For those who have a problem with engine noisy (bunyi enjin bising & kuat), you can try to first investigate where the sound came from. It usually comes from moving parts around belting area accessories, fan or engine internal parts.
If the sound came from outside of the engine like belting area, it probably involves the air cond compressor, belt tensioner or the belt itself.
You can put candles on the belt if the sound of rubbing came from the belt. Or you can put wd40 lubricant on the shaft and moving parts especially on air cond conpressor pulley if the very loud screeching sound came from compressor.
The lubricant really helps remove the annoying sound from any moving parts on engine. Just spray to the parts while engine running.
Sometimes, the noisy sound came from the belt tensioner where the spring has loss its tension and it vibrate. The price for belt tensioner is around rm250 depends on car model.
For those who have a problem with engine noise can discuss here.