Recently I have an issue with the idle. I have a 2010 Raptor 5.4 with a E Force S/C with 150,000 miles.It starts fine goes into fast idle as it should then settles in around 650 rpm. After a half hour of driving the idle creeps up and eventually stays around 950 rpm (in park). This is very consistent it always idles fine for the first 1/2 hour or so then ends up at 950. There is a little surge at the 650 idle but very little. I assumed I had a vacuum leak and so I sprayed all the usual places looking for the leak then bought a smoke machine but still no luck in finding a vac leak. I also replaced the Tbody including the IAC and TPS and no change. I tested the brake booster and replaced the break check valve as well. I am running out of ideas which leads me to question the S/C. Outside of a gasket leak at the base of the S/C is there any way it could be the culprit?