Can anyone let me know if they have an annoying high frequency rattle that seems to kick in around 4,500rpm and dissapears from 6,000rpm onwards, I am wondering if a heatshield is loose or possibly a baffle in the exhaust?

Any ideas?

 

Depends on what your setup is...I have a whistle from the engine bay from 3000-4000rpms from my intake. Nothing else though other than my softtop tray on occasion.

 

If it occurs when not moving, get a friend to help. One revs, one listens.

To aim the hunt, consider whether the noise is related only to rpm, or also affected by speed, or load on the engine, or something else.

I agree that loose sheet metal shields are good candidates. The heat shield between exhaust and battery is large, relatively flat, and supported only on one side. Looks almost designed to resonate. However its singing or buzzing range is usually in a lower rpm range than you report.

There are some exhaust heat shields under the car.

The engine undertray and fender liners are plastic so seem less likely, but most of their fasteners are plastic too and can fail. The wrong combination of missing fasteners might allow plastic to vibrate against metal. I've gotten a rattle that way, but occuring over rough surface rather than at some rpm.

 

I've been searching for a similar noise for the past year or two. The main vertical heat shield has 4 bolts in it which can get loose or fall out. The 4 heat shields going from the exhaust manifold down the exhaust can do the same thing. I actually pulled the one off the manifold off yesterday and found that it had 5 separate cracks in it.

Additionally, I replaced the catalytic converter with a hi-flow one a few months ago. The stock one had the element able to shift, and also had a rattle. I figured the rattle was just a stone that made its way into the clamshell, but I finally managed to get it out, and it turned out to be part of my O2 sensor that had fallen off.

 

Turned out to be one of the heatshields going down the exhaust, 2 bolts had rusted through, removed what was left, installed 2 new bolts and no more noise

Thanks for your input on this good to know there is a wealth of knowledge out there we can tap into