Guys please do help:

I have an Altis 2003 ride 1.6G automatic. Sometimes i noticed intermittent (on and off ) abnormal sounds coming from the engine or maybe maybe transmission

Initial troubleshooting done:

1. Off air con (still have)
2. Switch to park or neutral (still have)
3. Car is parked (yesterday) still occurred for ten to twenty seconds tapos nawala na.
3. Check oil (oil level is high based on the dipstick but still within limits)
*(Change oil was done 3 weeks ago)

Details:

1. Sound is like the engine or something works harder for ten to twenty seconds tapos mawawala na.
Intermittent problem. AFter the abnormal noise it turns back to normal (normal humming engine noise). I noticed this more on idle to low speeds (since noise is a lot less) than driving in a highway.


Thanks in advance!