Last night i put my foot down on my accelerator on my IS250 Auto and after speeding a bit I had to come to a stop at a traffic light. when i stopped I felt the car jerked for a second or two like it was shivering. I'm wondering what this was and also after putting my foot down sometimes I notice a burning kind of smell that goes away after while I dont know if its my car or not.

does anyone know what it can be?

anyone? would love to hear your opinions on if this is normal or if something is wrong. it doesnt do it always only once in a blue moon.

Hi,

I have had the same thing happen to my 250 Auto. Stopped at traffic lights. foot on brake pedal but the car suddenly launches forwards briefly. Need to step on the brake pedal harder to stop it. Quite scary the first time it happened but just like yours it only happens once in a while

On one occasion I put the auto box in "N", applied the parking brake and the same happened but car didn't move forward thanks to the parking brake but did "shake" for a second or two

Did ask the dealership to investigate at the recent 20,000 mile service but they found nothing wrong

No burning smell on mine though

I'm having a bit of a wild stab in the dark here, and someone may correct me, but I believe that if you lift off the accelerator when you slow down to lights and junctions, the fuel is cut off to the engine. When the revs drop sufficiently the fuel starts up again as you idle or press the accelerator once more. If you blip the throttle as you slow, or speed up and then brake sharply, there's a surge of fuel to the engine and then an abrupt cut off. Sometimes the engine revs drop right down to almost the point of stalling before the ECU send another shot of fuel to fire it up again, resulting in that shiver.

Did you have the aircon on? If you come to a stop and the AC compressor is not running, if it then starts up the revs initially drop and thenincrease slightly and this would make the car shudder/move forward when it otherwise wouldn't.


If you are in N the car shouldn't ever move anywhere no matter how high you rev the engine

Sounds like a sticking launch contol issue particularly if you are on an up-hill incline.
Tel