2008 Cayman Engine Noise

[Bster06]

Hi All,

Wondering if anyone here has heard something similar, or can give advice...

Have an 08 Cayman 2.7 5 Speed, 33k miles. Started it this morning (about 1.5 hours ago), and heard something between a "sucking" and a "rattle" as i drove away (no sound at idle). It was a cold morning (~ 30 Degrees F) so I was not immediately alarmed; and figured it would quiet down as the engine warmed.

It did not.

During my commute, I tried some quick and dirty debugging... Sound seems to be localized to the engine, as it persists when revving the engine as the clutch is depressed / car is stopped. On the highway, I noticed that I could modulate the sound with throttle position (under closed throttle, almost no sound, but gets much louder when the engine is under load and throttle is partly open). Sound did not go away after 50 miles of highway driving.

I know this is a vague description; I guess the best way to describe it would be almost a vacuum cleaner (sucking sound) when cruising, crossing over to a rattle / buzz under heavier engine load or higher RPM. I usually dont mind the racket coming from the back seat of my Cayman, but the sound this morning was getting worrisome.

Thanks for any help.

[sp-design]

i am having a similar experience ... my 2006 cayman s (6 speed), 67k miles, has a different noise when the engine is under load in 3rd gear or higher.  if i slow down, and don't downshift, as i accelerate, i hear a rattle / buzz ... usually starting around 2500rpm.  when i am cruising at 3000 / 3500, i don't notice the sound.  i do not notice the sound at idle. 

 

i am wondering if it is a heat shield or something simple.

[Ptech788]

One thing to check is to see if the top engine cover bolts are tight.