general problems of the 2007 Mercedes Benz E350

While driving and changing gears from first to second, at or around 10 - 20 rpm my engine became uncontrollable and jerked sporadically. I could not control the vehicle until it changed into 3rd gear and then began to drive as normal. The car does this repeatedly now until I feel it has become unsafe to drive. The jerking is random so I don't know when to expect it and what to do when it happens. It has caused me to veer off the road occasionally.