What Causes Abnormal Noises During Cold Engine Start?
4 Answers
Here are several reasons why abnormal noises may occur during a cold engine start: 1. Inappropriate engine oil. If the oil viscosity is too high, it can lead to insufficient lubrication during engine operation, causing friction and resulting in abnormal noises. Many car owners experience this issue after switching to different oil during maintenance. 2. Improper engine belt tension. If the belt tension is insufficient, it can produce a sharp squeaking noise, which sounds particularly unpleasant. 3. Poor fuel quality or incorrect octane rating. When using low-quality fuel or fuel with an inappropriate octane rating, the combustion process inside the engine deteriorates, causing severe vibrations and noise. 4. External engine-related noises. If the engine mounting or interconnected external components become loose, they can also lead to abnormal noises.
I've encountered the issue of engine cold start noises in many cars over the years, from my youth till now getting older. The main reason is still the engine oil - in cold weather, the oil becomes thicker, flows slower, and causes more friction between components, resulting in that clunking sound. The belt is another common problem; when temperatures drop, the rubber contracts, making it prone to looseness or slippage noises. I remember one winter when my car made squeaking sounds upon cold starts, and switching to lower viscosity oil fixed it. Another possible cause could be aging parts, like worn tensioners or bearings, where metal contraction during cold starts makes the noises more pronounced. I recommend regularly checking belt conditions, using seasonally appropriate oil, especially getting a maintenance check before northern winters. Letting the engine warm up for 30 seconds to a minute after starting can significantly reduce these noises. If left unattended long-term, accumulated wear can make repairs much more expensive.
I'm so annoyed by the cold start noise. Like my old car, it creaks when starting on winter mornings. I asked a mechanic, who said it could be caused by aging belts or a loose tensioner. The rubber gets stiff and uncooperative when the temperature is too low. Using the wrong engine oil might also be an issue, like if the viscosity is too high, causing poor flow and friction noise. It's best to try switching to full synthetic oil for better results. Don't rush to step on the gas when starting; let it warm up for a while to reduce the noise. If it's due to worn parts like roller friction, get it fixed early to avoid breaking down on the road. In short, if you hear unusual noises, get it checked promptly. Spending a little money now saves a lot of hassle, and delaying repairs could double the cost, which would really hurt.
I think engine cold start noises mostly come from loose belts or oil issues. Belts shrink and harden in cold temperatures, making them prone to slipping and noise. High-viscosity oil with poor flow increases component friction. Worn parts like tensioners can also cause noise during cold starts. It's recommended to check belt tension and replace if necessary. Using seasonally appropriate oil can effectively reduce noise. Don't ignore these issues—early repairs can prevent more serious damage.
