What Causes Abnormal Noise When Accelerating After Vehicle Undercarriage Impact?
2 Answers
The reasons for abnormal noise when accelerating after vehicle undercarriage impact include: deformed floor panel contacting the transmission skid plate or the transmission itself. The solution is to restore the deformed parts or place foam pads between the panel and the engine/transmission contact points. Vehicle Undercarriage Impact: Undercarriage impact refers to when a car's chassis hits the ground or protruding objects like stones during driving. Since there are many vulnerable components under the vehicle, contact with hard stone surfaces may cause scratches. Additionally, the engine/transmission oil pan is extremely prone to cracking during undercarriage impacts, leading to oil leakage. Acceleration Abnormal Noise: Abnormal noise during acceleration could be caused by engine knocking or friction between lubricated valves/guides and hydraulic lifters. Applying lubricant between the hood hinge and sliding track can eliminate this noise.
Last time when my friend's car scraped the bottom, it also had strange noises during acceleration. When I helped him check, I found that the underbody shield was deformed. The metal shield was rubbing against the exhaust pipe or transmission housing, causing very noticeable resonance during hard acceleration. Another possibility is that the exhaust hanger came off, leaving the exhaust pipe hanging and hitting the frame. If there's a metal scraping sound, it's most likely due to the deformed shield, which can be fixed by simply prying it back into place. However, pay special attention to whether there are any signs of oil leakage from the oil pan or transmission housing. I've encountered cases where the shield dented the oil pan, causing engine oil to leak. If you're unsure, the safest thing to do is to get under the car and take a video to show to the repair shop.
