Weird thing with my Sienna....

[Thai]

Hey all,

With all this talk about unintended acceleration, i want to ask the forum about my little problem with the Sienna. Usually, after a cold start, my Sienna would have a tendency to move forward. For example, driving away from work, there is a stop sign. At the stop sign, i would put my foot on the brake pedal. But, while my foot is on the brake pedal, I can feel as if the vehicle still wants to go forward...this is much different than normal. And as i ease off the brake pedal, you can feel the "urge" of my car to want to take off...hard to describe the feeling, but it is kinda like holding back a lion who is hungry and is dragging you along. During this whole time, the car is running well...no error lights...no shudder or anything like that. And after accelerating from the stop sign, the car runs well. This normally happens only after my Sienna has been parked for a long time. It is reproducible too.

At first, I thought that it was because my transmission is in 1st gear and that the engine ECU is revving the engine more than usual to warm up the car quicker. But, with all this talk about gas pedal malfunctioning, i am second guessing my "theory." And you guys know me...i am not a neophyte when it comes to cars...this feeling like my car wants to take off at a stop sign is very significant. I have never lost control due to this because i am now very careful not to release the brake pedal too early and always provide strong pressure to the brake pedal. And no, i do not plan to sue anyone over this...i do have extended warranty!

And i do need to check my gas pedal to see who made it. My 2005 Corolla never had this "issue" nor any of my other cars. My Mercedes ECU also has the protocol to warm up the engine (aka being in 1st gear longer) and i have never experienced this "push" at a stop sign after a cold start.

Do you guys experience this "issue" on your 4runners or other cars??

Thanks in advance.

 

[JAC]

Hey all,

With all this talk about unintended acceleration, i want to ask the forum about my little problem with the Sienna. Usually, after a cold start, my Sienna would have a tendency to move forward. For example, driving away from work, there is a stop sign. At the stop sign, i would put my foot on the brake pedal. But, while my foot is on the brake pedal, I can feel as if the vehicle still wants to go forward...this is much different than normal. And as i ease off the brake pedal, you can feel the "urge" of my car to want to take off...hard to describe the feeling, but it is kinda like holding back a lion who is hungry and is dragging you along. During this whole time, the car is running well...no error lights...no shudder or anything like that. And after accelerating from the stop sign, the car runs well. This normally happens only after my Sienna has been parked for a long time. It is reproducible too.

At first, I thought that it was because my transmission is in 1st gear and that the engine ECU is revving the engine more than usual to warm up the car quicker. But, with all this talk about gas pedal malfunctioning, i am second guessing my "theory." And you guys know me...i am not a neophyte when it comes to cars...this feeling like my car wants to take off at a stop sign is very significant. I have never lost control due to this because i am now very careful not to release the brake pedal too early and always provide strong pressure to the brake pedal. And no, i do not plan to sue anyone over this...i do have extended warranty!

And i do need to check my gas pedal to see who made it. My 2005 Corolla never had this "issue" nor any of my other cars. My Mercedes ECU also has the protocol to warm up the engine (aka being in 1st gear longer) and i have never experienced this "push" at a stop sign after a cold start.

Do you guys experience this "issue" on your 4runners or other cars??

Thanks in advance.

SOrry to say this but I have.....No matter how hard I pushed the brakes..the car keeps going. It happens like twice a few months ago I always been thinking I needed new brakes .It is so weird because when I get into my 2010 Kia soul as soon as my foot touches he brakes it stops right away It almost feel like when you learning to drive a manual transmission and u dont do it right that its sotps right away....but because I am so used to pushing the brakes harder with the runner Thats why this happens to me with the Kia. For real...with the Runner I got to really push that pedal or try to hit it way before the stop sign especially when I am going above 55-60 mph. One day I almost killed a pitbull because of that . He just came out of no where and I hit him but almost when the car stopped so he didn't get hurt. But I hit him. If it was the soul...it would be and instant stop.

 

[CJ3Flyr]

I think your theory about 'warming up' is what you're experiencing. I would guess your heightened awareness is playing into it some AND there's no doubt you need to be aware :bigok:

My Titan used to pull pretty hard until it warmed up too... My 4Runner does it some but nothing extraordinary.

 

[Thai]

I think your theory about 'warming up' is what you're experiencing. I would guess your heightened awareness is playing into it some AND there's no doubt you need to be aware :bigok:

My Titan used to pull pretty hard until it warmed up too... My 4Runner does it some but nothing extraordinary.

Ok...that is what i thought, but with all this talk, i was getting a bit paranoid....

 

[Kmvreter]

... Usually, after a cold start, my Sienna would have a tendency to move forward...
... Do you guys experience this "issue" on your 4runner...

Yes, it's seasonal.
Is it colder in Texas now?
Test it out. Park so you can pull straight out, not in reverse. Turn the A/C off and don't use defrost mode. Later, after cold starting the van it will rev high and then settle after a few seconds. Don't let it warm up. Note the rpm's. Put it in gear and note the rpm's again. Start driving and come to your stop sign. What are the rpm's? Pop it into neutral and it will rev higher and then settle. What are the settled rpm's? The last 2 readings shouldn't be any higher than the first 2.

 

[Uneek]

Thai,

My Toyotas do it and slightly firmer hold on the brakes is needed. The engine idles a bit higher when cold.

My Mazda did too and engine would rev much higher right after initial start up. Some say the ECU is set to rev the engine to get oil pressure up and to the valves.

 

[Thai]

Yes, it's seasonal.
Is it colder in Texas now?
Test it out. Park so you can pull straight out, not in reverse. Turn the A/C off and don't use defrost mode. Later, after cold starting the van it will rev high and then settle after a few seconds. Don't let it warm up. Note the rpm's. Put it in gear and note the rpm's again. Start driving and come to your stop sign. What are the rpm's? Pop it into neutral and it will rev higher and then settle. What are the settled rpm's? The last 2 readings shouldn't be any higher than the first 2.

Yes, it is colder now.

Thai,

My Toyotas do it and slightly firmer hold on the brakes is needed. The engine idles a bit higher when cold.

My Mazda did too and engine would rev much higher right after initial start up. Some say the ECU is set to rev the engine to get oil pressure up and to the valves.

Yeah, that is what i figured...cool. Otherwise, i am super happy with the Sienna.

 

[sprtpilot]

Sienna "uncommanded (uncontrolled) acceleration"

You might want to read this thread:



Toyota Sienna Uncontrolled Acceleration - CarSpace Automotive Forums