I recently had some work done on my blazer. Fuel Pump, alternator, throttle position sensor. Now, whenver the vehicle warms up it makes a humming or buzzing noise coming from the engine. Sounds like an import/drifting car. I have no idea what it is and this occurs while driving, but also when I rev up the engine while in park. The more I press the accelerator the louder it is.
It is a 4.3 litre engine and 2WD.

Thanks

 

maybe a small exhaust leak. i have one and thats kinda what i get

 

It is quite possibly an exhaust leak. As things warm up, leaks can open up due to the materials expanding.

 

If it is an exhaust leak, is that a big deal.