Lexicon14

Hi all

Proud owner of a new 2014 Lexus IS 350 F Sport and couldn't be happier. And this is my first post.

Had a question regarding my car. In the morning, after starting the car, I notice that after accelerating a little, the car jerks. It only happens one time in the morning and not during the rest of the day.

Does anyone know what's causing this? I'm hoping this is a temporary phase of the car and nothing too serious.

zabone

iTrader: (2)

The whole morning?

It would be normal if the car isn't warmed up yet.

The transmission shifts a little rougher. Totally normal.

However if the car does it your whole commute then it's not normal

AdvanSLF

my take is because the engine hasn't fully warmed up yet, and so the performance (upshifts) like zabone said can be rougher. think about it from a more logical point, when you wake up in the morning, do you immediately feel refresh like you can concur the world? no or course not, people usually need coffee, or breakfast, or something else to kind of break them into the morning. same goes with the car. it hasn't been used all night and has cooled down. in cooler to colder conditions, the car won't be as smooth until it's warmed up to operating temp.

KumaF

I had this happening to me druing the first few days of driving. Slight jerks when starting and stopping, most noticeable in slow traffic. Like the others said, once the engine warms up, it's gone. I haven't had it since then, now I can go WOT right after starting the car and no jerks what so ever. so I figured it was caused by a combination of factors 1) new engine and transmission; 2) ECU just started to learn and adjust shift points; 3) cold fluids in the morning.

From my experience, it is temporary and nothing to worry about.

jay631987

if it is from first to second gear then its because those gears are not on the same "rod" in the transmission...forgot what is the correct mechanical term...that is normal though...the reverse and first gear are on the same "rod"...

KumaF

You mean coaxial?

jay631987

lol not sure...maybe shaft?

Slust

The 2IS I had used to shift hard in the morning. Someone told me to let it warm up long enough for the idle RPMs to settle down (usually 30s) it would shift better and it worked. So unless I was in hurry I would warm up till RPMs went down and it would be fine. The days I didn't that first shift from 2nd to 3rd was always a jerky one.

If that is the behavior you are talking about, give it a try. If it's not than we are talking about two different things.

Lexicon14

Thanks all. After reading al your post, I felt a little better about it. In fact, this morning I let the engine warm up for maybe an extra minute and poof!!!!! NO JERKING! I think I was more surprised since none of the other cars I had ever did this before.

Anyway, I'll keep experimenting with it every morning for the near future. In the meantime, thanks for all your advice!

zabone

iTrader: (2)

Really? Every one of my cars have done this. In fact this car is the one I have not noticed too much. The 8 speed is really smooth

Fizzboy7

Never go WOT right after starting a car. It ruins the internals.