One problem related to loud engine noise has been reported for the 2005 Nissan Armada. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Nissan Armada based on all problems reported for the 2005 Armada.
Problem with car accelerating spontaneously when brake booster sensor fails at random times. Initial problem with brake peddle going soft and the anti-lock braking system gets activated when braking trying to do standard braking. The brake light turns on, the peddle goes to the floor, brakes are not normal and very touchy and the car shudders viciously to a stop while. Loud noise is scary while brakes not firing in the usual peddle position and feel like mush. Now in January a new situation started occurring when the brake booster would fail is that the Armada would also accelerate the engine on pressing the brake. I went to stop my Armada's and the engine surged its rpms while the anti-lock relays were firing. I stood on the brake peddle with my every muscle in my body to try to get the Nissan Armada to stop. I could not shift the car into neutral because the shifting lock seemed to engaged. I ended up turning off the engine and was able to stop. I called Nissan America to report this issue. Also stopped by the local Nissan dealership and service manage informed me that the braking issue was caused by the delta sensor in the brake booster and was a know issue but that this was the first time he heard about the spontaneous acceleration when applying the brakes at low speed and that he only had heard about the spontaneous acceleration when applying the brakes at higher speeds. He said this was caused also by the delta sensor in the brake booster. I think I understood him in saying that when this sensor fails it allows the booster to inject air into the intake that causes the car to accelerate. I replaced my brake booster yesterday to find today that my Armada has the same deadly issue! please have Nissan fix this known safety issue!.