FrankMazzarella

I have a 2004 civic lx (auto) and i noticed that while driving if i shift into neutral and rev hard the car actually pulls forward.

I know the hondamatic transmission for the 7th gen is awful but why does this happen and what should i do

MindBomber

Pulls forward like a gentle roll or like its actually in gear?

FrankMazzarella

its a noticable tug, the speed increases. only at high rpm's also.

I tested this while i was not moving by parking on a flat surface shifting into neutral and reving, nothing the car was stationary. but when going about 35-37mph is when i tested this. the car increased to 40mph.

gearbox

iTrader: (95)

that is a problem. either there is too much trans fluid, or defective clutch(es) which we all know about. so if the fluid is fine when you check it hot, then its an internal problem that requires rebuilding. so long as it still drives, i wouldnt worry for now. but check the fluid level just in case (warm up the car by driving for at least 30 mins thru all the gears, park on flat ground, leave engine running and trans in park, check the dipstick level several times to get a good reading. it should be at the max line).

FrankMazzarella

thanks for the reply. i will be sure to check for that and i will repost back probably 2-3 hrs from now.

thanks again. but hey, if i do need an $1800 rebuild how much do you think a good shop would charge to convert me to a manual?

MindBomber

If the car doesn't move when its stationary I wouldn't be concerned, there are countless variables involved with the car increasing a speed slightly while moving. I'd suspect that the decrease in friction allows the car to increase in speed slightly, before it starts slowing down.

Now, if the car was moving in neutral while parked on a flat surface then I'd be concerned.

FrankMazzarella

well im not too concerned but if it is a big problem then i want to take care of it asap.

back to what gearbox suggested. i drove the car for 30 mns in all gears and when i checked trans fluid i found that there is about 3-4 mm too much fluid. thats a very small ammount but should i be concerned?

thanks (also, car has never slipped and shifts like butter)

MindBomber

Drain the fluid to the proper level and see if the slight surge still occurs, this has me curious so I'm going to go try this in my car and my truck.

gearbox

iTrader: (95)

yes be concerned. just drain some fluid out and recheck. too much trans fluid can lead to bigger problems later.

BlueEM2

iTrader: (1)

Shouldn't really be revving the car high in neutral anyway?

FrankMazzarella

your absolutely right haha i waiting for a comment like this. I actually heard of a car doing this and decided to try mine. bad luck i guess. Im going to drain the fluid maybe tonight or sometime tomorrow. I will let you guys know of the results. also gearbox says to have fluid ON the max line. Is less ok as long as its between the marks?

btw MindBomber let me know how that goes. and again, thanks!

gearbox

iTrader: (95)

a little less is okay.

ExistEvolution

too low and you can put hotspots on the clutch packs or was it the flex plate, you should be right at optimum level with fluid, rule of thumb though you would have to have a high excess if you're a hair over the optimum mark on tranny dipstick it won't hurt anything, too much fluid and you would smell a burning sweet smell and it would smoke. You could also blow out tranny seals with too much fluid. If you're going to drain it, i would say just drain and fill it or if you have the money just get the tranny fluid flushed.

FrankMazzarella

ok i removed some fluid. i took out very little. on the dipstick it is slightly above the middle line, which is fine because it is still within the lines. unfortunately this made no difference. but at least it rules out the fluid possibilities.

so what is my next option? thanks

ExistEvolution

so your car drives forward or just rolls forward?

FrankMazzarella

this

MindBomber

Update!

I changed my trans fluid yesterday, and I was a little bit high when I first refilled, but before I drained a bit out I tested this. The car will pull forward with to much trans fluid, and draining it down to the proper level will solve the problem.

FrankMazzarella

what is your car and at what rpm were you pulling at? also what is your fluid level because i am between the lines. was it enough to suck you into the seat?

thanks for helping me out with this one guys. ill get down to a tranny shop eventually haha

ExistEvolution

ok i read that but was it consistently picking up speed or just jump to 40mph, if it just bump to 40 mph there is nothing wrong with your car, its the people that can keep driving in neutral that have issues.

MindBomber

I just tried cause I knew my fluid was a bit high, and thats what gearbox said the problem was cause by. I wasn't scientific about it..

FrankMazzarella

idk how much speed it would pick up i didnt hold it long at all, nor do i plan on trying it again

lazlong

Sorry, I would have posted this days ago if I wasn't camping for the last 5 days. (It was great by the way)

UfailV8

You could have a malfunctioning throttel body/throttel body sensor. I had a 1999 Jeep Grand Cherokee that had the same symptoms.