Not sure if my problem is the same, but I get a different sound from my front suspension, especially when first driving the car in the morning, and when everything's cool/cold....and more from the right front than the left. It's a loud squeak, rather than a hiss, and occurs with every small bump or dip in the road. I had a similar problem years ago with a Mercury Marquis, where the squeak became so loud it turned heads half a block ahead. At that time, Ford told me it was an expensive fix, so I lived with it a few more weeks, then sold the car.Does your front suspension still hiss when you hit bumps? Like going into a parking lot or driveway. And what did you end up going with?
Since my '03 Malibu has only 110,000 km, (68,500 miles), I'd sure like to know what my problem is.