I've got about 126k on my gs300, and the transmission has gotten worse and worse in the last 10k miles. usually the first issue is that if not warmed up for a while, the car would not shift from 4th to 5th unless i gave it a harder throttle. i would sometimes even have to put it in manual, drop it to third, and then shift back up to 5th just to get it to go. (number said it was in 4th though)

anyway the new issue is harsh jolts into gear from 1st gear. some harsh shifting to 2nd sometimes, and the rest are flawless. if driven very lightly, after the initial jolt when hitting the gas, i could get the rest of the gears to shift smoothly.

it seems to hesitate a lot, and the car even feels very sluggish and unsure. its like the car isn't sure about what gear to put it in, when rolling from a stop. sometimes i have to punch it around a corner just to get the damn car to move.

i was thinking that i would do some sort of tranny flush or something to start. but my second thought was that maybe the transmission solenoids might be sticking. i know i had to replace one of those on my Ex wife car (ford fusion, 120k miles).
the only thing about that was her car was giving that code off. my car is not giving me any flashing lights or any warnings or codes. (not that i have plugged it in randomly, but wouldn't it give me some type of dome light?)


Any thoughts or tips on what to check?

 

Try a drain and refill.
2quarts Toyota IV ATF .
Always seems to do the trick.

Don't flussssshhhh it.

 

Hook it up to a scanner/reader, and check if any codes are pending. Sounds like a solenoid issue. I'm replacing my Solenoid C real soon, just got the part from Sewell. Seach P0763 here and read about it.

 

thats what i was thinking as well. Would the trans acting up like this cause terrible gas milage? I drive about 26 miles to work, and usually i only use a small sliver of a needle to get there. Today i literally used a half of a quarter of a tank. something is definitely wrong. My bike chain snapped and put a hole in my case and this is my only transportation at the moment. FML. Would it throw codes without any check engine lights coming on? i will plug mine in and hopefully i get something that will point me in the right direction.

Odd that flushing the whole system would be a bad thing. but i will do this along with a new mesh filter for the intake, clean the throttle body and MAF sensor. Not sure what else i should check to make sure that everything else is in place.

What about valve adjustments? could the VVTI be messing up?

Thank you guys, im freaking out so much im about to buy a new car lol

 

The solenoid issue typically plagues the 98-00 models. I haven't seen or read of an issue with the 01+ models. Do you have any service history of the tranny? Have you changed the fluid ANY since you owned it? My old car tranny wouldn't shift out correctly if the fluid wasn't warm.....but that car had 250k miles on it. As far as drain and fill, I'm able to get a constant 3qts out when I drain because I place my car on high incline ramps to drain. Most people only get 2qts out each time.

 

Ive never fully flushed it since owning it the last 40k miles. i was attempting to flush it before with a few quarts. but thats about as far as i have ever gotten. I want to try and flush more out but people keep saying not to do a full flush. i get why they are saying it, but at the same time im sort of feeling like maybe it needs it.

 

just pulled the MAF sensor. it was very dirty. cleaned it all up and put it back in. hopefully on my drive home from work a few things are running better. but i definitly have to figure out my trans problem asap.

 

A real flush with a pressurized machine is good. Slog with a filter change too. I'm gonna add a magnetic inline filter onto mine.

Maybe adding an inline filter would help clear yours up as well. They're cheap and definitely worth a try

 

I always hear people say that the complete FLUSH on high mileage is bad and can break up sludge chunks and all that. Is there anyone on here that has actually done the full trans flush on a high mileage GS and can comment here?? Because others say the way the Lexus trans is built that its actually ok to do the flush.

 

Solenoid C (Code P0763), search the forum.

 

Im having a similar problem. My 01 doesnt want to shift into 5th gear, and when it does, it shifts very hard and the car jumps forward. Going to try a drain and filter change. Ill let you know how that goes.