Does adding too much engine oil have any impact?

[ReidLee]

Adding too much engine oil does have an impact, specifically: 1. Increased fuel consumption; 2. During engine operation, various components will experience intense agitation, increasing internal power loss; 3. Increased resistance on the crankshaft, affecting power output; 4. Worsened exhaust emissions, which in severe cases may cause the three-way catalytic converter to become poisoned and damaged. Engine oil, also known as engine lubricant, serves to lubricate and reduce friction, assist in cooling, seal against leaks, prevent rust and corrosion, and provide shock absorption. Engine oil consists of two parts: base oil and additives. The base oil is the main component of the lubricant, determining its basic properties, while additives compensate for and improve the shortcomings of the base oil, imparting certain new properties, making them an important part of the lubricant.

[DeHarper]

Last time I got my car serviced, I overfilled the engine oil by half a liter and jokingly said more lubrication is better. But after just three days of driving, problems emerged. When I stepped on the gas, the car felt like it was dragging a block of iron, struggling to accelerate. A friend sitting in the back even smelled engine oil. The mechanic explained that excess oil gets whipped by the crankshaft, creating bubbles. These foam bubbles then enter the lubrication system through the oil pump, causing hydraulic lifters to tick. The worst part is that when pistons move downward, the oil rings can't properly scrape off the excess oil. This not only leads to oil burning (blue smoke) but can also clog the catalytic converter. The mechanic emphasized that the oil fill line isn't just for show - if it's overfilled by even 1cm above the max mark, you need to drain it. The easiest method is using a syringe with tubing inserted through the dipstick tube to extract the excess oil.

[LePatrick]

I've seen many car owners believe that adding more engine oil is safer, but in fact, the consequences can be quite serious. When the oil level is too high, the high-speed rotating crankshaft will repeatedly churn the oil in the oil pan, much like a whisk beating cream, creating a large amount of foam. These bubbles entering the lubrication passages can cause oil starvation at bearing positions, leading to damage. I've noticed that some engines may also leak oil from the oil seal positions, as the rubber seals can deform and fail under continuous high-pressure oil impact. It's recommended to check the dipstick when the engine is cold after maintenance, with the oil level ideally at the 3/4 mark between the upper and lower limits. For DIY solutions, you can use a modified dish soap bottle as an oil extraction tool to remove excess oil in just ten minutes.

[CamillaAnn]

When engine oil exceeds the upper limit of the dipstick: 1. The resistance of the crankshaft stirring oil increases, leading to a fuel consumption rise of approximately 5%; 2. Foamy oil causes abnormal noise in the hydraulic lifters; 3. Oil entering the combustion chamber may clog the three-way catalytic converter; 4. Excessive crankcase pressure can damage the valve cover gasket. Recently handled a Nissan Sylphy case where post-maintenance fuel consumption surged from 7L to 9L. Removing 300ml of excess oil immediately restored normal levels. Teach everyone self-check: Park on level ground, turn off the engine for 10 minutes, pull out the dipstick, wipe it clean, reinsert it, and the oil level should be within the grid area. If exceeded, use a shampoo pump head connected to an infusion tube inserted into the dipstick tube to extract oil.

[SanMiles]

As a mechanic with 20 years of experience, the worst thing I see is owners randomly adding engine oil. Last week, an old Passat showed engine trouble codes, and upon disassembly, we found the connecting rod bearings were scored. Turned out the owner had added 5.5L of oil (standard is 4.7L). Here are three key hazards to note: First, excessive oil pressure can cause front and rear crankshaft oil seals to leak, and oil dripping onto the exhaust pipe will produce smoke. Second, oil foam whipped up by the crankshaft reduces cooling efficiency, making the engine prone to overheating in summer. Third, oil entering the combustion chamber will form carbon deposits. Here's a tip: When there's too much oil, the exhaust will be particularly pungent, and oil droplets may appear at the exhaust pipe outlet.

[LucilleLynn]

Both of my family cars have experienced overfilled engine oil issues. As a novice, I mistakenly believed that adding extra oil would provide better protection, resulting in my CR-V's exhaust emissions exceeding the standard by three times. A senior technician explained: 1. Excessive oil increases moving resistance, potentially causing a 0.5L/100km higher fuel consumption in a 2.0L engine; 2. Foamy oil leads to insufficient lubrication of the camshaft; 3. Incomplete oil scraping by piston rings can cause carbon buildup in the cylinders. When handling this, avoid draining the oil directly as it would waste fresh oil. Instead, purchase a 50ml syringe with an infusion tube from a pharmacy and extract the oil precisely through the dipstick tube. Remember to let it sit for five minutes after extracting 200ml before rechecking, making gradual adjustments for optimal safety.