Today, since it's been a few days the car is not driven, I tuck it for a spin. I decide to make a hard pass in the first three gears in a clear open road with no cars in sight. After I stop in the intersection to turn left for my home, I noticed this weird noise coming from the engine bay. It sounds like this http://www.youtube.com/watch?v=POUT1...eature=related but really low. You can feel a super slight shaking. But when I disengage the clutch to changer gear, the noise and shake goes completely away but while starting to accelerate whit the clutch engaged, it returns again... What can this be?

 

If the noise and vibration goes away with the clutch depressed, its more likely transmission/clutch related.

 

Noise with the clutch engaged will likely be the front main bearing in the transmission. I've had one wear out before, but it wasn't as loud as that piston engine with a spun rod bearing in the video. It would just be a constant droning sound that I'd hear in neutral only.

 

It sounds like that but really low and while accelerating under load(driving), the sounds is close to that.... I will try and verify the clutch/flywheel....