I have a 2019 motorhome with a V10. 15K miles. Bought used. Each time I start it, it revs up to about 1,700 rpm then quickly settles down to a normal idle. Everything else in terms of idle, performance, and reliability are perfect. But I am concerned about revving an engine that high when cold and before oil pressure comes up. What could cause this?
Upon start-up, all engines require a period of fast idling when it's cold outside. The engine runs rich (more fuel than air) to compensate, and for a period until optimum operating temperature is reached, then it returns to "normal" (14.7 parts air to one part fuel). The engine will continue doing this past its high idle period until operating temperature is reached. My 2017 Mustang uses a bit more gas for 10 minutes or so, when it's cold. It also won't respond quite the same when it's in warm-up mode vs operating temperature. I usually have my fuel consumption indicator in the multi-sceen thing on instantaneous fuel consumption, the engine is not nearly as fuel efficient when it is cold. It's normal.
