Hello guys,

I have an issue that doesn't occur all the time. I've brought it to dealer but they can't replicate the issue, and now that I am out of warranty, I don't want to take the risk and spend money when it doesn't happen all the tie.

Sometimes, when I start the car and start driving, the engine makes a buzzing noise that gets louder as I accelerate on lower speeds. It goes away after about 15 seconds, and won't come back for the remainder of the trip.

This issue has been happening for a while now, but it doesn't always happen. I've also noticed my MPG dropping recently, but that can be attributed to the winter gas.

Does anyone know what the issue could be? Could it be a bad PCV valve? I heard that it can sometimes make a buzzing noise. It actually sounds extremely similiar to this in the video, even though it is on a Lancer. That buzzing noise really drives me nuts when it occurs.

on most of my old cars when i had buzzing sound it turned out to be a loose/rusted heat shields on the cats or manifolds

The problem is, I've already removed all my heatshields from my cats cuz they were all rusted out...so the problem has to do with something else...