[WI Salsa Red]

I've noticed at temperatures below about 40 F our '04 ICE revs once or twice when 'shifting'; once it's warmed up, no further problems. Has anyone else noticed this?

Otherwise, smooth sailing and a wonderful vehicle (aside from some of the initial 'check engine light' problems reported by others).

 

[john1701a]

> I've noticed at temperatures below about 40 F our '04 ICE revs once or twice when 'shifting'; once it's warmed up, no further problems.

It's not a problem. Since the transmission is always engaged and never actually shifts, it is impossible to "slip".

What you are actually feeling is purging from the emissions system. It takes advantage of the engine running to perform a cleansing of captured vapor from your previous drive.

With the classic model, the engine would fire up after putting the Prius into park. With the 2004, it instead does the needed "housecleaning" during warm-up on your next drive.

 

[Fredo]

Thanks, I'd noticed that a few times, too. I'd wondered about it, and was going to ask the dealer about it if it kept up. Now I won't worry about it.

 

[john1701a]

The behavior caught me off guard the first time I experienced too.

But since I knew Toyota had eliminated the restart-when-shifting-to-park behavior, which many did not care for, it only made sense that the "housecleaning" routine was now triggered at another time.

I've actually only noticed it 3 times over the last 4,500 miles of winter driving. So having the engine already running and just waiting for a high RPM opportunity really was a good decision. The old behavior was noticed about 50% of the time. Now it is quite rare.

Braking really hard or accelerating aggressively (one step more than briskly) while the engine is still warming up are ways to trigger it.

 

[WI Salsa Red]

That's very helpful to know...thanks.