What to Do If Engine Oil Level Increases?

[SanConnor]

If there is too much engine oil, it can be extracted. Use a syringe with a transparent tube, pull out the dipstick, insert the tube, and suck out the oil. When the oil reaches two-thirds of the tube, seal the upper end, pull out the tube, and drain the oil. Repeat this process multiple times to remove the excess oil from the oil chamber. The hazards of excessive oil are as follows: 1. Increased resistance in the operation of internal engine components, leading to unnecessary power loss. 2. Excess oil may enter the combustion chamber, causing the engine to burn oil, resulting in excessive exhaust emissions, blue smoke, significantly increased oil consumption, increased carbon deposits inside the engine, and even premature ignition, knocking, cylinder scoring, severely damaging the engine.

[VonLeo]

I just encountered the issue of oil dilution last month. The mechanic told me it's mainly caused by gasoline mixing into the engine oil, especially when driving short distances in winter. For turbocharged direct-injection engines like ours, during cold starts, unburned gasoline can seep down the cylinder walls. Checking it yourself is quite simple—pull out the dipstick and smell for gasoline or see if the oil is unusually thin, like water. My solution was to take a long highway drive to fully warm up the engine, and it returned to normal afterward. If you notice a milky, cream-like substance in the oil, it might indicate coolant leakage, and you should immediately visit a repair shop to check the head gasket.

[SanCarlos]

During the last maintenance, it was found that the engine oil exceeded the upper limit by two centimeters. The mechanic told me this is called fuel dilution phenomenon. Many new engines now use direct injection technology, and excessive fuel injection during cold starts can cause gasoline to seep into the crankcase. This is most noticeable in vehicles used for short commutes because the engine doesn't have time to warm up before reaching the destination. My personal experience in handling this: first, check if the coolant level is low, see if the exhaust pipe emits white smoke, and then feel if the engine oil is sticky. Recently, I've changed my route to take the ring expressway to work, keeping the engine at 90 degrees for half an hour. Last week, the oil level was back to normal. If the oil level continues to rise, it's best to check the fuel injector seals and the PCV valve.

[SanDante]

After driving for twenty years, this is the first time I've seen engine oil increasing while driving! An experienced mechanic taught me to pull out the dipstick and drip the oil onto a napkin. If the oil spreads quickly and smells like gasoline, it's definitely fuel dilution. Direct injection engines all have this issue, especially in northern winters. Now I've developed the habit of warming up the car for long trips, and if the single trip is less than five kilometers, I switch to an electric bike. By the way, don't overfill the engine oil during maintenance; it's best to keep it at the middle mark on the dipstick. Last time at the dealership, I saw a hybrid car with oil five centimeters above the upper limit. When they opened up the engine, they found the O-rings on the fuel injectors had deteriorated.

[BeauAnn]

90% of engine oil dilution is caused by gasoline mixing in. In our auto repair shop, we commonly see three scenarios: incorrect fuel injection angle, worn piston rings, or frequent short-distance driving under 3 kilometers. One customer's SUV had its oil level rise by half a liter every 2,000 kilometers. Later, we advised him to take a long-distance drive monthly, which alleviated the issue. For self-checking, you can open the oil filler cap after warming up the engine and smell for a strong gasoline odor. If you notice the oil turning milky white like milk tea, promptly check the cylinder head gasket, as leaking coolant can corrode bearings.

[DeclanLee]

Both of my family's cars have experienced engine oil dilution. The service supervisor taught me to watch for three signs: black smoke from the exhaust pipe during cold starts, engine shaking at idle, and a pungent smell when unscrewing the oil cap. Nowadays, new cars using low-viscosity 0W-20 oil are more prone to fuel mixing into the oil. During the last maintenance, the technician had me replace the PCV valve and adjusted the ECU fuel injection parameters, after which the oil level remained stable for six months. It's recommended to check the dipstick every 5,000 kilometers and not wait for the warning light to come on. If you're in the north, switching to winter-specific oil can make a significant difference.