A month-long investigation by ABC News has found that Noone's experience is far from unique. BMW and federal safety regulators have received hundreds of similar complaints from owners of 2007 to 2009 BMWs with the powerful N54 twin-turbocharged engine, but little was done to alert drivers. Among the models that could be affected are the twin-turbocharged models of the 135, 335 and 535 series as well as certain Z-4 Roadsters and X-6 SUVs.
Allison Mangot, a former BMW owner, described her experience: "The car started shaking, back-firing. We had no idea what was going on. It's very, very, very scary."
BMW attributes the problem to the high-pressure pump that feeds fuel to the motor. When it fails or falters, the car can suddenly go to a reduced power or what the company calls "limp safety mode."
"When that high-pressure pump on the engine fails, the vehicle goes into what we call a safe mode, which means that you have power steering, power brakes but you don't have as much power and that can be startling for some people," Tom Baloga, BMW of North America's chief engineer, told ABC News.
When pressed about how safe this so-called "limp" or "safe mode" really is -- given the frightening experiences described by some drivers -- Baloga said "it's unfortunate that the failure of the pump caused that feelings and we certainly can sympathize with that. People have different expectations."
And when government regulators at the National Highway Traffic Safety Administration investigated fuel pump-related complaints in 2008, BMW insisted the conditions "do not pose any risk to motor vehicle safety," adding that "despite reduced engine power, we believe that safe vehicle operation is possible."
The NHTSA investigation was closed with a determination that "further investigation of this matter would not be an efficient allocation of agency resources." But closing the investigation "does not constitute a finding by NHTSA that a safety-related defect does not exist," regulators wrote in their report.
Auto safety advocate Clarence Ditlow says he thinks BMW is taking a big gamble.
"This is not a question of whether the pump is defective or not -- it is defective. It's just a question of who pays for it. BMW or the customer, and with the customer, they may pay for it with their life if it fails in a particularly dangerous situation on the highway," he said. "And what they are doing is they're gambling with you, that you won't have an accident when that fuel pump fails, that's not a gamble that you voluntarily agreed to take. That's something that BMW is doing with your vehicle."
But BMW hasn't escaped legal challenge. Hundreds of claims have been brought against the company for fuel pump malfunctions, said lawyers across the country, including a recently filed California class action suit by Kenshaw, Cutter & Ratinoff, LLP.
Most of these legal actions have led to settlements on the condition that BMW drivers sign a confidentiality agreement, plaintiffs' lawyers told ABC News.
"If somebody is in an accident and they're hurt and BMW pays them enough, they sign the gag clause, and we don't hear about it," lemon law attorney Robert Silverman from Kimmel & Silverman, P.C. told ABC News.