My 2018 Mercedes-Benz GLA250 from almost day one will surge when shifting from first to second and from second to third after that it’s smooth as silk. It is an intermittent problem. It will surge for a few stop lights then it will be smooth for several days or weeks until it will happen again. I had the car looked at right after we first got the car and the maintenance shop said it couldn’t duplicate the problem and it drove like any other GLA. They said it may be the “adaptive transmission just adjusting to the way we drive”. Well, it’s been a year I’ve put 3,100 miles on the car and it hasn’t “adapted”. As a matter of fact, it gets downright scary at times when making a left turn when I get a green arrow and it doesn’t go. Then just as the light turns to flashing yellow and the opposing traffic gets a green light the car will jerk three times before it decides to engage and off it goes. I’ve scheduled the car to go in for an annual service on Monday and I’ve told them they are to fix the transmission and there will be no “cannot duplicates” this time. That being said, has anyone had a problem like this before or know what could cause this to problem?
If its serious,the warranty should cover it.
No experience with your car, but that’s a common symptom for a faulty conventional automatic transmission. There are clutches and bands inside the transmission that are wearing parts. The more they wear the more trouble they have engaging the gears. It’s also possible there’s nothing wrong with the clutches and bands. Instead the hydraulic fluid pressure inside the transmission isn’t high enough to develop the required force to effect a swift engagement. Given this car is youthful, clutch and band wear is less likely, and most likely the problem is the hydraulics. A shop can measure the hydraulic pressure at various test ports, that’s probably where to start. As mentioned above this would generally be covered under warranty for a 2018 model. they’d probably start simply by checking the transmission fluid level.
Has it become common enough to happen on demand? Take the dealer mechanic with you and show them. This sounds anything but normal. Also get it in writing every time you take it in.