What Causes Increased Noise After Car Maintenance?

[DeCassidy]

There are three main reasons for increased noise after car maintenance: 1. Different engine oil used: This is the most common scenario. "Different oil" primarily refers to changes in oil viscosity grade or brand. If the oil viscosity grade differs, the internal resistance generated will vary, naturally leading to altered engine noise characteristics. Switching to higher viscosity oil may increase idle noise, but noise typically stabilizes at higher RPMs. 2. Overfilled engine oil: This occurs when oil level exceeds the maximum mark on the dipstick. Excess oil should be drained as overfilling increases engine load, reduces fuel efficiency, potentially amplifies engine noise, and diminishes power output. 3. Incomplete old oil drainage: Though less frequent, this possibility shouldn't be excluded. Residual old oil mixing with fresh oil can cause increased engine noise.

[DiEleanor]

A while ago, my car also developed increased noise after maintenance, and I think it might be related to a few common causes. If the wrong viscosity or grade of engine oil is used during an oil change, the oil's flow and lubrication effectiveness can be compromised, leading to increased internal engine friction and noticeably louder noise. Additionally, if the air filter reinstalled during maintenance isn’t properly seated or sealed, restricted airflow can produce extra hissing sounds. More notably, loose suspension bolts or other chassis components can cause creaking noises while driving, posing safety risks. During one of my follow-up checks, it turned out to be an oil issue—switching to the right type resolved it. In short, I recommend going back to the service shop for inspection as soon as possible; don’t overlook minor issues that could affect driving safety.

[VonNolan]

I've driven cars for many years and often encountered increased noise after maintenance, mostly due to improper oil changes. If the technician used oil that doesn't meet specifications or the quantity was incorrect, low viscosity reduces engine resistance but leads to insufficient lubrication, causing metal parts to rub and produce a buzzing sound. Also, if the air filter isn't properly aligned during installation, restricted airflow makes the engine work harder. Sometimes, after replacing the belt, improper tension adjustment can cause slippage, resulting in a clattering noise. I recall last time it was caused by using the wrong oil grade, which was resolved only after switching back to the factory-recommended type. Such issues should be addressed promptly to avoid long-term wear on critical components or even breakdowns. It's best to revisit the original service center with maintenance records—don't hesitate for safety's sake.

[VonElijah]

As someone who frequently drives long distances, I highly value a quiet car. If the noise increases after maintenance, first consider whether the wrong type or amount of engine oil was added. Next, check if the air filter is misaligned, affecting airflow. If the belt was replaced but is too tight or loose, it can also cause unusual noises. Additionally, if chassis screws were loosened during maintenance but not properly tightened, the suspension may produce noticeable creaking on bumpy roads. It's advisable to perform simple DIY checks on oil levels and belt tension, and if the issue persists, return for repairs. In short, don't delay as it may harm the car.