What Causes a Loud Noise When the Engine is Cold?
2 Answers
Engine cold start noise can be caused by a cracked exhaust pipe, worn spark plugs, depleted oil level, or damaged engine bearings. Cracked Exhaust Pipe: If the engine noise is coming from the exhaust pipe, it is highly likely due to a crack in the exhaust pipe, which can be resolved by replacement. Worn Spark Plugs: A high-pitched noise during high-speed engine operation may be caused by worn spark plugs or clogging due to dirt, and can be fixed by replacement. Depleted Oil Level: If the engine noise is very low and deep, it may be due to depleted oil level, which can be resolved by timely refilling. Damaged Engine Bearings: If the engine noise changes with the maximum power RPM, it may be due to damaged engine bearings, which can be fixed by replacement.
Every morning when I start my car, the engine noise is incredibly loud, sounding like a tractor starting up. There are a few main reasons for this: one is that when the engine is cold, the oil hasn't warmed up yet and is as thick as syrup, causing increased friction during operation, which naturally leads to more noise. Another common issue is that the valves or chains become tighter or looser at low temperatures, resulting in a creaking sound every time you start the car. My own old sedan is most noticeable in winter, and after several checks, I found that the noise was caused by aging and slack belts. I recommend first checking the oil condition; if it's been a while, switching to new synthetic oil might help a lot. But if the noise is too loud and accompanied by shaking, it's best to take it to a mechanic to avoid small problems turning into big ones, which could affect driving safety. In any case, this kind of noise is common in many cars, and if it disappears after warming up for a few minutes, it's usually nothing to worry about.
