High pitched sound.
 

So I have had my 8 for about a month now. Have been completely on top of all maintenance and oil etc.

I am driving the car home from the drive in the other night and apart from the usual engine sound that comes from acceleration, there is also a really high pitched sound. Any thoughts? It has since dissapeared.

Second question, I bring this up because I just started buying this gas and maybe it has something to do with it. Is gas with ethanol in it bad for me?

No CEL's? Was it from the engine or transmission? My guess would be a possible vacuum line, but it is kind of ruled out if it's dissipating on its own. Did you suffer any performance changes? If it has gone away and doesn't seem to have affected performance I wouldn't worry.

As far as using ethanol, I personally wouldn't do it. I use nothing but 93 octane. That's just me. Maybe ethanol is fine, but I'm not chancing it.

That sound is likely the OMP vent hose or elbow fitting on the accordion hose leaking. If so, you will have unfiltered and unmetered air entering the engine, which will not damage the engine in the short-term, but it is definitely not good for the engine in the long-term. I would investigate it and fix it right away. Broken elbow fittings are somewhat common.

I read a couple more posts. It is likely that the sound is just the normal sound that the rotoray makes and I never really hear it because the windows are almost always open.

At what RPM does this occur? Does it reoccur each time you reach that RPM?

Don't take this the wrong way, but this isn't the redline buzzer by chance? There's a high pitched buzzer that goes off around 8000 rpm and higher.

Haha no it's not the redline buzzer. It was happening pretty much any time i went above 6k. I am gonna listen for it today.

Im in the process of investigating some abnormal engine noises myself, what doest this noise sound like?

Does it occur at higher RPMs?

Im hearing a choppy noise at high RPMs after 7K, it sounds almost like something is rattling in my intake manifold, and Ive heard it since I put the K&N junk on my car in 2008 :icon_no2:

LMK. My apologies for the threadjack.