On July 14 2014, was driving my new 2014 MDX. Suddenly heard a noise like a flat tire. I pulled over to the shoulder and checked the tires. Didn't see any flat. Checked the tire gauge and all reading good. Continued going where I had to go and the noise came back. It sounded like dump, dump, dump. The noises come and go at various speeds. Got back home and removed the spire tire, might be loose. Drove around the block and still heard the noise again. It?S getting dark and the following day was raining. Finally got good weather. Decided to move the car into the driveway and look under the car. As I was looking I could see the left rear axle boot was twisted and grease bleeding out. I decided to crawl under the car and saw the whole differential was loose. I could shake the unit. As I look closer, I could see 3 bolts missing and 1 barely holding the differential on the chasse. I called Acura service and told them about my problem and was told to bring it in. Called roadside service and had them put it on a flatbed. The dealer is replacing the left axle and bolts. I hope nothing else will come loose and this didn't damage anything else.

- Bronx, NY, USA

This is the fourth incident of unintended engine revving with this vehicle. This fourth incident occurred at 7121 miles. Was in "reverse, " positioning the vehicle to pull into a parking space. The engine suddenly accelerated while I was in "reverse" and my foot on the brake pedal. Had to firmly press on the brake pedal to hold the car from running into people and other vehicles behind our vehicle. Shifted into "neutral". the engine sounded like one third of full throttle. I pressed on the gas pedal and the engine returned to idle. My wife was with me during this incident. She was with me in the vehicle during three of these four similar incidents.

- Goodyear, AZ, USA

This is the second incident of unintended engine revving with this vehicle. This second incident occurred at approximately 4500 miles. Was pulling out of a parking space in "reverse" and came to a complete stop with my foot firmly on the brake pedal when, in an instant, the vehicle unexpectedly revved up while I was still holding the brake pedal firmly and the vehicle was still in "reverse". alarmed, I immediately put the car into "park". the transition into "park" was not smooth and the engine RPM went even higher. It sounded like one third of full throttle. My wife was in the vehicle with me. Once in "park", we put down the windows to hear how loud the engine was revving. Still in "park", I asked my wife to watch me step on and off the brake pedal at least three times, but the engine did not return to idle. I then kicked the accelerator pedal and the engine returned to normal idle. Acura client relations had a "field representative" check my vehicle. For the second time, Acura is claiming that no problem can be found with our vehicle.

- Goodyear, AZ, USA

The contact owns a 2014 Acura MDX. The contact stated that while parked, another vehicle slightly bumped the contact's vehicle and caused it to roll away in reverse and down a hill. The contact's vehicle then crashed into another vehicle. There were no injuries and a police report was not filed. The vehicle was not inspected or repaired. The manufacturer was notified of the failure. The failure mileage was 2,000.

- Salt Lake City, UT, USA

Yesterday, after backing up, stepping on the brake pedal and coming to a complete stop, shifted into "park" with my foot still on the brake pedal. The engine unexpectedly revved up to what sounded like full throttle! I pushed the ignition button to stop the engine. After this one incident, the car has functioned normally.

- Goodyear, AZ, USA