Ericspyder

Hi, I have 2006 is350, it has 70Kmiles. When I do hard brake, the car is stop and sudden jump forward right after.
But if I stop gradually slow, nothing happen.
Is it something wrong with the transmission? Why it's happen like that? Does it happen to any body?
Thanks,
Eric

Aspect

can you post a vid? Sounds like engine braking, are you using manual mode?

Ericspyder

It's not jump, wrong word. It's just act like we shift to drive when the idle is high.

Ericspyder

No, I'm using D mode.

bazzle01

Gerarbox changing down, is slower than your stopping speed.

Pham25

Are you using ECT PWR mode? The car usually does this in power mode, it has aggressive downshift and holds the gear in case you need to step on it again itll already be in gear for you to take off.

Ericspyder

Let me check if it is on PWR mode. Thanks.

WhatYaGot

Bad motor mount or trans mount?

cheezz

I think you are referring to brake / traction problem. Does it do that when you make a complete stop? The engine idles high at 1100~ 1200 RPM until the engine gets fully warmed up. It does that especially in the cold, making this car difficult to drive in the snow / icy condition. The car has a lot of power on the rear wheels and the rear brakes aren't beefy enough, so lightly pressing on the brake won't be strong enough to stop the wheels from turning. You'll need to either push the brake harder or set it to neutral to disengage power going to the rear wheels. You can put it back to Drive when the light turns green or when you need to move. Another option is to get snow tires both front and back so that you get better grip to keep the car stationary. If you drive the car after it's fully warmed up then you shouldn't run into this issue as the engine will idle at 600 rpm. At 600 rpm it's easy to keep the car stationary with light brake on the pedal but the 1100~ 1200 rpm you need more brake power or better tires or set it to neutral.

Ericspyder

I forgot to tell the beginning, I changed transmission fluid a week ago, by drain and fill. It's start that problem since. I call dealer and they said maybe I did under fill or overfill, the symptom is familiar with transmission fluid too low or too high. I made appointment with them tomorrow. Will update later.
BTW, I check the ECT is at normal mode, I tried to use PWR mode, the problem was worst, at ICE mode the problem still there but less.
That happen when my car is warm up. The idle at normal term.
Thanks,
Eric

jr4div2

Did you measure what was drained and only put back in what was removed. There is a method to doing a proper drain of the tranny that simply dropping the plug will not accomplish. If you only drained what came out after dropping the plug, you only removed, I believe about half of the transmission fluid. If you added back the capacity of the transmission according the the specs, you overfilled the heck out of it.

Ericspyder

Yes, i did refill exactly what came out, but i think my mistake is the temperature. I drain it, refill the same amount, turn on the car, shift gear to all position and back to P, drain again and refill. I did 4 times like that, I think the fluid came out was expand than the fluid came in. I think now it overfill about haft quart or more than that, cause my transmission judging.
Thanks.

Gville350

iTrader: (10)

Yeah, sounds like a trans fluid amount issue. Probably too much fluid. If you watch this video, do the sequence correctly, drain the excessive fluid out of the drain plug, it should hopefully fix itself with HOPEFULLY no long-term consequences.

You Tube

Ericspyder

Yes, I think you are right. Thanks for the advice.