I have a 2003 Mazda 6, 5-speed. Whenever I’m driving in higher gear (4th or 5th), the tachometer seems to jump. For instance, if I’m driving at 50mph at 3,000rpm in 5th gear and I want to accelerate to ~65mph, the tachometer seems to jump to 3,5000-4,000rpm, then drop down to 3,000rpm and then slowly increase as I accelerate.
What’s the reason for this random jumping/revving? I don’t think the clutch is going bad or slipping. It only seems to happen in higher gears, even without me shifting–only when I want to accelerate.