Throttle up problem on Taco V6 MT on dpressed cluch

My 09 2.7 with 5 speed manual does it.

At 75 mph with cruise control on I can shift to neutral using the clutch and the rpm's will start to rise and if I don't blip the gas pedal the engine RPM's will soon be bouncing off the rev limiter

Applying the brake has no affect on the runaway RPM's.

Some how mashing the gas pedal for an instant will stop the runaway condition

It is a software control issue, not a mechanical one.

It's rather unnerving when it happens and the only way to stop it is by turning off the ignition. I've learned to drive around the problem.

I've thought of dropping it back into gear but figured it would destroy the clutch, which the dealer would not cover and say the damage was from abuse.

 

Just got my 2010 V6 MT back from the dealer. Its 5 weeks old now with ~3000K on it. One of their top mechanicks took it out for a test drive. First of all the dealer said that throttling up by about 200 RPM is normal as alot of you said to burn off excess fuel for emission reasons, its designed that way. In the old days engines use to dump that fuel in the exhaust but not anymore so that is normal.

The mechanic found that when the engine was cold the problem did not show up but as soon as the engine got to operating temperature it could throttle up by 500 to 1000 RPM which he thought was abnormal. In doing research he discovered that Toyoto released a technical bulletin that identified this problem. It is caused by the flywheel being engaged to the engine abit longer than it should when the cluch is pressed. The inertia/momentum of the truck's forward movement, even though your foot is off the gas, causes the engine to go faster than it should thus raisning the RPM. Sounds like a reasonable explanation to me.

Now, the reason that the flywheel remains engaged is because of a manufacturing defedt in the rivits that hold flywheel mechanism toghther if I undersatnd correcty. When the engine heats up, the expansion is just enough to cause this effect. As this condition worstens, you will notice that it gets more difficult to get the truck in gear and in the limit when the rivits give way, you will need a tow truck to get you back to the dealer. Note the throttling up should be in the order of 500 to 1000 RPM before you really need to be concerned. You be the judge 200-300 is normal.

There you go guys, I have a brand new truck, my dealer ordered an new cluch flywheel, pressure plate and bearing assembly. Shold be in soon. the mechanic recommend changing all that sooner rather than later. I hated to have this done so soon but the guy did the resarch and so I trust his recommendation.

By the way Toyota knows where that part was manufactrued and the range of VIN numbers of trucks that were built using parts from that manufacturer. My VIN # fell within that range.

Dont panic but check it out, will keep you posted

 

Hmmm... If it's a TSB, usually the dealer list it on the service paper as a TSB with the TSB number after they perform the fix. Keep us posted when you get it done.

 

Sounds like crap to me. For one the flywheel is bolted to the crankshaft so it is always 'engaged' to the engine. What I believe the tech means is that the clutch disk is still engaging the flywheel. A simple test of this theory is to remove your foot from the gas pedal while driving (without touching the clutch) as this would still have the clutch engaged as the tech explained. Does the "inertia of your vehicle" cause your RPM to suddenly increase? I didn't think so. You might want to look for a new tech.

Now on an older vehicle if the RPM increases when depressing the clutch it means that the cable is sticking. In a drive-by-wire system it could mean that the gas petal switch is not returning as quickly as it should. At idle you are not using any extra throttle so you wouldn't notice a surge if you pushed the clutch. I guess this could be tested by taping your foot to the gas pedal to ensure that it is pulled fully back before engaging the clutch. If that helps reduce the RPM increase then that might be part of the problem. If not then it definitely a computer/programming issue.

Kudos to the dealer for not just blowing you off, I guess, but the free clutch won't do squat for the problem.

 

You are correct about the cluch disk. he was talking about the disk shich he said had some type of break pad type material on it. Apparently its held together by rivits wwhich loosen and come appart thus making the disk seperate. He said that the symptoms that I have were identified by Toyota in I believe a TSB and that my VIN # falls in the range of Tacos that used the faulty disks. Toyota has identified the manufacturer and knows which vehicles have that disk.

Sorry for the inaccurate explanation, I am not that technical mechanically. Does this explantion make sence to you? I have nothing else to go on and the dealer tried his best to find the problem. If it does not make sence to you, how would you explain the throttling up by as much as 1000 RPM expecially when the engine is hot especially when shifting from 2>3>4? When the engine is cold here cold means -10 to -15 C it does not seem to rev to that extend.

Thoughts? - Thanks

 

same here, but not a big deal.

 

My fiend tat has been tried many times by me to make sure that it was not me. When I went for a test drive with the dealer Teck he accused me of just that. I turned on the ligt inside ht etruch (it was dark outside) and let him watch me shift. When he drove the truck it happened to him as well. The final anaysis waas done by a different teck who is the one who said the 200 to 300 increse between shifts is normal. He found that the increase when the engine got hot was abnormal and too the time to go through the Toyota notes where he found mention fo the problem with the rivits which also indicated that the excessive increase in RPM is the first sign of trouble. The next thing that happens is that you will find it more and more difficult to shift them in the limit when the disk seperates, you will have to call a tow truck.

Thats all I can say. What do you think?

 

that is exactly what it is supposed to do personally i feel that it gives me alot smoother ride it is a great feature

 

My problem is once the engine gets hot the RPM most of the time will throttle up by as much as 1000 RPM between shifts. Toyota says that 200 - 300 is O.K. The last teck agreed that 1000 RPM up was unusal (he test drove it) and found a TSB outlining this problem and associating it with bad rivits being used to hold the disk together. Once these rivits start to come loose, the over - reving occurs followed by difficulty shiifting. Following full seperation, you will need a tow. This is what the dealer told me. They ordered a new cluch, pressure plate, disk and bearing assembly. I only have 3K on my truck. I guess the acid test is weather it does it again once the new stuff is installed.

What do you think?

 

Ok, I can see that if there is a clutch problem that it would definately lead to difficult shifting because it isn't fully disengaging. However, it is impossible for the clutch to have anything to do with the surging problem. If anything a sticky clutch would cause engine RPM to decrease. These are completely separate incidents.

 

Hmm, I wonder if this could be what's causing my rough shifting into 2nd and 3rd....? Anyone know how to find out what VIN #s are affected with this issue? If there's a TSB about it, where can we get a copy?

 

Hi all, I'm new to this group and I just purchased my 2010 Taco in November. I first noticed the rise in the rpm on my wifes '05 Corola XRS. I also have the same issue on my Taco, but it seems the sample rate is MUCH better, smoother throttle response. I would like it if Toyota would not trade off drivabilty for a few milligrams of unburned fuel.

 

My 2009 does that little surge thing when the clutch is depressed also... BUT it will do it if you play with the throttle anyway, regardless of whether you're using the clutch. I attribute it to the emissions garbage and the sucky throttle-by-wire lack of responsiveness. There's simply too much electronics, sensors, and RF involved, for any of that "linkage" to work nearly as well as a good old steel cable. I would pay to have a steel cable like my '96 had. I find it irritating and it took me about a month to be able to shift smoothly again, but I don't think there's anything wrong with it... other than the imperfect electronics. Just try reving the engine in neutral a couple of times, focus on the throttle responsiveness, then go do the same thing on a motorcycle or a car with a steel throttle cable. No comparison.

As for the clutch disk. Yes, they are generally riveted to the steel plate of the disk. The material could be equated to a brake pad. It slips on the flywheel surface as you engage/disengage the clutch. When it wears down as far as the rivets, it will score the flywheel surface just like a brake pad can score a brake rotor. If you let it go, it will eventually destroy something.

That's not to say there couldn't be faulty clutch disks, especially as some of your dealers are replacing them under warranty. A clutch is usually not something they'd pay for. In my experience, Toyota has had great clutches. My last one was just fine with nearly 150,000 miles on it. I haven't seen a "new" clutch disk and pressure plate to compare to an "old" one, but the technology is exactly the same and they can't be very different. Generally, they're probably quite good.

Sorry to carry on.

 

I've been doing a lot of test drives lately before I make my purchase and I've been looking for this in the MT's that I've driven. Anyway, I've driven 3 different MT's and only 1 of them did it. It was an '09 w/ ~1800 miles on it. The two '10's (mileage 77 and 179) that I drove did not have the rev bump between shifts. They both felt really good as far as shifting is concerned.

 

i have a 09 V6 MT. When i put the clutch in to take it out of gear and to stop, the RPM bumps up. Sometimes more than others. Very annoying. I had an older truck that when you put the clutch in, the RPM dropped to idle. (It also got about 8 mpg better)

This feature drives me crazy. But im glad im not the only one who noticed it. Is there ANY way to stop this?

ive also noticed leaving it in gear and letting off the gas pedal, it will stay at speed for about 2 seconds, then a noticeable drop and slow down.

Shifting to neutral and slowing down, RPM's go up until i get to 10mph and they finally drop down to a "normal" idle. (around 750)

 

I think theres definitely something funky with the ECU and the RPMS in my 2010 6MT

Ive noticed the RPMs staying up briefly after pressing the clutch which I find really annoying. It also seems that maybe RPMs are tied to the speed of the truck. For example, I start slowing down, throw it in N, then coast to a stop with my brakes. As I slow down, I notice my RPMs drop roughly in proportion to my speed.
Today I was on the highway and pressed the clutch to see if the engine would idle and it only dropped the RPMs to ~1k. It ordinarily idles around 700 I think. I would expect with the clutch engaged, even with the EPA throttle thing everyone here has mentioned that the engine would idle if the rpms were not somehow tied to mph or at least tire movement.

What has really been bugging me since it happened, was the RPMs seeming to rise randomly while I was slowing down and stopped the other day. It was cold out, I had just left in the morning, and the engine was warm. When I was slowing and when I was stopped at a light I noticed the RPMs were unusually high, 1.5 - 2.5k (even while stopped).
I confirmed that my foot wasnt accidentally hitting the gas while braking, and that my floor mats werent pushing against the pedal (I removed that dumb do not remove this tag tag). Eventually during my drive the problem went away, and hasnt happened since.

This all just reaffirms my belief that these recalls are a software problem. If a pedal gets stuck, the cars speed should plateau (assuming level ground of course), not increase.

 

Can anyone actually post the "alledged TSB" ???

 

no, but i let off the gas before the clutch...IMO, it all boils down to that stupid fly by wire BS

 

going to the dealer this weekend about this! Not too impressed with these clutch systems and tranny's

 

I can drive my truck smooth, but it shouldn't take that much finnesh to drive a 25K-30K truck!

My dad drove it for the first time this weekend...and yes he can drive a stick....he was sooo ruff on it!