Why does the engine feel weak after switching to Eagle Flag oil?
4 Answers
Reasons for the engine feeling weak after switching to Eagle Flag oil include incorrect oil quantity, oil-engine mismatch, clogged oil filter, and severe carbon buildup. Below are the reasons for the engine feeling weak: Incorrect oil quantity: When changing the car's oil, there is a specified standard. Adding too much oil: The crankshaft requires more effort to rotate, necessitating greater driving force, which can result in sluggish acceleration. Excessive oil can also lead to oil leaking into the combustion chamber, causing rapid oil consumption and engine carbon buildup, which harms the engine. Adding too little oil: Components do not receive sufficient lubrication, reducing power. Check the oil level with the dipstick and fill it to slightly above the middle line. This ensures proper engine lubrication without excessive pressure on the crankshaft. Oil-engine mismatch: Different engines require different oils. If acceleration feels weak after an oil change, it may be due to a mismatch. High viscosity makes crankshaft rotation difficult, while low viscosity means the engine is not suited for the oil, leading to noise. Clogged oil filter and severe carbon buildup: When changing the oil, the oil filter should usually be replaced as well. If the filter is clogged and not replaced in time, oil will bypass through the relief valve, resulting in reduced car power and increased engine wear.
I just finished repairing my car, and it's quite common to experience reduced power after an oil change. There might be a few issues with the Eagle Flag oil you used: first, the viscosity of the oil you chose might be too high, such as using 40 viscosity oil in a car that requires 30, increasing internal engine friction; second, too much oil was added, exceeding the upper limit on the dipstick, increasing the resistance from crankshaft stirring; third, the oil filter wasn't replaced or wasn't installed properly, leading to oil passage blockage; or it could be an issue with the oil quality itself. Additionally, check if the air filter was overlooked during the oil change—if it's too dirty, it can affect air intake. It's recommended to first check the oil level using the dipstick, then test the idle speed. If the speed is normal but acceleration is slow, it's likely an oil issue. Lastly, keep in mind that there's usually a short adaptation period of a few hundred kilometers right after an oil change, which is normal. If the lack of power persists, take it to the repair shop immediately.
After my last oil change, the car also felt sluggish, especially noticeable on the highway. There could be several reasons: if the oil grade you used, like Eagle Flag, isn't up to standard—for example, an older car requires SN grade but you used SL; or the oil type doesn't match the manufacturer's recommendation, like using European-specific oil in a Japanese car; or the old oil wasn't fully drained during the change, mixing with the new oil and creating impurities; also, insufficient oil pump pressure can affect lubrication. Check if the exhaust pipe emits blue smoke, which is a sign of burning oil. It's best to recall the details of the oil change—was the worker's operation not standard, like the oil pan screw not being tightened properly causing a leak? Don't rush into random repairs; the most practical thing is to find a reliable mechanic to read the fault codes with a computer.
Car power issues should be checked step by step. First, confirm if it's truly caused by engine oil: after warming up the car, rev the engine in neutral gear. If the RPM can reach 5,000, engine problems are basically ruled out. Then check the engine oil—inspect the dipstick level, smell for odor (low-quality oil has a burnt smell), and feel the viscosity. There are many counterfeit Eagle Flag oils; I've seen cases where the packaging was genuine but the oil was black. Next, examine related components: whether the oil filter is clogged, if the PCV valve is stuck affecting crankcase pressure, or if the fuel system is misjudged due to insufficient fuel supply. Finally, don't overlook psychological factors—you might be overly sensitive to differences right after an oil change. It's recommended to use original factory oil for a week for comparison, and only proceed with repairs if there's a genuine issue.
