I've noticed for the second time recently that the gears seem to hold for longer before switching up. Specifically 3rd to 4th and 4th to 5th. Normally, maintaining the same throttle pressure, the revs will rise to somewhere between 1500 & 2000 before switching up. Today 3rd gear held at 3000+ revs! Driving along a flat road so need to hold lower gear. Same for 4th. It gets brought to my attention by the sound of the engine, almost like it is in sport mode, I even look down to check I'm not in sport! Like I say this happened twice recently.
I'm not sure if it's related, by since I had my main thermostat replaced, I think I can hear a knock/clunk sometimes when I think the gears are changing.
Anyone heard of this?