What Causes Increased Engine Noise After an Oil Change?
2 Answers
The reason for increased engine noise after an oil change is either excessive oil filling or inappropriate oil viscosity. Excessive oil filling leading to increased engine noise: Excessive oil filling increases the resistance generated by the crankshaft rotation, reducing engine power and altering the air-fuel ratio in the combustion chamber, which raises the likelihood of knocking and consequently increases noise. Inappropriate oil viscosity leading to increased engine noise: When new oil is added, the engine may not immediately adapt to the oil's viscosity, potentially causing higher RPMs and resulting in increased engine noise. A break-in period is usually required for the engine to adjust, after which the noise should normalize. If the oil viscosity is too low, insufficient lubrication can cause wear and abnormal noises in engine components. Conversely, if the oil viscosity is too high, it can place excessive load on the engine, also leading to noise.
I just went through this a couple of days ago. Right after the oil change, I noticed the engine was roaring much louder than usual, which really startled me. Upon reflection, it might be because they used the wrong oil grade – my car recommends 5W-30, but the mechanic might have mistakenly added 10W-40, which is thicker and provides poorer lubrication, increasing friction and noise. Also, overfilling the oil (shown above the dipstick’s max line) can cause foaming and strange noises, while a loosely installed or leaking oil filter is another common culprit. Lesson learned: Always double-check the service order against the owner’s manual before an oil change to ensure the correct brand and specs. After maintenance, verify the oil level is within the normal range. If loud noises come with vibrations or power loss, don’t delay—visit a professional shop immediately to prevent engine damage. Regularly monitor oil color changes and stick to scheduled maintenance to avoid future issues.
