TORSVT6,
That 4000 rpm rev with clutch disengaged may be the classic problem called "throttle hang". Check the FAQ section on "Common Problems/Complaints" for this issue. A less likely cause might be a stuck Idle Air Control (IAC) valve also discussed in the same FAQ section. Both possibilities are easy to handle.
My recommendation on the oil accumulator is due to Contours having the problem of oil starvation when performing prolonged, hard right turns with the engine running at higher revolutions. As a previous post showed, Jack Roush found that only ~ 1/2 quart of oil remains in the pan at 5000 rpm. Part of the problem is also that the oil doesn't drain back into the pan fast enough on the 2.5 L Duratec. The oil pan baffling apparently is not well designed and the remains get shoved away from the pickup on the hard right turn. Thus, filling to ~ 6.3 quarts is one good, cheap way to prevent oil starvation. Ford did redesign the oil pan/baffling system in the late 2000(?) model year but the general concensus on the CEG board appears to be "It doesn't look to be any better or any worse". There is also a modified oil pan/baffling system from Mirko Racing but I don't know any more about that.
The Oil Accumulator is a spring-loaded piston/cylinder unit that is plumbed into the oil system. It retains 1-2 quarts of additional oil and delivers that to the system when a sensor detects low oil pressure. Not a cheap mod compared to just running more oil in the oil pan and it seems like not too many CEG'ers do this mod. I haven't done it yet only because the money isn't available yet.
Keep searching & reading; there's lots of good stuff here.
Dave Keller
1995 Contour SE
1999 Contour SVT
