive Without an Oil Cap?

Technically, you could drive without an engine oil cap; the engine will not shut off or cause problems because the cap is missing. There aren’t any cars on the market with sensors to determine that the cap is there. However, driving without an oil cap will lead to problems because it is there to keep the engine oil inside the engine.

How Long Can You Drive Without an Oil Cap?

Realistically, you could drive about a mile or two without an oil cap, and the only issue you may experience is a giant mess under the engine bay! This depends on how fast you drive; the higher the revs, the more oil will spit out. If the engine was running at a standstill, expect to start noticing an issue after 10 minutes. 

The problem isn’t that you’re driving without a cap for this very short distance; it’s just that the cap’s job is to keep the oil inside the engine. So, expect that oil to spit out.

Driving further than a handful of miles, you can expect more severe problems than a mess to clear up to start presenting themselves.

What Happens if You Drive Without an Oil Cap?

Driving without an oil cap is problematic for three main reasons:

  1. It would lead to driving low on oil. Driving with very little or no oil in the engine would cause the engine to become dry, and the rotating components would eventually seize without any lubrication.
  2. The cap stops the oil from being thrown out of the top of the engine. As we’ve already pointed out, the oil has only one place to go, with no plug at the top. And let me tell you, the mess oil makes, the smell and smoke pouring out everywhere as it leaks onto a hot engine, is just a nightmare to clean up. Not only that, but it can also damage electrical components if the oil gets into them, which will most likely then result in the engine misfiring.
  3. Dirt and debris can get into the engine without an oil cap. Debris will make light work of destroying an engine, even if there is still plenty of oil.

It is all doom and gloom, but it isn’t worth the hassle of driving a car without an oil cap. Instead, you can use lots of household items as a temporary oil cap replacement.

What to Use Instead of an Oil Cap?

Before you read further, whatever you use instead of an oil cap is a temporary solution only. One thing to note is no matter what you use; it must be a larger diameter than the oil cap hole and not of a material that could be sucked into the engine. Trying to block the hole with some scrunched-up newspaper would be disastrous.

It isn’t easy to tape anything to an engine, but you may be able to duct tape something like the top of an old tin can. You can be creative here; an old shoe, anything you may have lying around in the car, might work very temporarily to stop the oil being thrown from the top of the engine.

You could use an old rag, cable ties, and duct tape as a last resort or in an emergency. Cable tie a bit of the old rag around the outside of the oil cap filler neck, then duct tape it down. As pointed out earlier, there is a risk the rag could get sucked into the engine, so I wouldn’t recommend doing this unless there were no other options. You need to ensure the rag won’t just fall off as soon as you start the engine, so ensure it’s secure.

When using a temporary oil cap solution, you must avoid driving the vehicle hard and keep the RPMs down to the minimum, or you risk dislodging the makeshift cap and causing a problem.

Engine oil caps are relatively unique to each vehicle brand, so the cap from a BMW probably won’t fit on a Peugeot. This might mean you need to seek a dealership to get a replacement. Some auto parts stores may stock an aftermarket branded version. Once your temporary repairs have been done, that’s probably the only place you want to drive if you have to. Equally, a local mechanic may have the one you need lying around.

Bottom Line

Driving without an oil cap is not recommended; trying a temporary repair and getting a replacement as soon as possible is a much better idea. Even better than that, don’t drive if you can help it and get a replacement as soon as you identify yours is missing. It’s difficult to lose your cap, but to answer the question, how long can you drive without an oil cap? Only a mile or two, or with the engine running for no more than about 10 minutes.

My name is Tom although my friends call me Tommy. Messing around with cars and bikes has always been a hobby of mine even from a young age. So I made it my day job 17 years ago. I am a fully qualified mechanic as you would expect. I've worked in all different areas of the motor trade, valeting, panel beating, engine repairs, I'm sure you get the idea. I enjoy sharing my wealth of knowledge and experience with others, which is the reason I spend a lot of time here writing for this website.

6 thoughts on “How Long Can You Drive Without an Oil Cap? Answers and Advice!”

  1. I drove about 30 miles without the oil cap on. When I got to my destination, I did finally replace it back on, but yeah, some oil cam out. But, now it is back on. Will it be ok?

    • Thanks for your comment. If you haven’t already, recheck the oil level make sure that’s ok. If the motor still had quite a bit of oil in it when you refitted the oil cap, you won’t have caused internal engine damage. To be honest providing it didn’t completely run dry which I doubt it did in 30 minutes, you’d be ok.

  2. Hello,

    I think I last changed my oil maybe 4 weeks ago. I forgot to add the cap, and when I opened the bonnet today, I find it has spilt. I think it might have been dry (not super thick), but there was still oil all up the measurement tool, just thinned out, and I think I repeated this a few times. Unsure if safe to drive, or what to expect. For example I drive around often, so will it eventually break down if I ignore any potential damage to the engine, or can I drive and save for a mechanic over the following weeks.

    • Thanks for your question. If you still need to replace the cap, get another oil cap ASAP. Providing the engine has never run out of oil, you may be able to get away with just carrying out an oil change to remove any contaminants that may have fallen into the engine. This will also add to causing internal engine damage, so get this done immediately.

      Having someone look over the car regarding potential engine damage is a good idea. I wouldn’t want to say you are or aren’t safe to drive while you save without seeing the engine running, driving the car, and hearing for any potential problems myself. But providing the engine never ran out of oil and has not been run dangerously low on oil, engine damage is not that common.

      Please let me know if you have any more questions


  3. Thanks for informative post. I changed oil today at a dealership. After drinving almost 150 kms, I notices some smoke coming out from the front of car. I stopeed and opened the bonut and saw oil everywhere and no cap there. The technician forgot to put it on. The dealership was closed at that time and I will go tomorrow. How should I be compensated for this negligence of dealership?

    • Thanks for your comment. It would be wrong for me to say you are entitled to X or Y because every situation like this is unique. For example, has the engine now run dangerously low on oil that it has caused damage to engine internals due to the dealerships negligence? However, I would certain be looking for the car to be cleaned, inspected correctly, and the work carried out again at the very least!
      Good luck!



Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.