Very fast engine noise while parking and loss of power.

Hey Fellow Prius Owners. I have a 2010 Prius and just the other night I was driving for about 30-45min to my destination. While parking, out of no where the ICE began revving up VERY fast and the engine was shaking and felt like it was going to bust. I turned it off right away and waiting for 5min. I then started it back up to continue parking but it still was revving up fast.

After 30min I left and although the noise and heavy revving was gone, I noticed a decrease in power and acceleration. Having it for the past 3 months and driving about almost 6k on it, I've gotten down pulse and glide and remembered at what speeds i can get to in coordination with the HSI meter. But since then i've noticed i would have to press on the gas more to get the speed up as well as the gliding has been a lot shorter as it would jump to the ICE much sooner than usual on my daily route.

I called the dealership this morning and asked if i could bring it in and told them the issue. they emphasized that if the dash doesn't show a check engine light, that they can't (and almost felt as they mean won't) check and diagnose it. Have any of you experienced this? I would love some advice. thanks.

 

if i remember correctly it was 2-3 bars. when in eco mode i used to be able to accelerate pretty good without having to go into the PWR zone of the HSI. Now i have to pretty much push it towards the limit of the PWR zone to get it accelerating at the previous rate.

Any advice for handling this with the service dept at the dealership? how do i get them to just take a look at it? it seems like they don't believe me and believe the computer more because it doesn't show a check engine light.