jat0223

iTrader: (1)

I've been driving my '11 isf for two weeks already and have noticed some things that I'm not sure are normal.

1. I usually drive in very heavy bumper to bumper traffic. I notice that this car has a lot of engine brake. As soon as I release the accelerator to coast at very slow speeds (below 15mph), the car starts making the usual noise that a manual car does when engine braking. The car doesn't coast freely and I can feel the engine brake. Is this normal?

2. While in stop and go traffic the trassmission is not as smooth as some people mention. sometimes it hangs too long in a gear and sometimes it even jerks the car a bit.

3. I've read that the car is supposed to be quiet at lower rpms, but mine is not that quiet. It has a nice low rumble. Sometimes it does gets a bit droney (if thats a word). I don't mind it, but just want to make sure that all this is normal.

Thanks

MisterSkiz

iTrader: (2)

When you experience issue number 1 and 2, what type of transmission mode are you in?

If you are in "Manual" mode, the car will feel a bit jerky slowing down as the torque converter is locked.

If you are in "Automatic" mode, then you might have an issue. You will also notice a "feature" in Automatic mode that if you punch it and take off, then let off the gas really quick, the car will stay in the same gear for you, so that you can take off quicker. If you dont put your foot back down, the car will eventually shift into the next gears.

The car does drone a bit at lower RPM's however you have to really listen for it. Its a bigger V8

jat0223

iTrader: (1)

I'm in auto mode when I experience this. I've noticed that if I let it coast long enough, the engine eventually releases and coasts freely. For example if I'm going at 30mph and release the accelerator, the car feels like is engine breaking and then it like releases and I feel the jump in speed when it does.

MisterSkiz

iTrader: (2)

usually in a normal auto transmission the torque converter only locks when you are crusing and using light throttle (to help with gas mileage).

are you in sport mode by chance as well?

if you are very concerned take the car in and go for a ride with the F Champion tech. they will be happy to help you.

jat0223

iTrader: (1)

Perhaps that's what's happening. Since I'm in stop and go traffic most of the time I'm always using light throttle. I'm not in sport mode though. Actually when I engage sport, the trassmission becomes smoother. What is the f tech? Thanks for all your help

MisterSkiz

iTrader: (2)

Every dealership has one sales individual and one tech that received special training for the IS-F. They are known as the "F" "Champions" at the dealership because they are the only ones who should be dealing with IS-F issues.

By all means, take the car in and have it looked at. They will probably scan the computer for any trouble/error codes that might be popping up, etc.

At the least you can have it documented that you brought it in for the issue, in case anything pops up later.

F4Fast

Sounds like normal but i have a question. Did you get the car used? Or new? Previous owner may have driven your car different and the tcm learns that driving pattern. Now that its going through different driving by a different driver its clashing and is actually tying to learn the new pattern to suite the driver and car better. You can go to lexus and get it reset so the tcm learns your driving style. Just make sure when they do if you decide to do it, get on sport mode, and punch it, hard. Hope this helps and good luck

jat0223

iTrader: (1)

Thanks for your help guys. I got it with 5k miles. The car was previously driven by the owner of the lexus dealer.

MisterSkiz

iTrader: (2)

Just take it in, I'm sure you will feel better then

I drive my F hard all the time after its warmed up. Its just fine

LBmtb

I may be alone in this but when I'm in bad traffic (happens a lot in socal) I tend to put it in snow mode. Everything becomes super smooth.

VtotheJ

iTrader: (2)

^Good tip, I should try this in traffic

jat0223

iTrader: (1)

I'll take it in to see what they say. I'll try the snow bottom as well to see what happens. I wish I could drive it hard most of the time as some of you do, but here in the city is almost impossible.

Thanks for everything guys.

iH8RICERZ

iTrader: (3)

So what exactly happens when you switch between different modes? Sport mode - Accelerator feels more responsive, Normal mode - Feels like eco mode, haven't tried Snow mode... as soon as you hit that button, does the computer change settings on the accelerator or is there more to it?

LBmtb

Don't know if there's more to it but the car accelerates very gradually, throttle is much less responsive, and it tries to stay in as high a gear as possible. This makes sense for snow because the priority is to not lose traction.

redsvt02

I know your question has been answered but to further reassure you the "engine braking" feeling is normal. My F does it and a few other Lexus sedans I have owned did this too. It is completely normal. In response to the second question, your car is fine. From my research these cars are equipped with an adaptive 8 spd trans, thus meaning the car picks up on how your driving and shifts accordingly. I don't know why it would hang a little longer in first in traffic but mine does it too.

In summary, your car is mint...relax and enjoy this fine automobile.