I have a 2006 Mazda 6 that ive owned for a year now. It has this random problem tho… when accelerating into 4th gear it makes a horrendous racket like the bottom is falling out of the car or something and sorta jerks. it has been doing this a long time. other than that it drives fine! i have no mechanical knowledge about cars so im totally clueless! this seems to happen when accelerating on an incline.
My guess is that you are lugging the engine when accelerating in 4th gear on an incline. Shift into third gear and you won’t have the problem. I don’t know how many forward speeds your Mazda has, but I think you may be shifting up into 4th at too low a speed.
Does this happen during the shift into 4th or after the shift while running in 4th?
It is a stick shift, right?