Car slowing itself down when coasting?

[PieIsAwesome]

I just bought a 2006 Honda Civic a week ago with auto transmission and I have noticed a weird issue where the car feels like its braking (without me applying brakes of course) very slightly at low speeds while coasting.

Is this normal? I have done a bit of research, and according to some people, some cars seem to have a feature where the transmission slows the car down during coasting to assist the brakes and reduce brake wear.

Or might there be some brake components that are worn out? I bought this from a dealer, but maybe they missed something.

I plan to have it checked out, but I want to have a better idea of what the problem might be so that I can better communicate it to the guys checking the car out.


This thread is almost 4 years old...?

AT Moderator
Bartman39

 

[ShawnD1]

What's the engine RPM like? If it's high, then yeah it's the tranny slowing you down and it's working as intended.

My car is a Corolla and it does the opposite. It'll be in top gear even when rolling at 20km/h then lightly touching the gas makes it drop gears. Instead of slowing down, it actually speeds up at low speeds if I don't touch the pedals.

 

[TakeNoPrisoners]

Engine braking. Higher compression motors will do this more so then low compression motors.

 

[Throckmorton]

Engine braking. Higher compression motors will do this more so then low compression motors.

It's an automatic, the torque convertor should let the drivetrain spin freely when he lets off the gas and doesn't brake.


Maybe it is a feature. My Jeep engine brakes if I put the selector in "2" or "3".

 

[Zenmervolt]

It's an automatic, the torque convertor should let the drivetrain spin freely when he lets off the gas and doesn't brake.

A torque converter is not the same as a sprag clutch.

While a torque converter is much less efficient at transferring energy "backwards" (i.e. from the wheels to the engine as occurs during engine braking), there is still some degree of engagement and therefore some degree of engine braking.

There are some automatics that do use a sprag clutch for first gear for smoothness reasons, which can reduce or eliminate engine braking, but that's not because of the torque converter.

ZV

 

[RedRooster]

Drive around for 20 minutes then get out and put your hand near all four brake rotors(or drums if Civics still used those in the back?!). One of my Camry brake lines packed it in one time, and the one caliper kept dragging. Felt way different than normal, and the rotor was cooking. Got the line replaced, and it never happened again.

 

[DominionSeraph]

Some cars have a noticeable first gear.

 

[Raduque]

My dad's Solstice loses a lot of sped while coasting, but my Altima will coast for a long time. My F150 is somewhere in between.

 

[LTC8K6]

Put it in neutral. If you still feel the drag, then you need to investigate further, such as a dragging brake.

 

[ElFenix]

first gear does that.

 

[PieIsAwesome]

I'll have to experiment and check the RPM then, and try coasting in neutral.

 

[Doppel]

I thought all cars with autos did this.

 

[bruceb]

That is normal for cars with automatic transmission. I know my Pontiac will do it. And if I am on a steep downgrade, I won't hesitate to consider a manual downshift to "3" or "2" from "D" depending on the grade.

 

[Bartman39]

That is normal for cars with automatic transmission. I know my Pontiac will do it. And if I am on a steep downgrade, I won't hesitate to consider a manual downshift to "3" or "2" from "D" depending on the grade.

Yep some do some dont depending on the type of auto transmission... Just sounds like its down shifting which will result in that engine brake feel... My duramax has a transmission setting for towing that it will down shift just like a standard trans to use the engine for braking... It sounds very different to hear it downshift and the engine rev up just like you were doing it with the clutch... (great for towing a big trailer like we have)

 

[hanoverphist]

my older civic does this as well, i used to pop it into neutral to see if it was the trans or brakes dragging me back. it has a delay tho, so i just make sure to tap the gas once in a while if im on a slight down hill. that will keep me rolling along usually. weird thing is, my ram 1500 with a manual trans will do the same thing. i regularly travel to cottonwood, and there are many hills between there and the valley. i usually pop it into 4th when going downhill so i dont need to use the brakes at all, but even then its like the throttle has a bit of gas lag, where it keeps speed. then, a bit later, it will noticeably slow down. i also tap the throttle once in a while to keep it at 65. if i dont, ill be doing 55 downhill pretty quickly. i think its more a throttle action than the transmission tho.

 

[Zenmervolt]

my older civic does this as well, i used to pop it into neutral to see if it was the trans or brakes dragging me back. it has a delay tho, so i just make sure to tap the gas once in a while if im on a slight down hill. that will keep me rolling along usually. weird thing is, my ram 1500 with a manual trans will do the same thing. i regularly travel to cottonwood, and there are many hills between there and the valley. i usually pop it into 4th when going downhill so i dont need to use the brakes at all, but even then its like the throttle has a bit of gas lag, where it keeps speed. then, a bit later, it will noticeably slow down. i also tap the throttle once in a while to keep it at 65. if i dont, ill be doing 55 downhill pretty quickly. i think its more a throttle action than the transmission tho.

That's probably the "grade logic" part of the transmission's electronic controls. Many automatics will "notice" an extended downhill grade and engage the lockup clutch to provide more engine braking on downhills.

ZV

 

[thomsbrain]

My Accord has very aggressive grade logic and will drop 2 gears if necessary on downhills. The downshift into first coming to a stoplight is also noticeable sometimes.

 

[clarkei]

The first vehicle I ever owned that downshifted while highway coasting downhill (engine on in drive) was our 2012 Civic. When I took it back to the dealer to have this "problem" looked into, I was informed that it was now a built in feature required by the Ministry of Transport no less. With my eye on fuel economy this did not please me even though we got 45mpg on our trip into the BC interior. I have learned to coast in neutral (engine on) in our 2014 Civic (that replaced the 2012 when it was totalled while parked), but am still suffering the nagging doubt as to whether this is causing wear in the transmission somehow.

 

[Vdubchaos]

I thought all cars with autos did this.

Correct

You really notice it when you go from Manual car to Auto.