I have 98 Contour Sport 6cyl. I have a problem while I am driving at cruising speeds. It seems like the transmission is wanting to shift to a lower gear. The tachometer will go up 2000 rpms without increasing speed of the vehicle and then within about 5 seconds it will drop back down to normal rpms. When the rpms decrease the engine bucks like it's engaging the transmission. The position of the overdrive or cruise control have no effect on it. I have had the transmission flushed by a Ford dealer and they can't determine the cause of the problem. Please help.
