I'm hearing rattling noise when the transmission is engaged (drive) and it get's louder at higher rpm. previously I did not hear this. There is no noise when I rev engine in park mode.
The gear in normal case would shift as RPM exceeds 1500rpm, but now the gear shifts at 2.5k rpm when it's in constant acceleration, if I speed up and expect sooner gear shift , it does at 3.5k to 5k RPM.
could it be drive belt that is rattling? any transmission digital adjustments.
Please let me know if you need any other information.