What problems can a dent in the gas tank cause? I have a hand size dent on the rear right side of the tank. I was wondering if this might be the reason for my car blowing steam or white smoke at idle in the morning. And when I first put on the accelerator in the morning, the car feels like its surging. In other words I accelerate and the car doesnt go as fast as I'm pushing the accelerator. Then all of a sudden it picks up like it got a gulp of gas. After that its fine and wont smoke at idle. I would do some tests on my vehicle but I'm not knowledgeable about these things. Is there a link to step by step(pics too) instructions on engine testing?