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Toyota Avalon Fuel and Fuel System Questions

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Comments

  • texasfx35texasfx35 Member Posts: 65
    I recently had the carbon canister on my '97 Avalon changed by the dealer for $665. The service engine light had come on. They replaced the canister, a vacuum valve and associated hoses they say need to be changed all at once. You may have your mechanic check out the vacuum valve and hoses to ensure they are not leaking fumes. I am surprised that what is basically an adsorption bed can fail like this. Seems the emission system should be more durable and waranteed longer.
  • kg4dkfkg4dkf Member Posts: 1
    My 1999 Avalon's owner's manual suggests premium fuel "if you expierence knocking or if you want better performance." That's pretty much the same as requiring it to me. Lucky for me, my company pays. I got the car 6 years old but only 25k miles (grandparrents drove it to the store for years). It was knocking bad! After two tanks of premium, the knock was gone. Now, with 51k miles and 7 years old, the car outperforms my friend's 2004 Avalon with 40k miles. I guess premium fuel helps.

    That being said, I use Amoco Ultimate fuel, which is also the cleanest burning fuel around. A friend who worked in a government fuel testing lab told me he would never buy anything else regardless of what the manual calls for. The pump handle even has a plastic window in most stations so you can see that the fuel is crystal clear. If you care about your car more than about the 20 cents per gallon (that's less than a 10% premium), use Amoco Ultimate (also sold at BP stations)...
  • finfin Member Posts: 594
    All Avalons run fine on regular, you just lose a little engine performance. The knock sensor will prevent pre-ignition in all but the most severe cases.

    Your car apparently was driven on cheap gas and the octane rating was probably the lowest available. Lower priced fuels have less of the additive that prevents carbon buildup. ALL fuel has the minimum additive standard set by the govt.

    ANY premium fuel from a name brand will help clean the engine as it contains more cleaning additives. Amoco is one of the best. Cheap fuel is no bargain, long term, as you suggest. But mid-grade from a name brand is fine. Enjoy your Avalon, great cars...
  • oilcan2oilcan2 Member Posts: 120
    Did some quick math,assume $.20 gal. more for premium a
    10k mile jaunt would only cost about $65 more and this is
    with no mileage increase.
    Here in south Tx all we can get is 91 octane.
  • jrainjrain Member Posts: 8
    Here is one to look out for. My check engine light came on, brought the car to the dealer--they told me my cap was loose--BS. They cleared the code, I drove off. When I went to put gas in the car, the pump shut off, like it was full. Went to 3 gas stations, same thing. Went back to the dealer today, they said my vapor canister was plugged with spiders webs--they cleaned it out, works fine.
  • bbland2bbland2 Member Posts: 1
    My gas tank takes forever to fill. It clicks off continually as if it is full and sometimes the gas will come out.
  • njavalonguynjavalonguy Member Posts: 35
    Hi,

    I have a 2000 Avalon XLS and off late i have experienced a drop in the mileage of the car with the onset of the winter season (last 1 week). I always use premium fuel and the used to get 24-25 (Indicated on trip computer display) easily in city driving conditions, however, I am getting barely getting 20-21 now even without switching on the heater. I continue to refill from the same gas station.

    Since this is my first experience in winter here, I'm not sure if any of you guys are experiencing similar issues to mine. Any inputs / advices would be of immense help

    ~A
  • obafunque1obafunque1 Member Posts: 13
    I have an Avalon 2000 XLS with 120K miles. Engine light on. Car will get dead after depressing gas pedal. Gas per mile around 14 Miles/gallon. OBDII scanner gave me Oxygen sensors ( all three bad). Replaced the Oxygen sensors and reset the computer. Spent around $500.00 in the sensors and the problem continue. Put the scanner again and now is giving me oxygen sensor bank 2 bad even when replaced with a new one. Car continue shutting off the engine when gas pedal depressed. Any advice please? Affraid to go to the dealer because the high priced cost associated with these problems.Thanks for all of your advise.
    Obafunque1
  • obafunque1obafunque1 Member Posts: 13
    Anyone living in the Houston, Texas area who has a good experience with a mechanic that I can trust with my Avalon? I really want to avoid the 'dealers' since they are killers and suck your budget real easy.
    If you have a good experience please share with me a name or a source that I can get in touch with.
    Thanks,
    Obafunque1
    :cry:
  • fnicholsfnichols Member Posts: 1
    I have the same problem on my 2000 Avalon. Does anyone know what the problem is?

    fnichols
  • lzukermanlzukerman Member Posts: 1
    Recentlly I filled my 2002 Avalon XLS with an E10 mixture. Coincidently, my car stalled when I put it in gear. After repeated startings it finally stayed on when I put it in gear. Because I thought the E10 might be responsible, I quickly filled the car with a non-ethanol gasoline after 40 miles. Since then I haven't had any starting problems.

    Has anyone heard of E10 causing any starting problems with the Avalon?
  • jbcameljbcamel Member Posts: 6
    What grade of gas does the owner's manual say is necessary for the 2008 Avalon XLS?

    thanks
  • melottmelott Member Posts: 3
    As spring has come, I have learned that the highway gas mileage of my 2003 Avalon is strongly correlated with temperature, ranging from 22 to 26 highway cruising at 75 mph. I don't know why.
  • finfin Member Posts: 594
    All Avalons will run ok on regular, 87 octane, gas. They run better on 89 octane midgrade. For the full power built in to the engine, premium grade, at 91 octane or higher, is necessary. This has been discussed many times in various Avalon boards and there seems to be general agreement on the answer.

    My experience, having owner all three generations of Avalon, is that midgrade gives enough mileage increase to justify the slightly higher price at the pump. And the car runs better than on regular. Moving up to premium produces nothing beyond midgrade in daily driving - not to me anyway.

    Great cars... enjoy one today... :)
  • jbcameljbcamel Member Posts: 6
    Thanks, but I want to know what the manual says. My husband is a "strictly by the book" guy, Whatever the owner's guide says he'll do.

    So, back to my original question: what does the Owner's Guide say for the 2008 Avalon?

    thanks
  • finfin Member Posts: 594
    Mine is an '07 Limited, not an '08, but the engine settings should be the same. Use 87 octane minimum. If significant knocking occurs, change octane grades or brands of fuel. Engine knocking, if severe, will ruin an engine. Hope this helps.
  • jbcameljbcamel Member Posts: 6
    Thanks, but again I need to know what the Owner's Manual says.
  • geo123geo123 Member Posts: 33
    Here you go!

    "Your vehicle must use only unleaded gasoline.
    Unleaded gasoline with an Octane Rating 87 (Research Octane Number
    91) or higher required for optimum engine performance.
    At minimum, the gasoline you use should meet the specifications
    of ASTM D4814 in the U.S.A. and CGSB3.5-M93 in Canada."
  • jbcameljbcamel Member Posts: 6
    Thanks!
  • hawiianavownerhawiianavowner Member Posts: 76
    I posted this elsewhere and thought this could help someone here:
    My 2000 Avalon has +130K and is running well except for intermittent rough starts, had to keep foot slightly on throttle at times. Googled and found it may be IAC valve. I know it's discussed earlier in this forum, but I ended up NOT removing it for cleaning:

    Disconnect neg battery cable first. Next remove the air regulator with the intake hoses attached. The hoses may be somewhat stuck, but are made of a hight quality rubber ($27 toy price for ONE), mine are 8 yrs old and were NOT brittle.

    Then remove the engine cover (easy),disconnecting the pcv valve hose, throttle cables (easy), disconnecting several vacuum hoses (easy) and sensor plugs (easy, if you push the release) but then there are more hoses with slip rings on them that are difficult...the slip rings need small and angled needle nosed pliers to get the right angle to release them. Then, slipping the hose off it's connector requires strong fingers to free them for their connectors. That took the most time, patience and sometimes careful prying.

    Once all that is done-90 minutes for me, there are 4 bolts for the throttle body that are medium easy to loosen with a metric wrench. The throttle body (TB) is now free to flip over, and access to the four screws attaching the iac to the TB is achieved...then comes the next big problem.

    The screws require an exact fitting philips screwdriver to remove...i have read some used an impact driver to remove it...others stripped the screwhead and used either a vise grip or the stripped bolt remover from Sears.

    I gave it a try with my available philips, saw that none of the screws budged, and decided to leave the iac on. Put the TB assembly back on right side up and over the next half hour squirted TB cleaner into the iac opening, letting it drip on to a rag i placed on the bottom of the iac. Also cleaned the TB ports with the cleaner and rag.

    My problem was intermittent rough idle, stalled starts, possibly due to a sticking IAC.

    The sticking is caused by oil vapor deposits on the IAC, i think it comes from the pcv valve, bec i found oil deposits iside the air regulator. Toyota service will recommend replacement at @ $200 for the part, plus labor.

    So after my "cleaning" I replaced everything in reverse order, the hardest part is replacing the slip rings to the orginal positions, tested the startup and there was no rough idling at all.

    It's only been one day, but others have not had their idle problems return after cleaning the IAC.
  • sbarkersbarker Member Posts: 4
    Hi,
    I have a Toyota Avalon with just 30,000 miles. the car is driven locally every day and has been getting 18.5 - 20.0 city type driving. This morning same type driving it says 16.4 - 16.9 What can couse this? The car runs excellent and is not driven hard at all. Can the dashboard mileage meter be crazy or is this a sign of maintence needed.
    Thanks
  • rpfingstenrpfingsten Member Posts: 154
    Sbarker....

    not sure why your mileage decreased, but even so I'd have someone look into that because even you previous mpg estimates seems alittle low to me. My avy avg's between 25 and 27 driving locally ( a mix of city and short hiway driving ). 18 to 20 would really be low in my opinion.

    Roland
  • thefireball451thefireball451 Member Posts: 1
    Incorrect: http://consumerguideauto.howstuffworks.com/1995-to-1999-toyota-avalon-6.htm
    States that premium fuel is required for the 1999 I have used in in the car since I owned it and have NEVER had a issue now it has 180K and sill runs like new.

    Consumer Guide® Road-Test Evaluation
    Except for more body lean and understeer on twisting roads, an Avalon drives much like the Toyota Camry. Although the Avalon's suspension is firmer, it still absorbs most bumps. Even on wavy roads, the sedan does not bounce or feel mushy. It also corners with good grip and moderate body lean. Because there's a negligible weight difference between Avalon and the V6 Camry, don't expect a discernible difference in acceleration or passing sprints. A test Avalon accelerated to 60 mph in 8.5 seconds--just about exactly as swift as a Camry. Toyota's V6 engine is just as silky smooth in the Avalon as in the Camry, and nearly silent. Better yet, it's complemented by a smooth, responsive automatic transmission. As for gas mileage, an early model averaged 19.4 mpg, driving mostly in rush-hour commutes. The V6 engine requires premium fuel.Space is ample for four adults, and six can tolerate shorter trips in models with the front bench seat. Leg space is generous in the backseat, and rear doors open wide for easy entry/exit. The trunk is wide and deep, with a long, flat floor. Low liftover height makes it easier to load and unload, too. Avalon's dashboard layout and materials are first rate. Large round gauges are legible. Both the stereo and climate controls are high enough to easily see and reach while driving.
  • finfin Member Posts: 594
    Actually, looking at what they wrote in the mag... most of it is correct. In general, the weak spots were as listed. Brakes wore out too soon, rotors had to be replaced too often, minor fluid leaks, etc. All discussed here on Edmunds.com..... But it was still a great run of cars, there were not that many problems as the model was improved thru the years. My '99 XL was near perfect. The fuel comment is in fact wrong as you point out, they all run on midgrade just fine. Mine produced better mileage on midgrade (89 octane) so I never used regular (87 in GA). Many of the '95 to '99's are still running here in Atlanta, you see them on the interstate or in a parking lot. Great cars... enjoy yours.. :)
  • mikecraigmikecraig Member Posts: 13
    Avalons do not require 91 octane fuel. Anyone who says otherwise has never read the owners manual. They may get a few more horsepower from 91 octane gas but anyone without a dynamometer who thinks they can tell the difference in a 3 to 5 horsepower increase is a fool. And how many times do you think you are using anywhere close to the maximum horsepower? Maximum horsepower for the 2018 Avalon is delivered at 6,200 RPM. When was the last time any of the pundits on this web site drove their Avalons at 6,200 RPM? When did you last drive it that hard? My guess is never.

    Here is the 2018 Avalon fuel recommendation from the owner's manual:

    "You must only use unleaded gasoline.
    Select octane rating 87 (Research Octane Number 91) or higher.
    Use of unleaded gasoline with an octane rating lower than 87
    may result in engine knocking. Persistent knocking can lead to
    engine damage.
    At minimum, the gasoline you use should meet the specifications of
    ASTM D4814 in the U.S.A."


    As for the quality of gasoline this is what the manual says:

    "Gasoline quality
    In very few cases, driveability problems may be caused by the brand of gasoline you are using. If driveability problems persist, try changing the brand of
    gasoline. If this does not correct the problem, consult your Toyota dealer."


    It's not a convincing argument to say you have been using XYZ gas for 40 years and NEVER had a problem. I want to hear from the people who have used ABC gas, had problems, switched, and the problem was solved. O! And you can't also have your MAF sensor and fuel injectors cleaned and then claim it was the gas.

    You can find your Toyota manual here: https://www.toyota.com/owners/resources/owners-manuals/avalon/2015?garagePrefVehicle=0&garageModelName=Avalon&garageYearValue=2015&addToVehicleList=false&remRecentVehicle=false

    You might get better gas mileage using premium gasoline but it has nothing to do with its octane rating. Regular 87 octane gas most often has up to 10% ethanol. Ethanol has lower BTU content than gasoline. You should also get better fuel economy using pure 87 octane gas without ethanol, the same can be said for using premium gas because premium gas in not available with ethanol. I have measured this myself over a 5,000 mile test interval. I got 3% better fuel economy, 24.7 mpg vs 24.0. Not worth the difference in cost of buying pure gas. I don't rely on what the cars computer says. I do it the old fashioned way by logging my mileage and fuel supplied at the pump. I've recorded a mpg range from 18.6 to 31.6 over a 9,000 mile interval under the same driving conditions. A single tank of gas is insufficient for a meaningful test. Even my 5,000 mile test must be considered suspect. After all I was not able to perform it under controlled conditions.

    There is an argument to be made that cars like the Avalon with variable valve timing can slightly improve performance using premium fuel by allowing the valve timing to be optimized. But I have never seen proof. Again anyone who thinks they can feel any difference without a dynamometer is kidding themselves.

    The BTU content of gasoline has nothing to do with the octane rating.
  • kyfdxkyfdx Moderator Posts: 234,725
    "because premium gas is not available with ethanol"

    I don't think that's true. Ethanol actually raises the octane rating of gas, even though it has lower BTUs.
    There may be states where premium doesn't contain ethanol (Montana?), but in CARB states, or Midwest states that use reformulated gas, premium definitely contains ethanol.

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