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Comments
how is a slow measurement forgiving w.r.t speeding? isn't the error likely to cause drivers to travel faster than they think, and therefore also put them closer to the threshold where they are deemed speeding via "calibrated" reference measurement device (radar / lidar), and thus be flagged to get pulled over?
if there's forgiveness, then perhaps these cars register less total miles travelled on the odometer (assuming the error affects both speed and miles travelled indications).
if so - oh - then wouldn't people be getting their regular preventive maintenance performed a little later than recommended?
But it would also mean that you would need a smaller diameter tire to show the correct speed would it not? (Now maybe you were already implying that the 17" wheel/tire combo produced that smaller diameter?) To my (possibly flawed?) thinking, a larger diameter tire, with its matching larger circumference, would take you further down the road with each revolution making for a higher actual speed.
That seems to me to mean that your speedometer error would get worse, showing you traveling now maybe 4+ mph slower than your actual speed (I'm too lazy to do all the math to show what difference the .9" would actually make).
I'm thinking that you need a slightly smaller tire diameter tire to take you less distance down the road with each revolution and so to bring your actual speed down to what your speedometer says it is. Isn't that correct? (If not, please use simple terms to help me understand.)
Of course, in reality, a judge would probably throw out a case of less than 3 mph over as a waste of the court's time....
First off, it's not my car we are talking about.
I was commenting that if the poster was claiming their car (and the courtesy car) were BOTH registering unit (miles) traveled per unit time (hour) slow, then that would mean:
if customer thought he was travelling at speed x, he'd actually be travelling faster than that...
poster was claiming the vehicle was measuring slow with respect to some other reference device used. I don't know, maybe the poster was claiming the distance traveled was less than the reference measurement. not sure...we'd have to ask the poster.
As for tire radiuses, if the radius decreases, circumference decreases (C=2*pi*r).
Presuming speed is sensed by some axle or gear making revolutions per unit time, then, a smaller radius wheel means the wheel must revolve faster (and thus speed measured by the car faster) for the same distance traveled as a car with the design size radius wheels. Also, this would mean, distance measured (probably by totalling number of revolutions) would be mis-calculated as higher than actual for a smaller than design-size wheel.
Conversely, with larger radius/circumference wheels than design, then they'd not have to make as many revolutions to travel the same reference distance, thus they'd tend to report a shorter than actual/reference distance travelled. It also would mean, they'd result in an under-reporting or slower than actual speed, because the number of revolutions per unit time would decrease.
I hope I have that right. Apologies if I don't.
abbey6: Help us understand. What exactly were you saying? Was it that the Sienna speedometer reported you going 27 mph, say, while you were actually travelling 30 mph (as measured by some other device)?
Hmmmmm.... It just might turn out that I was confused about being confused! ;-)
That last I have used to defeat tickets a few times, if the officer hasn't checked his tire inflation pressure recent to writing a ticket based on his speedo.....
Speedometer calibrations/certifications for purposes of officers writing speeding tickets is done with the speedo "head" only, on a test bench, NOT as installed in the actual vehicle.
as wwest alluded to, tire inflation would have some impact in accuracy. it could be experimentally determined too.
you could also have some fun in determining impact on indicated miles-per-gallon, vs. actual miles-per-gallon.
I have been reading R&T, C&D, PM (remember Tom McCahill?), PS, MT and various European car mags for the last 30 years and never recall one roadtest quoting a speedometer that was under reporting the speed. I have seen some that come close to reporting the correct speed up to 50 or so but after that the variance due to needle bounce, cable windup and other factors exacerbate the tolerance issues making them less accurate above certain normal speeds.
That doesn't mean that there isn't at least some out there that do under report, but I doubt it would under report by 3MPH at 70. Especially in a modern vehicle that uses some pretty good calibration and processes to understand what is displayed and used for information by the rest of the vehicle.
My 78 Targa reads 90 when I'm doing 80 and the distance to Memphis is 2750 instead of the actual 2500.
But keep in mind that manufacturers don't just increase the rim diameter and put the same tire on. They generally keep the wheel circumference the same by reducing the sidewall height by a corresponding amount. Thus, if you upgrade to the 17" wheels (1 inch larger rim diameter), the tire sidewall height is reduced by a corresponding amount, so the circumference of the whole wheel will remain the same. I'm sure there are minor variations in circumference, and I haven't done the math on these particular combinations, but circumference should be pretty much the same on factory option wheels.
Tom
Most would interpret this as meaning the speedometer was reading 3 mph slower than the actual travel speed (ie: reading 67 when the true speed was 70) in which case going to a tire/wheel combo with larger overall diameter would indeed WORSEN the problem. Which is exactly what dako_tian was saying.
However, abbey6 has since then clarified that the problem is the reverse (ie: reading 70 when the true speed is 67). In other words, the speedometer reads too fast (not slow) in which case, yes, a larger wheel/tire combo would help.
Or Sienna owners could just inflate their tires to about 120psi..........8^)
Tom
serrano: I was just going along with abbey6's statement that the difference would be .9" between the 16 and 17 inch tires. I agree that, most generally, the outer diameter of the tire remains the same for manufacturer's optional wheel sizes. This avoids them having to recalibrate the speed/odometer for differing tire sizes or, far worse, to begin a discussion like this in attempting to explain to the customer that their speedometer registers too slow (or is that too fast?!?)! ;-)
I have just recently changed the oil in our new 04 Sienna also (changed @ a little under 2000 miles). I also found the filter to be a hassle. I was using one of those offset filter wrenches that contracts around the filter (with the handle at an angle to make this somewhat do-able).
There is also a filter wrench that looks like a giant socket wrench (1/2" drive). I took one of my new Toyota filters down to an autoparts store to make sure I got a good fit. I haven't actually changed the oil with this setup yet, but I did fit it over the filter and I think it will make it trivial.
Fram does have a filter for the Sienna. Try PH3614 (3614 being the key - they have a variety of different types). I have used Fram filters for about the last 16 years so I may go back to them. HOWEVER, I did try the PH3614 filter and none of the "socket wrench"-like filter wrenches fit over it nicely. If they is consistently the case, I will (regrettably) stick with the Toyota filters. Price-wise, the filters are very comparable in price, but I have just "grown up with" the Fram filters and they have never let me down.
BTW, I'm sticking with full synthetics and doing the changes at 5000 miles intervals (after the first at 2000 miles). Naturally changing the filter with ALL oil changes!
The wrench is called an "oil filter cap wrench" (I just looked at the cardboard which is still with the wrench). Any decent auto parts store has them. I got mine from "Western Auto" (formerly part of Sears), but I will keep my eyes open for a better quality one - this one is kind of cheap looking).
The "socket" that fits an american made filter, Fram, "almost" fits a Toyota filter. Just close enough that you can't get it off after you use it to tighten the filter.
I think there IS a model that will fit the fram filter and a SEPARATE one that will fit the Toyota part. Apparently it has to do with the number of "flutes" on the end of the filter (the number of flat surfaces). The Toyota filter is a 76mm, 14 flute filter. The Fram has more flutes if I recall correctly.
I never was able to find anything about allowable errors.
Steve, Host
I haven't looked into how a more modern speedo works, but have taken apart my share of the older all mechanical type.
The following url gives some nice graphics of how a speedo works and the parts involved.
http://home.jtan.com/~joe/speedo.htm
I haven't found a document that details speedo error allowance, but will look around again.
Twice a day.
Your speedometer, as bench tested, is likely only accurate at one specific speed, the "mechanics" of the device do not act in a linear fashion. So being accurate at, say, 60MPH doesn't mean that you won't be off above and below.
And that's speaking of only the speedometer "head" itself.
I suspect tire inflation, or not, cold in the morning, hot after drive, etc, is the single biggest contributor to speedo inaccuracies.
What's your tire pressure starting out on a cold morning vs after having driven 20 miles or more?
* Dealer filled new tank with gas in conjunction with replacement
* A few days later the “malfunction indicator lamp” came on and engine eventually failed to start
* Dealer towed the vehicle in for maintenance and said a cylinder was not firing properly (??)and reprogrammed the engine computer (??)
* Reprogramming seemed to correct the problem only temporarily
* A few days later...had a lot of trouble starting and the “malfunction indicator lamp” returned
* Tried to drive to same dealer for maintenance but the engine stopped completely on a busy street –- was stuck blocking traffic in a new 2004 vehicle that wouldn't start!
* Vehicle was again towed to dealer
* Dealer said the vehicle has "bad gas" and they will do a drain and flush (??) to clean out the dirty fuel from the replacement tank
* Now awaiting completion of "flush" work to find out results and pick up the van
* Any thoughts on what damage this bad gas has possibly caused to the vehicle motor and/or has anyone else had problems after the tank recall? Additional Advice?
*** Prior to taking vehicle in for the 2004 recall we had no engine-related problems
I am also starting to notice some transmission issue on my LE. The gear skipping usually happen at low speed (less than 30 mph) on a low-grade slope surface. As soon as I step on the gas, the engine/transmission rev in neutral, a couple seconds later, it latches on to gear, and the entire vehicle chokes then moves on. Does it sound like the torque convertor problem some of you mention earlier?
If I bring it to the dealer, will I need to sit with the mechanic to reproduce the problem to him, or the dealer would have equipment to tell if there is really a problem?
This problem does not happen if we drive it with gradual accerlation, only happens with sudden accerlation.
Thanks for your help!
Sam
The messages from this discussion will be added where the current Toyota Sienna Owners: Problems & Solutions leaves off. Unfortunately, we don't have a way to make the messages "mesh" together by date.
The final discussion will be called "Toyota Sienna Owners: Problems & Solutions" and will be accessible from Owner's Club, Vans and M&R message boards.
Stephen
Why not rename the older discussion to show the years that it relates to, since this discussion is already clearly named?
It just occurred to me too (just in time to edit this post) that people looking to buy the new Sienna and trying to see if it is really having significant first-year-model troubles are going to be stymied. Please keep the discussions separated into the distinct vehicles they are to better serve your guests.
As I'm sure many guests are doing, I am reviewing the boards for new year model problems. Having one board with exactly that information on the new model year has been invaluable and makes it easy to read through posts. Great idea to rename according to MY's.
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When the '99 Odyssey came out, it really was a new model. Ditto the Sienna vs the Previa.
The new Sienna is new, but it's not so totally different from the old one that people won't have problems talking about their '00 sludge vs their '04 gas tank in one area.
I'd just as soon make things consistent with a single problems discussion - the old hands can help even if their ride is a bit older, and the newcomers won't have problems figuring out where to post. I'm OCD that way :-)
Remember too that Town Hall's roots are in what some of us consider the original bulletin board and Usenet format from the early days. Conversation based boards are nice in that you can you scroll through and pick up tidbits that you'd miss with a narrowly threaded board and you get to know the other owners a bit. Plus we have a good search function so if you want to ferret out some specific little '04 problem in a bigger problems board, it's easy to do.
Steve, Host
From the size to the mechanicals to the power windows in the sliders to the seats to ??? this is a new and different vehicle. This is not just a stretch or even just a slightly-scaled up version of the older vehicle. The name is the same, but they could just as easily have renamed this minivan and claimed it as a totally new product.
It was drastically changed as Toyota realized that they were too timid the first time, not realizing that a little bit larger than the Previa would not satisfy the Americas-market. They looked around at the key design features and deftly incorporated almost all into this newer, finally big enough minivan. All this has to mean new (bigger?) problems not related in any way to the older, smaller version.
They still need to hire some of the Honda body designers to make a truly attractive vehicle, but hey, you can't have everything, huh?!? ;-)
Oh well, I'll go back to my domestic (is Mexico domestic?) product with its inferior reliability reputation (though methinks times have changed.... again!).
TSB TC007-03 TC3001 .8 T1 26 T2 99 89661-09101
Correction: Performed ECM for engine and transmission, performed bulletin and rechecked by test driving car.
I know these three models share the same engine, do they share the same transmission as well? If so, that explains.
It is interesting to see that the problem was reported as early as March as Canuck13 did, but when I bought my Sienna in September, I still noticed the problem. So I think it might not be related to VIN range.
If you are unlucky like us and felt the problem with your tranny, I think you should reproduce it to the dealer and insist that they perform the TSB to your Sienna/Highlander/RX330.
I took a short test drive in a highlander ('04) today. I didn't really notice any hesitation, but I didn't really try to produce the right conditions either. Did notice that the powertrain was smooth, and felt like it would scott pretty well if you nailed the go pedal.
2020 Acura RDX tech SH-AWD, 2023 Maverick hybrid Lariat luxury package.
The Lexus had no problems in 4 years and is an excellent vehicle but I needed more room.
Lexus does not make a minivan but I think they could have put a Lexus badge on the XLE with few complaints. I even like the appearance which others on this board have complained about. I added some creative pin striping which helped.
I miss the memory drivers seat, the elapsed time keeper and the 10 CD changer but the compensations include the tighter turning circle which makes parking much easier, a compass (the Lexus didn't have one), much better gas mileage and much better space utilization.
One problem I can't seem to solve is the headlight aiming when I carry 7 passengers. The front end rises slightly and the headlights shine in the eyes of oncoming drivers. My owners manual shows a switch to the left of the steering wheel to adjust the headlights but my van does not have it (the space is there for it).
Can anyone offer a solution for this problem?