Hello All. First off, pardon this question in advance. I hope it is something super obvious, but I don't know a thing about cars, mechanically. I could probably rewire your entire dash, but I'm lost when it comes to engines and transmissions.

I have a 2009 IS250. Bought it certified pre-owned with about 65k miles. The past few weeks I noticed that when I accelerate from a stop, the power doesn't seem to correspond to how much I'm stepping on the gas. Seems sluggish, or delayed almost. It feels like the car is hesitating. Sometimes it also feels like the power "catches up", and all of a sudden the RPM's and acceleration kick in, throwing me back in my seat a bit unexpectedly. At first I thought it might be dirty fuel injectors. Used one cycle of your typical gas station injector cleaner that you put into your fuel tank. Might have been my imagination, but I thought it was working for a bit. Now, at the end of that tank of gas, it feels like it is back (again, maybe my imagination that it was working in the first place).

So, I'm obviously concerned that this is my transmission. I've only had the car for 6 months and I don't drive all that hard or far. I just had a CV joint replaced not too long ago, and they supposedly looked over the entire car, so I'd imagine my transmission fluid levels and air filters are ok. Any suggestions? Crossing my fingers that someone will tell me something simple and call me an idiot for not checking already. This is the one time I wouldn't mind looking like a fool for not knowing something simple.

 

First thing first, system reset (just like turning off your PC). Disconnect the battery for 15 minutes, and then re-connect. This will force the car to re-learn shift points, your overall driving style, etc etc. After reconnected, let idle for 10 minutes, then go out for a drive like you normally would. If you drive like a grandma, then drive like it. If you drive it like you stole it, do so.

Report back after this testing to see if you have any improvements whatsoever.

 

Good tip. I never would have thought of that, so big thanks. I'll test it out this weekend and write back. Also, maybe this will help out with my rather poor description: When I step on the gas from a start or if I'm coasting under 20 MPH, the RPMs will shoot up, but power doesn't seem to hit the wheels right away. Sometimes it feels like it hits all of a sudden a second or two after I actually press the gas pedal, jerking me forward as it comes unexpectedly and delayed. Other times it feels like it just very slowly catches up on a much smoother level, albeit slower than I would have expected. I know the IS250 isn't exactly as sporty as it looks, but even my '04 3.0 X5 was more nimble.

I'll give that a go and report back. Thanks again!

 

^No problem. Hopefully the full system reset will help things re-learn and get you back to "normal". I had to do this once after I had my car in for the cam gear recall, and the dealership had the battery disconnected. They fixed everything, reconnected the battery, and tested the car out (put a couple of miles on it to ensure the car was functioning fine). So during that SHORT test drive, the car learned that driver's habits...not mine. So I forced the car into re-learned my habits, it was all back to normal.

GL!

 

do you have an auto or manual? because if its auto and your shifting with paddles that lag will never go away, that's the only complain I got on my is the slow shifting