Most car owners are aware that driving with too little engine oil will ruin your engine. But what happens when you put too much oil in your engine?
Oftentimes, it can be difficult to determine how much oil to add when topping off the engine oil in the car to ensure the perfect level at the max mark on the dipstick. It is easy to make a mistake and put too much oil into the engine.
So what happens, and what should you do if you accidentally overfill your car’s engine oil?
This article will discuss what happens if you put too much oil in your engine and what you should do about it, as well as some of the most common questions regarding overfilling a car engine oil.
What Happens If You Put Too Much Oil in Your Car?
Adding too much oil to your engine can create an issue with foaming of the oil as the crankshaft will hit the oil. Luckily, if the level is only slightly above, it is not an urgent indicator to do anything about it.
But, overfilling is a problem if it is 0.2” or greater over the MAX mark. You will need to drain some oil.
The engine oil reserve has some extra margin to account for the fluid expanding with hot conditions. Adding an extra half a quart is generally not an issue for your engine. However, anything greater than that can be an issue to your engine.
So, when you add too much oil the excess oil will go to the crankshaft, and then as the crankshaft spins at a high-speed, the oil is mixed with air, and ‘aerates’, or foams.
The foamy oil is a very bad lubricant, and once the oil is foamy, the oil does not get pumped as efficiently. Over time, the engine will run without proper lubrication, and depending on the oil pump it could get locked up.
The Effects Of Too Much Car Oil
Overfilling your car’s engine oil can result in these problems:
- Foamed Engine Oil – Excess oil causes the crankshaft to churn the oil, creating foam in the oil pan. Foamed oil is harmful to your engine because the foam can push air bubbles throughout the engine.
- Burned Oil – Combined with excess oil in the engine, this can lead to increased crankcase pressure. The higher pressure can push excess oil into the combustion chamber. You’ll see blue smoke from the exhaust if combustion is happening.
- Fouled Spark Plugs – When oil is needed in the combustion chamber, oil will coat the spark plugs. Oil fouling spark plugs leads to misfires in the engine.
- Failed Seals and Gaskets – Again, excess oil leads to excess crankcase pressure. Some types of engines may blow seals or gaskets. Look for oily areas around your engine, which may indicate a failed seal or gasket due to oil pressure or oil seen in the engine crankcase.
What Are The Symptoms of Overfilled Engine Oil?
The most common sign that you have added excessive oil and that the oil level is too high is when you see an oil leak on the ground or blue smoke from the exhaust. It may also cause a warning light on your dashboard.
Sometimes you may not be aware whether you or the mechanic overfilled your engine oil, but if you see any of these signs, there could be a chance your oil is overfilled:
- Oil leak.
- Burning smell of engine oil.
- Smoke from the engine bay.
- Smoke from the exhaust area.
- Engine making too much noise.
- Engine Oil Pressure Light on your dashboard.
How Much Is Too Much Oil In A Car?
If you want to be safe, anything above the MAX mark on the dipstick is too much. However, if you overfilled the oil by half a quart (or less), you probably have no worries.
But if the oil level is 0.2” or more above the max mark on the dipstick (or you see foam), it’s time to drain some oil.
How much oil to add before it is critical to the engine is dependent on the engine type. Generally, older engines are less sensitive to higher oil levels, so if you have a modern engine, you’ll need to be careful about overfilling.
How To Fix Overfilled Oil?
To solve the overfilled oil, you’ll need to drain the engine oil or be prepared to do that. You can get oil out in two principal ways with a suction pump or simply drain it out through the oil plug.
Easily, you want to drain the oil out through the oil plug because this doesn’t usually require special tools.
The alternative with a suction pump is that you don’t have to lift the car and get underneath it. But you do need a special pump and air for it, and most do not want to spend money on a tool that they will only use once or twice.
The most common way is to drain it by the oil plug. If you are not familiar with working on cars it can be somewhat messy and sometimes difficult, so you may want to have a mechanic do that for you if you are unsure.
If you are draining the oil through the oil plug, here’s what you do:
- Lift the vehicle and place jacks underneath it for safety
- Unscrew/remove the cover under the engine if you have one.
- Locate the oil plug (If you’re not sure, look in your repair manual to find it)
- Remove the drain plug and drain the engine into a bucket with the amount you overfilled it with (generally about 1 quart).
- Replace the oil plug and tighten to the specification.
- Replace the cover and lower the vehicle to the ground.
- Start the vehicle for 3 minutes and shut it off.
- Wait 5 minutes and check the oil level.
High Oil Level Without Overfilling
If the engine oil level is above the max mark but you are confident that you or your mechanic didn’t overfill it, there is another reason for this.
If you are only going short distances and allowing the oil to warm up at a proper temperature, the engine oil could eventually be filled with gasoline that won’t evaporate until it reaches another temperature.
This will cause the oil level to rise and can actually be hurtful to the engine too.
If you notice the oil is too high and it is because of gasoline in the oil, it is still best to get an oil change and start driving this vehicle to longer trips to prevent this from happening.
FAQs.
Can You Drive a Car with Too Much Oil?
In general, you shouldn’t drive a car with too much oil because it may cause the oil to foam and air bubbles can ultimately disrupt the oil pressure channels inside the engine, which is bad and can cause it to seize depending on how unlucky you are.
If you overfilled the oil, but only by a small amount (for example, 0.2” or less under the max mark) then in most cases, you don’t have to be overly concerned.
How Long Can I Run My Car with Too Much Oil?
Although you shouldn’t drive it at all if you put too much oil in the car in most cases, how long you can drive with too much oil in the car depends on how far you overfilled it.
If you overfilled it by a small amount (e.g. 0.2” or less over the max dipstick mark), you probably wouldn’t have to be overly concerned. If you overfilled your car by more than that, you best to drain your oil as quickly as you can.
Will an Extra Quart of Oil Damage My Engine?
Yes, indeed. Actually, one extra quart of oil could tease damage if you’re unlucky depending on the engine type, because some engines are more sensitive than others to too much oil. This simply depends on the distance between the crankshaft and the oil pan.
However, with all of that in mind, it is best not to take the chance with just a quart of oil overfilled, because it is simple enough to drain the extra quart.
Can 1 Liter of Extra Oil Damage An Engine?
Yes, even a single excess liter of oil can harm the engine, depending on the engine design type. Due to engine damage risk, it is best not to risk it and to drain the oil. If you’ve only overfilled it by half a liter it will probably be quite safe in most engines. However, 1 liter is likely too much.
What Happens When The Oil Level Is Above Max?
If the oil level is above the max but only slightly, below 0.2” for example, most likely nothing will happen depending on the engine. If you fill it too much above max, the crankshaft will hit the oil level and foam the engine oil. This could cause engine damage.
Can Too Much Oil Cause Engine Noise?
Yes, too much oil can foam engine oil which causes the crankshaft to hit the oil level, causing some noise. Foamed engine oil can make tiny air bubbles push through the oil pump into the hydraulic lifters and other engine parts that require proper lubrication. This could cause the lifters to malfunction and make a ticking sound that comes from the lifter.
How Much Engine Oil Should I Fill In My Car?
To validate how much oil your engine utilizes, references are in the owner’s manual. Most engines will run with somewhere between 3 and 8 quarts of oil but varies a bit with engine size approximately.
For example, the 4-cylinder engine utilizes 3 to 4 quarts, while a larger 6-cylinder engine might be around 6 quarts.
Can Overfilled Engine Oil Blow The Head Gasket?
Not really. In most cases, too much engine oil will not create a blown head gasket. Overfilled engine oil can create an oil leak which will create smoke from the engine bay or in the exhaust and can be very similar to symptoms of a bad head gasket.
Will Excess Oil Burn Off?
Finally, excess oil will burn off depending on the engine type as well, as some engines burn more oil than others. However, it also can still cause engine damage and you might not be fortunate enough to burn everything off before engine damage occurs.
In conclusion, just drain the oil instead of waiting for it to burn off would be the best option.
Summary
Overfilling your engine oil can cause foamed engine oil, serious engine damage, or ruined engine components that cause you to whole engine replacement which certainly will not be inexpensive. If it’s just above the MAX on the dipstick, which on most cars is over 0.2″, you must drain the oil. Better safe than sorry!
Overfilling engine oil in your vehicle may seem harmless, yet engines don’t always handle it well which is great risk you don’t want to take.
Driving with excessive oil in your engine results in catastrophic impact and complete engine failure. You’ll be looking at a whole engine replacement, you know that’s not cheap!!
Have checked the oil, the dipstick rises, you’ve overfilled the oil, even if you don’t enjoy draining oil, its as cheap insurance for your car, plus it’s not difficult, you either suck it out or do it through the oil plug.
I hope this article helped you with the questions you had about overfilling engine oil and now have the knowledge on what to do if you’ve overfilled engine oil.