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101k now / Never done any maintenence, now i'm getting poor mpg. What do I do?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by 240sxer, Apr 5, 2010.

  1. edthefox5

    edthefox5 Senior Member

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    Did you replace the trans fluid yet??

    Also Just as a lark check out my post "VVT Filter Poor MPG's ? " in
    the maintenance forum. Its the post with 5 yellow stars right below this one. As a lark pull that filter out and see if its clogged.

    Nothing to lose right? If that don't get it its time to pull the traction battery cover off and check for corrosion on the terminals/buss bars.

    Report back.
     
  2. andyprius

    andyprius Senior Member

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    There are several post on people that checked the HV, use search mode and read all post first. I went thru this about a week ago. You have to, disconnect the HV Bat with the orange handle, up and then left, the whole thing releases into your hand. Take off all the sheet metal ( many bolts ) Remove left wall to access hidden screws. Using a multi-meter I made the first contact with the black lead on a neg post and secured it with a alligator clip ( this way I could work with one hand ) an imperative when working with electricity. The danger of electrocution is way exagerated, but do think of what you are doing. I then put the positive post of the meter on each pos of each module. Result each module measured almost 8 Volts then 16, 24, 32 and 40. 48,64 then there is a junction ( I assume a new module wiring pattern. So find the next common negative and continue down the line, I believe I read about 140 Volts on that string ( Don't quote me ) You can also check one bat module at a time by putting the battery leads to one front and one back. You are looking for any non-consistant reading. This will indicate a bad module. I don't recommend taking the whole battery pack apart except :cheer2:where you have
    ordered a new battery pack and want to test and play around with the old pack ( as Bob Wison does ) In attempting to measure one or both of the big orange wire leads going to the front of the vehicle and checking the total voltage is impossible because there is no apparent common, ground, chassis connection, I sure as hell wasn't going to experiment with any unecessary arc welding. IF: You have no fear of replacing a circuit breaker in your house, condo, whatever and have a DVM and can use it, then go ahead and dig in BUT if your still getting at least 40mpg, Let it lie.
     
  3. 2009Prius

    2009Prius A Wimpy DIYer

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    If you have access to a ScanGauge then there is one XGauge that shows the max difference between cells.
     
  4. andyprius

    andyprius Senior Member

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    That is good to know, do you have the specifics on that Scan / X Gauge?
     
  5. northwichita

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    edit - I skimmed previous pages, may have missed this as a possible source, but have you checked the front brake calipers? They can bind , I've had to replace them on a different car, there the evidence was rapid brake wear on one side, and difficulty in pushing in the caliper when changing the pads. One quick check on the prius would be put the car in neutral on level ground at medium speed, and checking how fast it slows with and without braking.
    Also I didn't see where you usually drive, salt on roads in the northern/eastern states would cause some problems that the drivers in warmer states don't see.


    -------copy of previous post-------------

    What ODB II scanner (and why) would someone recommend for reading Toyotas?

    I bought the scangauge II, advertised here on priuschat and have been very pleased.
    http://priuschat.com/shop/product_info.php/products_id/74?osCsid=f8d2aa58492579d6f854e96ef04a14eb

    I do keep a prius Haynes auto repair manual under the seat to look up any codes that may occur. The scangauge gives instant readings of the engine temperature , 12 volt reading and other variables I have programmed into the gauge. The car basically has one big idiot light for a warning , my biggest complaint about the car.


    It will not display the CAN messages (most of the hybrid component values are CAN such as battery SOC, voltage, current, etc.).


    They can be programmed in to the latest scangauge with Xgauge feature.
    scan gauge site
    ScanGaugeII - Add-A-Gauge

    my possibly favorite priuschat link which allowed me to monitor some of these components like battery SOC voltage, percentage difference in SOC between cells, etc.
    Updated list of Gen II XGauges (ScanGauge)
     
    1 person likes this.
  6. 2009Prius

    2009Prius A Wimpy DIYer

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  7. andyprius

    andyprius Senior Member

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    I think the OPs gone.
     
  8. 240sxer

    240sxer New Member

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    I haven't changed the trans fluid yet. I bought a new house and i've been moving. I was trying to get it resolved before then now I'm at a loss for time. I'm going to try to change the trans fluid this week. If that does nothing I'll probably get a scangauge to check out the traction battery. I really don't feel like removing all those bolts and stuff. If I can just get a general indication that it's the traction battery I'll take it to the dealer.

    The brakes aren't binding at all though, i'd feel the car pull or at least experience additional rolling resistance.

    Another thing, that front cover on the bottom of the car is missing, I hit a curb or something and it was hanging down so I just took it off, but that was at bout 60k miles. I got good mpg after that still. The bad didn't start till late 90s. But I'm still getting 37-41 right now. It's just a good amount worse than before. After these few things I'll probably just leave it alone and deal with it.

    I just got a 2011 Sonata that we drive around most of the time now, the prius just drives me back and fourth to work mostly now (around 47 miles round trip). So the poor mpg isnt that big of a deal, it mostly just pisses me off because I want to know why it's so bad and I can't figure it out. I was gonna get another prius but this issue has turned me off to these hybrids. Although the mpg on the sonata sucks, I know it won't fall off the map when It rolls 100k miles.

    One thing I've noticed is that although the city mpg is poor, I think the freeway mpg took an even larger hit. I now notice that when I'm at around 80mph on the freeway the mileage is often barely above 30mpg. Before I'd be well in the 40s at these speeds. The City is clearly worse too but it does not seem like as much. I could be wrong though.
     
  9. ursle

    ursle Gas miser

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    3/4th's is optimal

    Hmmmmmmmmmmmm

    Hmm, I suspect the 12 volt battery as the culprit, I had an Optima bulge to twice it's original size once, Next..... is the Denso plugs, put some in two summers ago, got 62mpg all summer then mysteriously, 38mpg for three tanks, changed them out, get 53mpg on average now...

    So if you still have the Denso's in take em' out... and have the optima tested, if it just eats juice and never stops it would make for bad mileage.
     
  10. 2009Prius

    2009Prius A Wimpy DIYer

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    2011 Hyundai Sonata actually has quite good mpg:
    CleanMPG Forums - View Single Post - 2011 Hyundai Sonata “Challenge†- One day, 1,000 miles and just one tank of gas…
    Good luck! :)
     
  11. 240sxer

    240sxer New Member

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    I'll change the plugs again, but what should I change them with? I didnt notice any mpg difference when I changed them before whatsoever.
     
  12. edthefox5

    edthefox5 Senior Member

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    240 before you do that just humor me and check the VVT filter I mentioned on my VVT Filter post. I am really curious what that filter looks like at 100K unmaintained miles. Unmaintained meaning that VVT filter has never been cleaned on your motor. Its really easy just need a 8 MM Hex Head socket. Takes 5 minutes. My post had exact description on how to remove it.

    That filter cleans the oil that drives intake camshaft mechanical advance and retard. An important part of the Variable Valve Timing system.
     
  13. 240sxer

    240sxer New Member

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    Ok, let me find the post and I'll check that. For now I only drive the car to work and back, surprisingly the 105 degree weather has not hurt the mpg at all, it actually improved a tiny bit. I'm not sure what that indicates. But its still only hovering around 43mpg for a trip that normally would have been 55mpg or so. This is mostly driving 60mph or below.
     
  14. andyprius

    andyprius Senior Member

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    Try rebooting, click on andyprius.
     
  15. 240sxer

    240sxer New Member

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    Alright, sorry I have not followed up. I just replaced the transaxle fluid it made zero difference with the fuel economy. I also just changed the oil again.
     
  16. 240sxer

    240sxer New Member

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    Should I just take it to the dealership? If I do what do I have them test? Seems like I've done everything I can at this point.

    Replaced spark plugs
    Cleaned MA & throttlebody
    Replaced aux battery
    alignment
    Reset tires at 45psi
    Replaced air filter
    Changed Transaxle Fluid
    Changed Oil

    I don't really know what there is left to do at this point...
     
  17. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Parking brake drag?

    Raise up the rear axle, release the parking brake, and spin each tire by hand. Listen for a brake shoe rubbing against the drum.

    Front disc brake caliper stuck, causing brake pad drag?

    One way to check this is to use an instant read IR thermometer to see if the caliper temp is unusually high, compare one side with the other. Also, when driving the car, does it tend to move to one side or the other when you release the steering wheel while on flat pavement.

    Warm up the car. Reset the mpg gauge on the MFD. Then drive on flat terrain at a speed of 45-50 mph. What mpg is logged?
     
  18. myrisha

    myrisha Junior Member

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    Any idea how much it would cost to have a dealer do all of those things suggested above? My 2006 Prius has 119,000 miles on it - bought with no service records - don't know where to start on maintenance. Thanks!
     
  19. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Assume that no maintenance was done, and have the 120K mile service performed, as well as replacing the engine and inverter coolants from the 100K mile service.
    Toyota Parts and Service

    In addition to performing the items on the maintenance schedule, I recommend that you replace the:

    - PCV valve
    - serpentine drive belt
    - inverter coolant pump
    - front shocks and rear struts
    - clean the throttle body interior and throttle plate
    - check wheel alignment
    - check tire tread depth and replace tires as needed

    If you have a Toyota dealer service dept perform all of these services the price will probably be ~$3+K.
     
  20. 240sxer

    240sxer New Member

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    I'll do that test, but there is no way it's got anything to do with brakes. It rolls just fine, I'd notice the resistance in rolling inertia. I'll do flat for around 5 miles and let you know.

    Looking today it seemed like it spent more time putting power into the traction battery than anything else. It only occasionally fed power out of the battery, I stopped looking at it a long time ago so I don't have a whole lot of basis for what it should be doing. I can video it or something...

    I'm at 42mpg now on a trip that usually would average me around 50-55mpg