Hey guys just wondering if you could help me...my car just started making a loud rumbling sound/feel that vibrates the whole car when I take off in first and second and gets quieter and less vibrating once im cruising in 3rd or higher. It also rumbles and vibrates when im backing up. It also vibrates a little when it's idling and vibrates/rumbles a little more when I rev the engine. The check engine light is not on. It doesn't seem to have lost any power, but it doesn't have a lot of power to begin with. Any suggestions as to what it may be would be very helpful.