This says it better than I did originally^^

 

Well SigIS350 I guess we are the only ones with this problem. I thought maybe a transmission oil chang might fix the problem but it seems that the transmission is a sealed unit. Unfortunately the Lexus dealership I go to is big on NPF (no problem found)

 

I have been having a similar problem. When I am cruising with RPMs around 2000-2500 and I try to step on the throttle to pass someone for example, the RPMs jump up to near red line and I have to let off the gas to avoid blowing my engine. The best way I can explain it is that the transmission is disengaging from whatever gear it was in and not engaging a lower gear to give me the power to pick up and pass the car. Instead, the transmission seems to be disengaging from the current gear and keeping it in nuetural (instead of engaging a lower gear for more power) which causes the engine to rev up near the red line when I step on it.

This problem occurs intermittently, however I know it is not normal and has concerned me since I first noticed it about 15,000 miles ago. I took it into Lexus right away and they said they couldn't do anything about it since they could not replicate the problem. My car now has 58,000 miles and this problem still occurs from time to time in the manner that I described in the first paragraph. The powertrain warranty expires at 70,000 miles, so I need to find the problem and have it fixed while it's still covered, or I will be paying mucho dinero!

BTW- This problem I am experiencing occurs while in manual AND auto mode!

 

No need to worry about blowing up the engine. It's a near impossibility with the rev limiter. As long as proper oil levels and temperatures are maintained, you could literally hold the throttle wide open in neutral and bounce off the rev limiter all day long.

 

i have an 09 is250 awd and my car just started doing this. i would be cruising on the freeway anywhere from 30-60 and step on the gas to pass a car and it downshifts fine and accelerates fine bt then never upshifts the tach will just sit at 4500-6000 rpms. i have tried tapping the gas pedal, hitting the brakes, bt usually it takes bout 5-6seconds with the rpms just sitting there before it upshifts. i do always drive with the car in power mode. i have tried turning it to norm and back bt the car seems to do it once a day on avg.

 

turn power mode off...