Assalam o alaikum everyone,
I own a 2001 Vitz. Every morning when I start the engine, its starts and idle smoothly Masha Allah. The problem begins when I put the gear knob in "Drive" and put a little pressure on accelerator pedal. I hear strange sounds from engine (not squeaking, but "phata huwa") until either I put away my foot on pedal or put some more pressure on pedal. I mean it feels like engine is not revving or accelerating smoothly for first two to three minutes. Everything is normal again when blue light (temperature gauge) goes out.
Looking forward to get expert opinion from you people soon.
**EDIT: Vehicle has never been used on CNG. Full time petrol