that's the sound of something under the rear deck that my rear speakers are mounted on. It's driving me mad!

Anyone have tips on how to remove that whole rear deck to see if I can find the source?

Already pulled both speakers in the past with no luck. Definitely isn't the speakers or their covers buzzing either.

 

Btw... It's coming from the passenger side. Not entirely sure it's not in the space between the rear window and passenger rear quarter window.

Could be the third tail light assembly but haven't looked under the cover and its on pretty snugly..

 

Isn`t there a fuel pump in that corner of the engine bay? If so, could it be that?

 

Fuel filter, yes. Fuel pump is under the gas tank.


Andreas

 

there is only 4 screws holding the rear deck in place. speakers wires can be unplugged and you can pull the entire deck out. at that point the only thing holding it back is the rear seat belts.
but you could pull the deck forward as far as possible and drive around to see if the buzz is more distinct.
there really isn't much back there to buzz except speaker wire, rear window defrost wires, rear wiper assembly.

might be easier to check the 3rd tail light first for a burnt out bulb or loose wire.
or maybe a rear seat belt nut loose and vibrating?

 

Only just the four visible screws hold the deck in place? No clips or anything? So just unscrew and slide it forward...that's all?

It just occurred to me that this is the same side as the wheel well liner that must be partially disassembled to gain access to the tank for oil changes. I've had an oil change recently but my past experience was that when a liner screw hit the sheet-metal, it sounded differently....I think....

Doubtful it's anything from engine bay by the sound of it.

 

I think you are on to something there...
wheel liners can be a pain and create noises.

If it happens above a certain speed and not related to an RPM range while sitting still, this could be it

 

It's definitely RPM sensitive....more like muffler resonance sensitive. My Mille Miglias sound great but do resonate at a certain RPM. Hard to replicate the vibration unless the engine is under load. Will check the wheel well liner and pull the rear deck forward today to see what's what....

 

since it's rpm sensitive you should do a quick check of all the muffler and cat straps, supports and connections.
the lower bar of the muffler support bracket is held in place by a bolt just above the heat exchanger. if the bolt is loose the bracket will vibrate like a tuning fork at certain rpm's and make an annoying noise.

 

+993
Drove me crazy after I did the engine drop. Took me months before I found it.

 

Problem Solved!

So after taking a break and not using the car much and having spent some time a few weeks ago pulling apart the rear deck, 3rd light bar outside, and generally being convinced it wasn't from those sources, I finally decided to pursue the idea of hunting in the wheel well. I had not seen the last two posts until today but kind of wish I had.

The culprit was the heat shield just above the muffler that is attached to the sheet metal. The front of this shield is held in place by a screw that goes through the center of the rear wheel well liner/arch. I pulled the liner out after banging on it to see if the screws above holding the two wheel well arches were tapping on the sheet metal but they were not. When I had the arches removed I banged on the heat shield and I had my suspect! I simply bent the shield downward a bit so it wouldn't make any contact with the body sheet metal above it and then reassembled everything making sure the heat shield wasn't going to touch the sheet metal above and DONE!

I am 99% certain this problem was caused by the mechanic that worked on my car at Beverly Hills Porsche a few months ago. I went in after the flapper box by the exhaust had come loose backing into a parking lot wheel stop. Thats one for the "keep engine tray on" crowd. While there, I suggested that they go ahead a change the oil. BIG MISTAKE!!!!! They broke my oil filler's vacuum cleaner hose looking thingy ($25 bucks at dealer cost). I raised some hell but charging me their cost was the best I could do. I'm sure they broke it moving too quickly and jamming the oil filler hose down in there and breaking it. I'm also pretty sure that the mechanic pulled BOTH halves of the wheel well liner to change the oil tank filter when he really didn't need to. I never have when I do oil changes myself. Convinced that he threw everything back together quickly, no doubt banging the liners back in place rather than carefully reinstalling and in the process knocked the heat shield backwards and upwards. Thats all it would have taken to bend it enough to hit the sheet metal.

I'm NEVER taking my car back there again or any other mechanic that I don't know. Me or RS Enterprises in Ventura. Only costs me one free AAA flatbed tow truck ride if I don't have time to drive it there and WELL worth it!