salam brothers,
I bought a 2007 HR15de (1.5 L) wingroad recently , it drove good for a week after that the car started to lose power while driving in D and D1 , for example if I climb up the ramp of my apartment it takes full throttle in D1 and it feels like it will stall at any moment and I have to offload my family just to bring it out of the apartment but when I reverse it out of the apartment, it drives without any problem
A mechanic said the problem is with the transmission as the engine is 100% although it has a slight knocking noise which he said is the noise of the "dabbu" and is not the reason of the said problem. He suggested me to change the ATF first then go to other routes if it does not work.
Please note that transmission fluid smells like it burned back in the 1950's.
Please adivse what shoud be done in this case