mooretorque

p1f, let me try to clarify: lil4x has it mostly right. The RX will not upshift into 4th until transmission fluid temp reaches 176 degrees F. This is primarily to light off the convertor more quickly. Apparently there is also a temp limit for upshift to 3rd, but it's lower and in warm weather you may not run into that limit. However, it's not going to upshift even at redline till the temp is up (which is where lil4x is mistaken), according to my service guy.

Nowhere is it written that you have to drive out of your driveway and immediately rev the ***** out of your RX. When I drive wifey's RX, even when weather is quite cold, I'm in 3rd in about 1/2 mile of gentle suburban neighborhood driving, and in 4th within a mile. Unless you live on a freeway, you shouldn't have any problem keeping up with traffic at 3000 rpm in 2nd, much less 3rd. Since 4k rpm is the breakin limit, you've got even more cushion. But even in both my well run-in vehicles, I don't ask for more than 3000 until I've seen the temp gauge move up at least a couple of notches.

As far as TSBs, try alldata.com; you can get a list, and if you want to spend the money, they'll tell you what the TSBs actually say!

DJ SprinklesNJO

hey same thing happens to my 99 rx. asked the people at lexus awhile ago but dont remember their answer, so obviously it wasn all that threatening to the car. buti can tellu this. i guess its ok. just dont drive so fast till it warms up, thats what i do. also i have a 99 es. and when cold it does not do that. oh and another thing, i once got a 2000 loner rx. (just fron wheel drive) and when it was cold it did not do that. so maybe it has to do with the all wheel drive or transfer case. ???? who knows

wow

Check your car owner's manual, my 91 ls400 owner's manual states: "while the engine coolant temperature is low and the vehicle is traveling at low speed, the transmission will not be shifted into the overdrive gear even with the overdrive switch on". Noted, the max allowable speed for "2" is 79 mph, and the "L" is 48 mph. This means you can do 70 mph in 2nd with no problem...

kb2yza

That is normal ... and like it was said you shouldn't really have to be in 4th that fast but if you do (when your in a hurry) the engine will redline until the computer senses that all the temps are at their correct "running" position. Basically you car is shifting at a higher RPM, this will let the engine run faster, heat up faster, and run ecnomically and enviromentally better. on the TSB issue I will check Mitchell on Monday (6/17) and post what i find out for you. Till then, Enjoy.

kb2yza

Check Mtichell today nothing found on that issue their was one on a Shudder during shifting from 2-3 If you would liek a copy just post up and I will post it up here

whitels

Like what most people here said, take it to the dealer but insist that you leave it overnight out in the cold parking lot so they can test drive it first thing in the morning. You may want to be there during the test drive to point exactly to the test driver the problems you are having - else, it'll check out okay!

My wife's RX does this but not as severe as in your case. Warm up period is about 15 seconds, then drives downhill for about a mile from home. First quarter mile she is on 2nd gear (you can feel the engine brake effect) going downhill, then it upshifts to third, and fourth, like it is normal. By the time she hits the freeway (1.2 miles away) her RX has shifted to 5th already with the temp gauge just barely above the 1st line. Average speed is about 25-40 mph before hitting the freeway.

My GS also does this thing, won't upshift to 3rd during the first half mile on cold 62 degree mornings. After traveling for a mile or so, it's ready to upshift to 5th.

I think your RX oughtta be seen by Lexus.

KISMETSDAD

I have been reading the repair manual. I recollect from the transmission section that the water temp is fed to the control module for the transmission and it prevents upshifting to OD until temp is appropriate. I dont have the manual to review at the moment. the shop manual has ~200 pages of transmission troubleshooting

DJ SprinklesNJO

i just noticed today dribing on the highway that it seems like my transmission is slipping. around 60mph to 70mph every so often i get this bumping sensation from the car. and it doesnt matter if im accelerating or crusing or my foot is offr the gas, what the hell is wrong with my RX