Cars

What’s causing my vehicle’s hood to vibrate?

John Paul, AAA Northeast's Car Doctor, answers a question from a reader who’s dealing with a mysterious hood vibration.

AP Photo/David Zalubowski

Q. I am wondering if you might know how to fix a hood vibration up by my vehicle’s windshield. I hear it, feel it, and see it when driving on the highway at 75 miles per hour. I’ve adjusted the hood bumpers but that hasn’t helped. Any suggestions? 

A. I would start by making sure you have cured any vibrations in the car. The visual shake in the hood could be a result of an out-of-balance tire, a damaged wheel, or could be driveline related. My first step would be to check and rebalance the four tires. 

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Q. I have a 2006 Hyundai Azera that has been sitting outside in the driveway for almost a year.  I had to boost the battery once but didn’t drive it. Now I can’t drive it because the battery is dead again.  Do I need a new battery? 

A. Realistically, after a jump start the battery should have been charged on a battery charger. Depending on the battery condition and the battery charger, this could take six to 24 hours. More than likely after all this time, the battery needs replacement. In addition, the gasoline could have become stale and may cause some drivability issues with the car. Even the brakes could have become rusted after sitting unused for a year. At this point the best thing to do would be to have the car towed to a repair shop so the entire car can be evaluated to make sure it is safe. 

Q. I have a 2018 Buick Encore with  a so-called bumper-to-bumper warranty. I purchased the vehicle used from a dealer in December of 2021 with a 90-day warranty. On or about the 70th day of ownership, and less than 550 miles, I noticed that the passenger-side front bumper was disengaging from the vehicle where the bumper and headlight area merge. I pushed it in, but it soon popped out again. I called the dealer about the problem, and they set me up with an appointment. Eventually they advised me that the estimate to fix would be over $535 and could be more, all of which would be my responsibility. Oddly, the bumper-to-bumper warranty does not cover bumpers. Do I have any recourse? 

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A. The used car bumper-to-bumper warranty typically covers mechanical issues and not body repairs. Buick did issue a technical service bulletin that describes this problem and a repair solution. There was a technical service bulletin issued, but not a recall or warranty extension, so at this point you would be responsible for the repair. That being said, if you purchased the car from a Buick dealer and there shows no previous body repairs, it is worth suggesting that Buick, the dealer, and you split the cost of the repair. 

Q. From day one the auto-on high-beam feature on my 2019 Acura MDX has worked maybe once that I recall. Whenever I bring the car in for service, I mention it to the dealer, and they tell me nothing is wrong and that they’ve adjusted the sensitivity. Any suggestions? Also, I’m having issues with “auto engine idle”. Last time in for service they rebooted the module which has helped, but this still occurs intermittently.

A. The system may be operating normally. The auto high-beam issue has certain criteria for it to work properly. Some of these include white- and red-light sources that are not detected ahead, two or more street lights have not been detected, or vehicle speed above 35 mph. In addition, weather, road conditions, and windshield wiper settings may affect system operation. The idle -stop feature also has certain criteria for proper operation. Some of these include electrical load on the engine (climate control, seat heaters, towing a trailer) as some examples. The system also relies on a fully charged battery. If much of your driving is short distances, the battery may not be fully charged, and the system keeps the engine running to help with electrical demand.  

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John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your car question to [email protected]. Listen to Car Doctor on the radio at 10 a.m. every Saturday on 104.9 FM or online at northshore1049.com.

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