Go to fuel station that have service bay. Ask mechanic to inspect exhaust manifold leak from down when you give gas at 3500 rpm. I am 90% sure its exhaust leak and partial smell is passing thru the floor or firewall area.
Check for the exhaust when the engine is off just with a finger see if it is oily then you will know where the Engine oil is going and this could be happening due to either the valve seals,Or PVC valve could be defected.
i have a wiper which gets stuck in between when i start it . the wipers are good but i think the motor is the issue
how can i make sure that the wiper goes till the end