I bought mitsubishi mirage 2014 in April [imported from Japan; its Thailand made]. Recently I heard very minor noise and a small jerk on accelerator when car is driven from cold state. Its always heard at fixed speed of 40 kmph and just once; till the car is parked again. Even if I keep driving it for one hour and car stops in between accelerates from speed zero many times then neither I hear any sound nor I observed any jerk on accelerator. When I park car for 10 minutes and run again then same noise is heard and impact on accelerator.
Once while using reverse gear I felt minor grinding impact on accelerator in inclined drive. Any suggestions? What can it be. And what is making noise heard only at fix speed. Is it cvt or throttle. Cvt fluid is as clean as it can be. Car is just 26k driven. I usually don't drive more than 80 kmph speed.