What would cause a racing engine sound from a stop ??

Yes but do not charge at more than 4amps.

 

That's commonly called a trickle charge and yes it can be done but.......

unless you only drive very, very short trips, the hybrid system will/should provide an adequate charge to the 12v battery. If your 2007 still has the original factory 12v battery, chances are very good it is dying or nearly dead.

 

Hot climates are bad for batteries, so check the voltage after standing over night preferably with a digital volt meter if not use, the MFD to check the voltage and report back.

 

Search "optima battery" for a better, lower cost replacement but verify voltage before anything before breaking out your wallet.

 

Hi Don,

After reading all of your posts, I am going to share this with you.

The Prius is unlike any other car you have driven in the past. With that said, it is truly a whole different world and realm when operating the machine (your car).

Concerning the engine which is referred to as "ICE" (Internal Combustion Engine), the Prius will do that at different times depending on the SOC (State of Charge) of the "traction battery" (shows on the screens with green, blue, or pink bars depending on the SOC). SOC is a measurement of how much electricity is stored in the battery. Toyota designed the Prius to only utilize 40% to 80% of the traction battery to make the battery last a long time. If you have 8 green bars, you are at 80% charge, the Prius will then spin the engine with the electric motors to bleed off some of the charge. If you have two or one pink or red bars, the engine will run rather than spin with fuel being injected and being burned. The purpose of this is to recharge the battery. The Prius prefers to keep the battery in the blue area. You should notice that when it is blue, unless you press hard on the go pedal (accelorater), you shouldn't hear the engine rev up, but just notice a slight increase in the sound level.

As other's have said in this string, I would concentrate on P&G rather than trying to regenerate the battery to make the battery SOC turn green. Remember that the Prius prefers the blue state, therefore once you reach all green or all pink, the Prius will then start revving the engine as you describe which is normal.

One other thing, I too recommend that you only use 87 octane fuel. I also recommend that you use "Top Tier" fuel brands. The price of top tier is not much more than the cut rate places, and the Prius will perform better as well as give better overall MPG if you stick with top tier fuel.

Here is a link to information concerning "Top Tier" fuel. You should be able to find retailers in your area and wherever you drive as there are many retailers that fit the category.

Top Tier Gasoline

Top Tier Gasoline

I don't think you have a problem with your Prius. I think it is operating as Toyota designed it to. I think what is happening is that in your effort to "demo to my wife how the gentle, loving touch of the breaks as we approach ANY red lights & SSigns", you are actually causing the Prius to rev up the engine to remove the excess charge that you pumped into the battery by using the brakes excessively. There is nothing wrong with using the regenerative brakes, but you can overcharge the battery when doing so.

Like I said at the beginning of this post, the Prius is unlike any other car you have driven in the past. It is a learning experience. Enjoy the ride and the experience.

Ron

 

Well put together.

John.

 

I've had this revving situation once about 2 years ago and it worried me some. I had been driving the car very hard for a good 6 hours in town with the a/c on quite high. I believe the continued starting, stopping over this long period along with the high a/c use might have put too much strain on the HV battery which had protected itself by revving the engine to provide power to the a/c, instead of via the hot HV battery.

I believe this is how it was described to me at the time. There were no error messages or warning lights so I guess the car was happy.

 

The engine does not run the a/c in the Prius. It's run directly off the HV battery, via the inverter of course.

 

Here ya' go:

Toyota Prius: How to Clean the Throttle Body - PriusDIY.com

PriusDIY.com: The Toyota Prius DIY Resource

 

Apart from if the HV battery is overheating where the engine appeared to run it.

 

I can follow the logic but the ICE would be charging the battery and the a/c using the charge. The ICE would not have to work hard to provide 3kw max for the a/c.

 

Don, if you do clean the throttle body be careful that you do not contaminate the MAF (Mass Air Flow Sensor) that is located in the throttle body. If you were to look inside where the air filter is, and look straight down into the engine on the right hand side of the air cleaner assembly, you will see a thing sticking out from the front of the throttle body. It looks like a piece of black plastic and has a hole in the end of it. Within the MAF, there are a couple of wires that sense the air flow while the Prius is running. If you contaminate the MAF, you may have problems with the ICE not starting up properly and start getting the CEL (check engine light) on the dash. Take the time to learn about the MAF on your Prius before you attempt to clean the throttle body.

For what it is worth, unless the throttle plate is sticking and or the engine is not running smoothly, cleaning the throttle body will only help the ICE run smoother and more economically in my opinion. It is basic maintenance for the most part, but it is not something that needs to be worried about. Like I said before, drive it and enjoy it. The only thing you really need to do is change the oil and oil filter's regularly. Air filter occasionally, and cabin filter when it gets dirty. You also want to keep the tires rotated, as well as keep the alignment correct. One other thing is make sure all fluid levels are correct. Simply get into the habit of checking them each time you stop to get fuel. Other than visually looking at all the bottles, and checking the oil level, there really is not much else to check when you fill up.There is info here that is a general guide line that will show you there really is not a lot of maintenance on the Prius until you hit 100,000 miles. The only exception to the 100K thing is if you want to change the transaxle fluid. Many here including myself recommend a fluid change every 60,000 (60K) miles. The only other thing I would add to the list is to keep an eye on the inverter coolant bottle looking for turbulence (flow) in the coolant. That system has a pump that tends to go out over a period of time. When it does, the inverter will overheat and possibly throw a code of P0A93 which will light the CEL (check engine light). It is imperative that you keep that pump going, otherwise you risk an expensive part on the Prius. The inverter is expensive, but the pump is not. As long as you see the turbulence, you can safely say the pump is working.

What services you need and what you don't | PriusChat

Also, read the owner's manual about maintenance. I would only maintain the Prius as is specified in the owner's manual and you should do fine.

Honestly, unless you start getting lights on the dash, there really is not a lot you have to worry about.

Ron

 

Good job Don, enjoy those numbers!