2008 Prius - 28 MPG! Need Help!

Discussion in 'Gen 2 Prius Fuel Economy' started by darkgiant, Jan 16, 2013.

  1. darkgiant

    darkgiant Member

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    Hello!

    I was certainly browsing through these forums and the title may jump an eyebrow (or it did for me!) my 2008 Prius is practically averaging 28 MPG (this is when I did my own calculations, as I kept all receipts at every trip I made to the gas station).

    I currently own a 2008 Prius which used to serve as a NYC Taxi Cab, it had retired for over a year and then was used locally (non-taxi). I had bought this car off a good friend of mine, as I was aware that it certainly had a very high mileage for such a young aged car ( currently has 260,000). He had mentioned that there was a problem with the rims (a sign that looks like (!) or something like that) was on. Anyways, I had moved out from NYC all the way to Washington State (I towed the Prius of course) and now I have driven at least 5,000+ miles ever since the move. Just a timeline, I had bought this car in April of 2012, around the summer of 2012 (July, 2012) A red triangular light had turned on. I of course did research and pretty much rebooted the system (manually unplugging the battery). This happen 4 more times throughout the summer, but as the temperatures started to decline, the red triangle light suddenly disappeared I got very curios where I went to a mechanic (who people claim has a strong knowledge in Prius) for a regular front wheel alignment he fixed my car and as well read the codes that the Prius was sending him, claiming that the water pump was not turning on at all, and that the car will run fine in terms of performance, but it will receive the red triangle light again. He changed the tires as well, as I assumed that might help balance off my situation.

    NOW, I apologize for that long story, what I am currently trying to understand is exactly WHY my Prius gets only 28 MPG. I put my foot LIGHTLY on the gas pedal (heck, drivers stick the finger as I take my time to ramp up!) and have maintained this car as if it is my baby (and it really is!) I always try to keep my speed steady and never have it jump board (for example, from 60 mph, all the way to 70 mph in a matter of 30 seconds). After ~250-270 miles, I tend to start getting the blinking one bar light, as I then go fill up gas. My driving path is from Federal Way, Washington, all the way to Bellevue, Washington (I spend 95% of my driving on the freeway, I-5 then I-405). I once took the car out at a night to Seattle, and when I reached the hill, the car just sounded like it was going to give up, only going 12 mph with my foot all the way in the gas pedal!

    Anyways, my questions (sorry!)
    1. I have maintained the car, and with a high mileage, is it normal for a Prius to give me such a low MPG? any other suggestions rather than driving habits to possibly bump it from 28 MPG to possibly 38-40 MPG?
    2. Is it normal for the car to drive VERY slowly when going up a hill?
    3. It also makes a lot of noise at start up and when I do shut it off it continues to make noise (Is this a signal of something?)
    4. Could the water pump be the problem to all this? How hard would it be to replace the part itself by myself? (I know my things about cars, certainly not hybrids! But I am looking forward to this learning curve!)
    Anyways, I think I wrote a lot (or I hope so!), if there are any further questions or information you may need, I can include that in the post.

    Thanks!
     
  2. nh7o

    nh7o Off grid since 1980

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    1. 28 mpg indicates one or more significant problems with the car. They need attention now.
    2. No, see above. It sounds like the inverter coolant pump is not working, and that is causing the inverter to overheat. The control electronics limits the current through the system to protect itself, and that severely limits power to the wheels.
    3. It depends on what "a lot of noise" is. There is a pump that circulates coolant to the storage tank after shutdown, which runs for several seconds. It should be a gentle whine but if it is defective it might sound rough. Those pumps are a problem for high mileage cars, and it could need replacement. But that pump does not cause serious performance issues.
    4. The inverter coolant pump is a *very* common fault in Prius Gen II, and it is subject to a recall by Toyota at the moment. They will replace it for no cost. This pump is *crucial* to performance of the car, and it is very important that you replace it ASAP. There is a potential to damage other more expensive components. There is information on this site on DIY, but I'd let Toyota do it if possible.

    Also your 12V battery is likely bad, as it is more than 5 years old. The (!) icon is the TPMS system telling you the tires are low. Check the owner's manual for that info. Keep the tires to ~40 psi. There may be more problems, but you need to get the DTC's read and listed here so that others can give more advice. It is possible the hybrid battery is near the end of its life as well, but fix the other things first.
     
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  3. Britprius

    Britprius Senior Member

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    NH70 has covered the immediate problems, but another one is choice of tyres.

    Tyre pressures being low will impact MPG but the wrong tyres can easily loose 7 or 8 MPG.

    To sum up a number of items could add up to your MPG loss. Please let us know what tyres are on the car "as much detail as you can eg, make, type, any type number and the pressures you run them at" we may then be able to help more.

    John (Britprius)
     
  4. danboy

    danboy Junior Member

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    Pull the pending codes and post them for us. I also have a high mile 08 but I have managed to stay ahead of issues.
     
  5. darkgiant

    darkgiant Member

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    Wow, amazing in depth answers so fast! I will gather all my information, and look into the inverter pump and see if that may be the little pest.

    Thanks a lot!

    Back to the car, I thought maybe if I put more time onto driving locally to work, that might make a difference - looks like it was not. So anyways, how can I get these "DTC" codes or pending codes? Would I need to go to a toyota dealer and pay a certain amount for this?
     
  6. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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  7. darkgiant

    darkgiant Member

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    Are there any cheaper solutions? Just curios...if not I will see what I can manage to do.In the meantime, I contacted a Toyota Dealer about the inverter pump, sounds like they can have a look at it for free of charge, and as the recall says they will replace it for free of charge. Anyways, I will try that out first.

    Thanks a lot! I am making progress!

    By the way, JimoPalmer, how did you exactly fit that signature bar? is it remotely connected to your Prius? Just curios!
     
  8. nh7o

    nh7o Off grid since 1980

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    If you have a laptop available to use at the car, do a search for "miniVCI" on eBay.
     
  9. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    Fuelly.com is a site that helps you track your mileage, you can enter receipts, texts, smart phone apps, etc. and it will keep a running log of your mileage. They give you signature blocks that updates every tank. If you click on mine you will see quite a bit of detail about my car's history. (Because owners are free to lie, it should not be used as an absolutely factual source. But it offers an alternative to EPA mileage estimates)
     
  10. bobodaclown

    bobodaclown Member

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    You can stop by a local chain auto parts store (autozone, discount autoparts, O'rielies) they will usually pull the codes free.
    I just ordered a "mini VCI" from ebay. I'll let you know how it goes.
     
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