What Happens If You Overfill Oil? Overfill Engine Oil Symptoms

You’re out on a drive and notice suddenly that your car is emitting all this dense, blue, or white smoke from either the engine bay or the exhaust. It’s possible that you’ve overfilled engine oil to your engine.

While it’s claimed to be hazardous to the environment, you will probably ask, can overfilling engine oil harm my car? Potentially, yes, it can. Also there are few overfill engine oil symptoms that we will discuss below.

What Happens If You Overfill Oil?

To find out how much oil is in your engine, check the oil stain on the dipstick. The stain will tell you whether it has exceeded the line that marks the maximum level, and by how much. The oil pan can hold a little excess oil, so exceeding the max line by a few millimeters or overfilling by half a quart of oil should be fine. 

Fluid expansion may happen during hot temperatures, so the engine is designed to accommodate it. However, your engine is overfilled if the oil stain is an inch above the max line. This is when it can be harmful to your car. 

Usually, overfilling your engine happens accidentally, as you or your mechanic can make an error in judgment. Ideally, you should change your oil regularly, around every six months or after clocking in five thousand miles. But even if you change your oil like a pro, overfilling is still possible. 

Don’t hesitate to double-check the oil level at the dipstick after each oil change. You can also refer to your car’s user manual to ensure that you are using the correct amount of oil for your engine’s size. 

Overfill Engine Oil Symptoms

When the crankshaft comes into contact with the excess oil in your engine, it whips it up and lets air into it, creating a foam that poorly lubricates the engine instead of the oil. The foam also prevents the oil from flowing altogether. The surplus of oil may also instigate unnecessary pressure in the machine, which may break seals and gaskets. 

sIn all cases, the engine will break down. Repairs will be costly enough, but a broken engine may also lead to other problems, such as leaks, twisted engine rods, the occasional damaged spark plug. Ultimately, you may need to replace the engine completely. 

Double-check your dipstick

The best way to fix this problem is to change the oil. Some will recommend draining only the excess oil, but it may be best to replace all of it and start fresh. Changing the oil on your own entails draining it out from the plug at the bottom of the pan, replacing the filter, and refilling the oil to the correct amount as marked on your dipstick. You should be able to sell the used oil at a recycling center. 

There are vacuums and oil suction pumps that can siphon the oil out of the engine from the dipstick tube at the top, but owning one may not be practical in the long run. This is assuming that you don’t plan to overfill your engine regularly and that you’ll be mindful of overfilling from now on.