What to Do If I Overfilled a Car With Oil

by Kenny Soward
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Even if you have changed the engine oil in your car multiple times, there is always the chance that you will accidentally overfill it. Overfilling the engine oil in your car can cause serious damage to your internal engine parts and eventually lock up your engine. To remedy engine oil overfill in your car, you must first verify that the engine oil is actually overfilled and then drain the excess engine oil from your vehicle's oil pan.

Dangers of Overfilling

While it may not seem like a big deal to overfill the oil in your car, it can cause major malfunctions and potentially cost you thousands of dollars. When too much engine oil fills the crankshaft in your car, the oil becomes aerated and is whipped into foam. This is caused by the high rotation of the crankshaft. Foamy oil cannot lubricate your car well, and in many cases it will cause oil flow to halt completely, overheating your oil and causing loss of oil pressure. The engine then becomes starved for lubrication and may potentially lock up.

How to Check the Car Oil

If you have recently changed your engine oil and you see thick, white smoke fumes coming out of your car’s exhaust while driving, then you may have overfilled your car with oil. To verify your engine oil is overfilled, drive your car around for five or 10 minutes so that the engine becomes warm. This will ensure you get an accurate reading on the engine oil dipstick. With your car parked on a flat surface, open the hood and find the engine oil dipstick. Use your car maintenance manual if you have problems locating the engine oil dipstick. Pull the dipstick out and wipe off the excess oil with a rag. Reinsert the dipstick and wait a few seconds before pulling it out again. Investigate the fill line. If the oil reaches a point above the fill line, then you have overfilled the engine oil in your car.

How to Drain Excess Oil

If you have too much engine oil in your car, you must drain it from beneath the car. With a 3/8-inch drive socket wrench and a plastic oil pan in hand, crawl beneath your car and locate the oil plug. This will be a relatively large bolt at the bottom of the car’s oil pan. Reference your car’s maintenance manual if you have problems locating the plug. Place the plastic oil pan beneath the oil plug. With the socket wrench, loosen the oil plug until oil begins to trickle out. Continue to loosen the oil plug as much as you think necessary to drain excess oil. However, be careful not to loosen the oil plug too much, as it will result in a flood of oil.
Continue to check the oil dipstick until the oil level is even with the full mark.

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