Guys lately i have been noticing weird transmission shifting behavior where it's shifting very sluggish and at times it won't upshift....For instance in auto mode car is in 2nd gear and i am trying to accelerate....RPM will go all the way to 6k or above without an Upshift...Sometimes i have to manually shift it to get it back to normal shifts.

Another behavior which is very much Reproducible....At 80 let's say i step on it on auto mode....So it downshifts to 6th, now during upshift going from 6th to 7th...RPM's Jump about 500 RPMs before coming down to Normal RPM range for 7th gear.....I''ll post a video soon

Let me know if other F owners noticed this.....My F has about 26k miles (Never tracked or abused)

 

Do you have the sport mode on in the first situation?

 

Normal mode

 

Link to the video:-

http://www.youtube.com/watch?v=fzADi...e_gdata_player

 

sounds like the tranny is slipping but i could be wrong

 

i hope not....i'll bring it to the dealer, lets see what happens

 

Watching the 7-8 shift in your vid. My F also does that rev/slip on occasion around 70-80mph under light throttle. Could be auto/M or Sport/Normal - doesn't matter.

 

Sounds like a fluid level problem in the gearbox. Did they disconnect the cooler lines when they did the engine? They might not have topped off the gearbox correctly.

 

http://www.lexusfforum.com/forums/sh...t=transmission

I don't know about the 500 rpm blip, but not wanting to shift out of second has happened to many people. Check out the above link.

 

Correct, mine doe the second gear thing 4 to 5 times a week! ARRGGGG!

 

Lance you may be correct...Since the issue started right after they did the engine work....Should i bring it to their attention?

 

Sure. Sometimes they need to be reminded of the car's history.

 

I have a similar problem. My car does the 500 RPM jump only when going from 4th into 5th, and only when the car has been sitting with the engine off for over a couple of hours. It does it only the first time going into 5th, then it won't happen again until the next time the engine is off (for another couple of hours). This behavior leads me to believe that it's indeed something related with the tranny's oil level, since it won't happen again once the car has been warmed up, or driven already past 5th gear. My car has never seen the dealer for anything other than regular service or warranty work (rearview mirror, blown subwoofer, faulty ML touchscreen, and tach needle issue), and I purchased it brand new back in June 2008.

I took the car to the dealer for this issue, and both the mechanic and his supervisor agreed that this was normal behavior. I told them how come this is normal if it's been happening since last month, not since the beginning... they failed to answer that. I made sure that they entered my concern in their system (which is nationwide), so if I have a tranny problem in the future my concern was already documented.

Off the record, the mechanic said that he did notice the problem. He also said that it'd be really hard for Lexus to aknowledge the problem because they'd have to start an investigation on all IS-Fs, and if they confirm the issue with the tranny they'd have to replace it completely, apparently this tranny needs to be replaced in full. The warranty is good for 7 years, so let's see what happens.

 

Problem arised when car turned 17k miles...although dealer had performed some engine work and noticed this strange shifting behaviour right after the repair.

I'll bring it to the dealer this weekend.

 

^^^ Interesting, post the results (and reason of the problem) after your visit to the dealer.