Purchased a "certified" BMW 1997 740il in 11/02 with 69,000 miles. In January I noticed a "tin can" popping sound from the rear of the vehicle and a vacuum like sound when opening the gas cap to fuel. I noticed that the driver side gas tank had a dent in it although I had not hit anything. I took the vehicle to john roberts BMW in dallas. The service advisor told me that they had never had any complaints resembling mine and that I must have struck something to damage the tank. About one month later the tank began to leak and basically imploded from vacuum pressure. I posted my experience on several web sites and received over 20 responses from owners who had the same problem. One of these people sent me a technical bulletin from BMW to its dealers describing the problem as a fuel tank vent which would become stopped up and cause the fuel tank to implode. I went back to the dealer but by this time my vehicle was one month out of warranty. I believe this defect is a potentially deadly hazard and could have easily resulted in an explosion or fire.

- Flower Mound, TX, USA