Back from the dead...

What is your guys rattle\buzzing status as of now?

 

When the engine is warm, I blip the engine to less than 2k rpm and sometimes it makes a buzz/rattle noise.

I popped the hood today in my garage and was pulling the throttle cable thing, just blipping the engine and the buzz seems to be coming from the front of the engine. I couldn't identify the exact source. I didn't see anything loose, the intake is fine and it was making the buzz noise before I got the exhaust. It's definitely right around the engine. It only makes the noise at a certain rpm around 1,500rpm or so. When I rev the engine past that rpm range, the buzz goes away.

Any ideas what it might be? It's definitely weird.

 

Maybe your timing chain tensioner is going bad if its coming from the front of the engine. Usually it does it on startup, but if you let it go for a while, it'll do it all the time.

 

Sounds like a crack in the header heatshield. There are 4 bolts in the stock upper shield. Check there.

 

Thanks for the advice. It doesn't make the noise on cold startup and the noise does go away at higher rpm. It seems like that rpm on a hot engine seems to cause something to resonate in the engine bay.

Another thing I forgot to mention is it has made this noise in varying degrees for the last 10k+ miles. I SERIOUSLY doubt it's engine related or else the engine would have gone bye-bye long ago because I track this car and it sees redline dozens of times a week and certainly a couple hundred+ times on track weekends. Oil level is perfect and I use Mobil One.

Anyway, it very well could be a cracked heat shield on the header. Need to fish around a bit more as it's now annoying me a bit more.

 

If you are at TWS on the 6/30-7/1 I will take a listen/look for you. Looke me up if you are there, I have the Sebring Silver S2000 with the Pink Tape

 

Not scheduled for that event, though TWS is my favorite overall track that I've run on. Love that front straight.

I'm not that worried about it, but it's a bit annoying. I'm hardly ever at low rpm though, so I rarely notice the rattle.

 

Just to add my experience, I had a buzz that occurred between 2k-4k rpm. Wasn't that loud on a cold start, but it would get louder as the engine warmed up. I took it into the dealer, and it turned out to be the timing chain tensioner.