2.0T Harmonic vibration from engine bay

[Stingkia]

At 3,500 miles, started to experience a metallic harmonic vibration from engine bay as 2.0T engine passed through 1700-1800 engine rpms.

I believe I have located the problem ... a thin silver metallic [aluminum] shroud over the exhaust manifold. The shroud is secured by three bolts, but strangely, even when the bolts are tight, it is free-floating. Tried adding washers to tighten the shroud, but there are spacers inserted which prevent the bolts from being tightened on the shroud. Obviously there must be is a reason that the shroud is free-floating. Will inquire at dealership next week, but good luck on them having a clue.

 

[Robs]

That’s to shield the turbo and exhaust manifold heat away from the rest of the engine bay. It ‘floats’ to allow the thermal expansion.

At 3,500 miles, started to experience a metallic harmonic vibration from engine bay as 2.0T engine passed through 1700-1800 engine rpms.

I believe I have located the problem ... a thin silver metallic [aluminum] shroud over the exhaust manifold. The shroud is secured by three bolts, but strangely, even when the bolts are tight, it is free-floating. Tried adding washers to tighten the shroud, but there are spacers inserted which prevent the bolts from being tightened on the shroud. Obviously there must be is a reason that the shroud is free-floating. Will inquire at dealership next week, but good luck on them having a clue.View attachment 15865

 

[MerlintheMad]

I doubt that's the source of the "harmonic", if this is a new development. No idea what you are describing.

 

[Stingkia]

I doubt that's the source of the "harmonic", if this is a new development. No idea what you are describing.

I'm describing a vibrating sound. It occurs when engine revs through 1700-1800 rpms. Pretty sure it is that heat shield vibrating.

 

[MerlintheMad]

I'm describing a vibrating sound. It occurs when engine revs through 1700-1800 rpms. Pretty sure it is that heat shield vibrating.

Why now? Or are you just noticing it now? If you are just noticing it now, then I'd say it's just a quirk.

 

[Stingkia]

Why now? Or are you just noticing it now? If you are just noticing it now, then I'd say it's just a quirk.

No, it's not a quirk. It is a buzz/noise that exhibits for just a moment as you pass thru that rpm range. It just started yesterday. I placed a few very slight bends in the cover today, and will see if that slight mod has any effect tomorrow when I drive it. Will also have another person be under the hood when I run it up to 2000 rpms in idle.

 

[MerlintheMad]

Will also have another person be under the hood when I run it up to 2000 rpms in idle.

Let them run it up, and you get under the hood.