I started getting a buzzing sound at 2700-3100rpm roughly while driving normally and can't figure out what the cause is. That's what I rev to when changing gears around town so I have to hear it often. Free revving doesn't cause the same noise. I recently had the oil pan off to block off the oil squirters after one broke and had this same sound before that happened. I checked all the main and rod bearing, everything looked great.

I don't have the 2 tie bars under the downpipe installed currently meaning no chance of DP rattle, have a turned down balance shaft(race shaft), and timing is dead on. Rotating assembly is fully balanced along with a Fluidamper. I'm not sure if this noise is due to not having balance shafts but another thought is that I have solid TS driveshaft carrier bushings. Any thoughts?

 

Does anyone else have deleted balance shafts that has input on what the vibrations are like in that RPM range?

 

did you notice the noise after you did the balance shaft?

 

Well, yeah but it was over 4 years from the time the stock engine failed to building this one.

 

because generaly thats where i would start. since you didnt have this issue before then it has to be something that has changed. you made sure that you torqued all the pulleys to spec? possibly a bad pulley bearing? but start off by eliminating one thing at a time.

 

My 2.4LR motor does this - balance shaft deleted. I've also notice the buzzing sound when going over 70 mph. My tuner said it was normal.