Having trouble accelerating??

Perfectly normal for the first minute or so after the engine starts. During that time period the system takes the load off of the engine while it warms up and heats the catalytic convertor. The electric motor and battery take the bulk of the load (unless you really mash the accelerator) so it feels a little sluggish. (You can see what's going on if you glance at the Energy display.) Mine is usually warmed-up and ready to go by the time I get from my parking space to the street, so it doesn't cause me any grief.

This is just a quirk of the system. Nothing to worry about. Best practice is to take it easy for the first minute after engine start and then just drive normally.

 

<div class='quotetop'>QUOTE(LisaM @ Sep 10 2007, 12:54 PM) [snapback]510101[/snapback]</div>

Actually, the car doesn't shift, it will always be a continuous tone when accelerating. That is part of the design.

If the acceleration seemed weak, then it was probably just your battery was low (check the Energy screen) and you were being properly only by the (1.5L) gas engine. Again, perfectly normal situation and one that corrects itself within minutes.

Unless you received any alarming messages on the screen or lights on the dash, there shouldn't be anything to worry about. B)

<div class='quotetop'>QUOTE(LisaM @ Sep 10 2007, 01:19 PM) [snapback]510115[/snapback]</div>

There is no need to 'warm up' the car before driving it, the computer will automatically manage when it needs to provide power or warm the engine, etc...

As brick was explaining, the car is trying to also warm the components and therefore work a little harder and can sometimes make a little more noise than a warmed engine, and I don't think it is anything to be concerned about. However, this should be no more than a couple minutes at most, particularly in a California climate.

Anytime you "stomp" the accelerator, it will make a bit of a "scream" as the car's "transmission" tries to catch up to the demand.

If there is indeed a significant change in tone (that is not just environment-related), perhaps it should be investigated...

 

Yup, this no longer sounds normal. The car would feel sluggish if it were trying to charge the battery but it would still make it to 70mph just fine.

How about a stuck parking brake? Are the rear wheels hot after a drive? If you decide to check, BE CAREFUL! Siezed brakes can get a wheel hot enough to burn your hand...you would be able to feel the heat without touching anything. A non-contact thermometer would come in handy but most people don't have one of those lying around.

 

<div class='quotetop'>QUOTE(LisaM @ Sep 10 2007, 11:54 AM) [snapback]510171[/snapback]</div>

Are you certain that you've shifted into "D" and not "B"?

 

Don't be offended: is there any chance that the parking brake is engaged? This would not be the first time...

 

Hi LisaM,

The parking brake is unusual. To be sure you have completely released it, you need to press down, the pull up with your left foot smoothly until your foot no longer is touching the pedal. If you stop anywhere along the release of the pedal, before the pedal is no longer touching your foot, you will have set some braking force.

Additionally, some PC members have found that if the parking brake was not released, and the driver used the full torque of the motor during reversing, it can mal-adjust the brake so that it will not release 100 %. That is, reversing with the brake partially engaged causes the brake to adjust up too tight. If the car does not easily roll backwards with just a little bit of pedal, stop, and recheck that you have fully released the brake. To do this, one resets the brake, then re-releases it.

Have the dealarship put the car on the lift, and reset the rear brakes. With the car on the lift, and the brake off, the wheels should be easy to spin. If not, have the rear brake adjusters reset. Then proper operation of the brake pedal will bring the brake setting into a correct amount of play.

You should not have trouble doing 70 mph. Hell, it should be hard to not do 70 mph in a Prius, due to its smoothness, and quiet nature.

You also need to use the parking brake. Using it resets the rear brake adjustment automatically. If its not properly adjusted, the amount of hydraulic slop in the system will be large, and this could make the switchover from electric to hydraulic braking jerky. Which might cause an unexpected reduction in braking power as one pulls in behind a stationary vehicle.

 

Hmmm... I check back in here, and I agree with others that this no longer sounds normal.

The parking brake does sound like a likely culprit. If you put the car in Drive or Reverse but then not touch the accelerator, does the car crawl as normal? This could be an easy indicator of a non-releasing parking brake...

 

<div class='quotetop'>QUOTE(donee @ Sep 10 2007, 08:06 PM) [snapback]510334[/snapback]</div>

The rear brakes on a U.S. Prius are not adjusted by the parking brake or by braking in reverse. They adjust automatically each time the brake pedal is depressed. It's a slick system. When the parking brake is applied, it presses on the far end of the adjuster to manually engage the brake pads, but that action also precludes any adjustment.

Here is a description and some photos of how it works

Tom

 

I would first suspect it was very hot out and a lot of energy was being consumed by the A/C -and- your traction battery SOC was low. You do not have to "let off" the accelerator pedal just because the engine is screaming. It will take care of itself. If a lot of power is needed for the A/C and for accelerating the engine will scream (it will rev. up to 5000 RPM - some call this redline, but it's more like yellow line - it's used by the system but not exceeded).

Don't be afraid to make it rev. It's designed to do that. It will not damage anything. Use whatever throttle you need. The only time you would let off is in slippery conditions (heavy rain on oily roads, ice, snow). Even then, the only reason to let off is to ensure you don't force the car to save you. Because that also brings up a host of questions and concerns.

 

Do read the two facing pages in the owners manual about strange sounds. It's pretty funny. Basically it says "anything you hear is normal". The other way to interpret it is the Prius is not normal and doesn't sound that way! It has a different drive system and runs differently than most other cars on the road (except other HSD vehicles, such as the Camry hybrid and Altima hybrid).