[Monkey Wrench]

like in a plumbing system '" water hammer" causes shock waves this rattles your pipes. a good plumber may install a dampener or even just add a T and run a line upward and cap it off, then the air gets stuck inside and does the same, because air can compress, also a plumber will affix rigid lines with the knowledge that even minor flex can cause fatigue as its repeated many times.
they do move. even if you are gentle with taps, there is the valves in your dishwasher and washing machine , they do similar and may be abrupt. a good comparison is your pipes moving because the washing machine is filling and stopping. the weight of water in a pipe is considerable and so if the water is stopped and started , that causes a shock.

In a car. ok it is higher frequency but it still may cause fatigue in the fuel lines, or at least in rigid lines. I believe that's the reason for the short rubber line after the pump and before the rigid lines. The engine of course moves so it needs rubber lines there too. rubber may absorb some shock if the capacity is basically able to change, but the lines are generally quite rigid in a fuel system.

the dampener is not essential to make the car run but some reported some noticeable noise if it is removed.

its easy to ascertain that vibrations come from the pump but there is a little thing here, in general a pump does not cause pressure, it causes flow. an open pump produces no pressure.

Pressure is the resistance to flow and similar for vibrations, the varied resistance to flow by way of the injectors opening and closing is the cause of the vibration.. the argument can be a bit like a chicken and egg theory but that is how it is normally approached in hydraulic theory.


so what can fail on a fuel pressure dampener? well it has no exit, maybe it could get full and become ineffective, I suppose it could leak, I bet that most that are being replaced are just mechanics being thorough and perhaps wanting the cosmetics of a new one. Ive never heard of a failure myself, has anyone else here seen hard evidence of theirs actually failing? the pressure regulator it can fail, if it fails fuel can get through the diaphram and come into the sensing line which should not contain fuel, if you find fuel in that line its a sign the diaphragm has ruptured..

I just replaced the FPR in my ford van with a straight six even though it tested fine and fuel pressure was ok.. this was because replacement is very difficult and I had to remove the giant intake manifold. I basically shotgunned a few parts during a disassembly and reassembly.. I have a few 80's volvos and a ford van, they have bosche fuel injection and no fuel pressure dampener.

my feelings are that a fuel pressure regulator could fail and maybe cause a problem if you were out on a long trip. if it starts to fail it could also confuse you and led you into some other direction before you located the cause.

I personally feel the chances of such an event around the dampener failing are much less likely.

I'm not planning to replace mine, If I did I'd put in an adjustable one , or one from some other car. because ( in my opinion) it's overpriced..

I have in the past posted a link to a spreadsheet showing different makes and models and their fuel rail pressure. I believe that any one would work so long as its designed for the same pressure as the Porsche,or adjustable to that range, and maybe for an engine that is of somewhat comparable size.

the rest is just plumbing. the only reason I'd gravitate to the OEM one is if your car is original and pristine enough for that OEM look, to matter enough to pay the porsche price. many here are in that boat and keep their cars really nice and that is worth something. If you have the wallet for it, go for it ! if not, I'd google fuel dampeners, there is a lot of info on the web.

i'm basically not rich , so its not on my list. If you are, keep the economy flowing ! ;-)