Hi Bro...
IAFM?
That shld b loud "Tak Tak Tak" sound eg like diesel engine (taxi/lorry)...
Can Google for vids in YouTube...
So dun think that fits yr description.
Mayb CVT whine...?
Our CVT sifus shld b able 2confirm if so...

Greeting from JB!
Many car accessories shop here and many car wash centre.. Lol
Many vroom vroom also.
Kthxbye.

tak ade? 
so if wan to add, need to change the car alarm system ?

From what I'm looking at, your car does not have an external fuel regulator at the fuel rail, it's an FLX. It is IAFM+, not IAFM. According to some senior member, IAFM+ were made stronger compare to old IAFM module that always picah

IAFM rosak render the sound "tub tub tub tub tub" from the right side of the intake manifold, where the PURGE VALVE located.


The same car as above, after repaired the rosaked IAFM, only rendered the similar tepet sound like minor "tak tak tak tak tak" sound on the rocker cover.


A more effective way you can identify is:


1) If can hear loud tak tak tak tak tak sound, at this point means the exhaust valve lifter bising, go claim warranty
2) If can hear loud tak tak tak tak tak sound, at this point means the intake valve lifter bising, go claim warranty
3) If can hear loud tub tub tub tub tub sound, at this point means the purge valve sudah koyak, go claim warranty

However, for 1 & 2 is insignificant. Replace or not replace does not really helps to eliminate the noise, its just the way how hydraulic valve lifter works. When enough lubricants, no noise. When not enough lubricant, especially cold start, aircon compressor kicks in, these are the time most car will have loud valve lifter noise. If you think your car is loud, try those Honda B16/B18 series engine, also not forget Plotong Pugra & Wigra 1.8 with 4G93 engine, their valve lifter is much louder than most yellow black diesel taxi.