What to Do When the Engine Makes Loud Noises After Starting the Car?

[DeAmy]

Solutions for loud engine noises after starting the car are as follows: 1. Engine mount rubber aging or loosening. The engine mount rubber is a rubber block between the engine and the car frame. Solution: Tighten or replace the engine mount rubber. 2. Improper use of engine oil. If the viscosity of the engine oil does not match the engine, it can easily cause carbon buildup, leading to increased engine noise. Solution: Use the engine oil grade specified in the car manual and avoid mixing different brands of engine oil. 3. Engine misfire. An engine misfire means one or more cylinders are not working properly. Solution: Check the condition of each ignition coil and spark plug in the cylinders.

[MilaMarie]

I just encountered this issue last week - the engine suddenly roared like a tractor during startup. Scared, I immediately turned off the AC and shut down the engine. First checked the dipstick and found the oil level normal but the color turned black. Remembering my last maintenance was half a year ago, it might be caused by carbon buildup. Then I traced the sound source and found sharp noises coming from near the belt. Pressing the belt with fingers felt slightly loose in tension. But I dared not adjust it myself, so directly contacted the 4S shop to tow the car away. The mechanic later diagnosed it as aging and cracked alternator belt with worn tensioner pulley. After replacing all parts, it became quiet immediately. The advice is: never delay when abnormal noises occur, as minor issues can develop into major failures.

[EvelynFitz]

To diagnose engine noises, first identify the sound type. A metal scraping noise may indicate a slipping alternator belt, a clunking sound often points to bearing issues, while a gurgling noise is common in exhaust systems. I usually perform three checks: open the hood after starting to pinpoint the noise location, inspect belt tension and cracks when the engine is cold, and check for blue smoke from the exhaust pipe after warming up. Last time my old car made a ticking sound - after thorough inspection, it turned out to be excessive valve clearance that was fixed with adjustment. If the noise worsens at idle, it's likely due to worn engine mounts. However, with modern cars having complex electronics, it's safest not to disassemble components yourself. Instead, record a video with your phone to show the mechanic.

[VonLaila]

Never ignore abnormal startup noises, I learned this the hard way. Last winter, I heard a loud clanking sound when starting my car in the morning but ignored it due to work urgency. The engine suddenly stalled halfway. The tow truck mechanic said the connecting rod bearings were damaged, costing over 8,000 RMB in repairs. Now I immediately shut off the engine at any unusual sound. First check the dashboard for warning lights, then feel if the engine vibration is abnormally strong. Metallic scraping could indicate timing chain issues; bubbling sounds may suggest coolant leaks. If uncertain, call your insurer's free towing service—safety always comes first.