keith Report post Posted August 2, 2022 I have a 2019 fusion platinum hybrid 40k miles. I was driving from Seattle to Arizona. My wife. Son and myself. All of us together is about 500lbs plus a full trunk The car would start making a harmonic sound that vibrated through the body going up steep inclines. I don't recall anything else happening. But the sound wow it was annoyingly loud. Anybody have a idea? Is this car toying with our lives? Quote Share this post Link to post Share on other sites
Cobra348 Report post Posted August 2, 2022 Did it fade and/or go away as you went downhill or slowed down? I had a harmonic hum on my '17 FFH that gained/faded as speed changed. Turned out to be a loose belly panel. Refastening it fixed everything. Quote Share this post Link to post Share on other sites
Aphex242 Report post Posted July 1, 2023 For the record, this EXACT same thing happened to me a few times on a 300 mile drive (each direction). Sometimes it was ridiculously loud, like almost hurt your ears loud. At first I thought it was another car or something. Then I thought it might be the way my new tires were interacting with road grooves or something. But then I realized it only happened on inclines when the engine was straining. It's almost like the entire car becomes a bell and is vibrating a sound. High pitched (but not overly), comes on steadily until it hits a peak, and then lets up when the engine relaxes. No other symptoms. No loss in power, no real vibrations or anything - just a freaky sound. Sometimes it would be louder than others. And again it happened maybe 3 times each way - it's not a common thing. Anyway maybe this will help someone else, or if other people see this we can try to isolate what's going on. I have a 2019 Energi. Quote Share this post Link to post Share on other sites
