350z Engine Hiss Sound / Burning Smell - Vacuum, Gasket, Coolant Leak? *VIDEO*
 

I've been noticing the smell of something burning through the vents. The smell is more noticeable on the passenger side than the driver side when I have the hood open. While I was inspecting it today I heard a "hiss" sound. Before I have a buddy check it out I thought I'd ask the forum. It sounds like it's coming from the plenum spacer. You can tell as I move the camera closer to the spacer that the hiss gets louder and more isolated: https://www.youtube.com/watch?v=Xa8P...ature=youtu.be

The smell is similar to hot brake pads but since the car isn't moving that's obviously not the cause. Since it's kinda "sweet" I figured it might be coolant leaking and burning on some hot surface. Oil is fine, not burnt and not low.

Figured it out, the valve cover gasket is leaking and oil is hitting the exhaust manifold causing smoke to rise up and then it gets sucked into the vents. Still not sure why it's hissing near the plenum, might be a separate issue. Hasn't thrown any codes and the engine runs just fine.

^^ Just fixed that on my 2003 350z with 130k miles. I replaced the valve cover gaskets, and all is well now. The gaskets were 16 years old. YIKES!

I had the driver side valve cover and gasket replaced in 2016 cause it was leaking at the spark plug gasket (non serviceable). I have a 2004 with 138,000 miles.

I'm going to just replace the whole valve cover on the passenger side since I'm having a shop do the work. According to the forum it's not a matter of if but when these valve covers fail.

Its probably the PCV valve that you hearing. the rubber hose in your video. put a long screwdriver on it (metal end) and hold the plastic end to your ear, should help you identify if its the source.

Actually, I also replaced both the gasket and the valve cover.