[ncb639]

I have a 2000 3.8L and it runs like a champ. It gets about the same mpg. It really drinks up the gas in the city. I replaced the isolator bolts and didn't see any difference in mph. The only difference for me was the engine light went off. I get between 19 and 23mpg on the highway and around 300-350 miles a tank in the city. You can convert to km if you like.
I suggest replacing the coil pack and ingition wires and have an assistant turn the steering wheel so you can pin point the swooshing noise you are hearing. My engine also has a lot of oil in the air intake tube but I have 240000 miles on it. Ford also claims that oil in your intake is what causes the isolator bolts to come loose but if you engine light is not on I wouldn't bother with them yet.