'03 H6 VDC - odd sound from rear at warm start- help!

subaru
outback

#1

Never happens w/ cold engine. But drive a good bit, get very warm. Park/turn off for an errand in a store and a sound will appear soon after re-starting.



A gurgly-grumbly, slight rubbing distinctly in the wagons rear.



Finally I jumped out to hear close-up and it’s absolutely from the rear undercarriage, it’s mechanical and decidedly less gurgly sounding when outside. Sound only lasts 10 seconds and then disappears. It has the sound of something cycling thru and slowly ebbs away.



It is not the VDC self-checking; my sound only happens when parked. Only once did it seem to happen on a downgrade slope, inching down exit ramp, after having been parked.



Finally to the mechanic and they diag. fuel pump damage & need to replace it. They showed me the pump and admitted that they expected to see the metal band btw the top and bottom plastic compartments of the pump to be damaged. And yet, it wasn’t.



But they seemed convinced that was the fix; because apparently, the old fuel pump tested at 15 PSI less than it should. Unfortunately, I still hear the sound.



I’m turning to fellow drivers to see if any of you have experienced this sound! This is a low miles car, 18k.


#2

The fuel pump would have been my first suspect also.
Since the fuel pump was apparently not the cause, then my next two suspects would be:

A bad purge valve in the evaporative emissions system, or possibly a different problem in the evap system.
A bad “jet pump”.
Because the gas tank of this model looks sort of like saddle bags hanging over each side of the driveshaft, there is a “jet type pump” designed to equalize the amount of gas in each side of the tank. Even though I have never heard of one of these pumps failing, it is possible that you are hearing its death knell.

You may need to take the car to a dealership if the mechanic is not really familiar with Subarus.