What Causes Abnormal Noises in the Engine Compartment?

3 Answers
Roy
07/29/25 8:52am
Engine compartment abnormal noises may be caused by the following reasons: Abnormal noises in the engine compartment while driving could be due to issues like engine valve noise, piston noise, accessory noise, or even transmission noise and chassis noise. Since there are many potential causes of abnormal noises, an accurate diagnosis cannot be made without inspecting the actual vehicle. Additional Information: Sometimes, abnormal noises are heard from the engine while driving, but when the car is stopped for inspection, the noise does not occur even when the engine is running at the same RPM as when the noise was heard. In such cases, you can loosen the carburetor adjustment screw slightly and then restart the engine to see if the noise reappears, which can help identify its characteristics. If the noise still does not occur, you can try cutting off the fuel supply to a specific cylinder and performing a rapid acceleration test. This may help the noise to reappear and also determine the relationship between the noise and the specific cylinder.
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DiVivian
08/12/25 7:18am
My old car's engine compartment was making a weird clanking noise, which scared me into checking the oil immediately. The most common issue is when the oil level is too low. Insufficient oil leads to poor engine lubrication, causing parts to grind and make noise. Also, using low-quality oil can have the same effect—poor lubrication can cause the timing chain to wear out or loosen, resulting in strange noises. Last time, I had a problem with a stuck oil pump, which disrupted oil supply, making a sound like gears slipping, which was really annoying. It's important to regularly check the oil level, especially before long trips. Using high-quality oil can prevent such issues. If left untreated, a damaged timing chain could cost thousands to replace and might even affect the entire engine's lifespan. Regular maintenance is key—changing the oil yourself isn’t too hard and saves both time and money while avoiding major repairs. If you hear unusual noises, don’t delay—check the oil level and condition or visit a professional shop for diagnosis. Don’t let a small problem turn into a big one—safety first!
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Gwendolyn
10/06/25 2:14am
Over the years of running this auto repair shop, I've often encountered customers complaining about strange noises from the engine compartment, especially those related to engine oil. Most of the time, it's due to a faulty oil pump failing to circulate oil properly, causing internal metal components to grind and squeak. Sometimes, a clogged or leaking oil filter disrupts oil flow, resulting in clunking noises when the engine is under heavy load. Another common culprit is a worn-out timing chain that rattles continuously upon startup. All these issues are related to oil maintenance – regularly checking oil levels and timely top-ups or changes can prevent them. Ignoring these problems not only leads to persistent noises but may also seize components and cause complete engine failure. I recommend having technicians test system pressure with a multimeter during every maintenance service – early detection means minor repairs that can prevent major expenses.
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