Jewcano

iTrader: (4)

At least I think it's a transmission problem.

Car has mid 155k miles, 01 GS430. Did a semi recent transmission flush (I know I know we aren't supposed to do that).

Here is a breakdown of the issue I'm experiencing. I cannot replicate it and it seems to happen randomly whether the engine is warm or cold.

When driving various speeds, usually happens more predominantly at lower speeds but have had it happen at 65mph, the car 'jerks' (feels like the transmission disengages then re-engages). I get no engine codes, nothing. Has anyone experienced a similar issue. Most transmission threads here usually have a code associated with the issue or have an entirely different issue, but I can't find one that reads like mine.

Any help would be appreciated.

Sampak

Does the RPM swell up when it "disengages" momentarily? Otherwise sounds like more of an engine misfire/backfire or some other weird issue, going off on what you wrote.

Jewcano

iTrader: (4)

Hrmmm no i don't notice the rpms jump up. I'll keep an eye on that though. I just did a trip to the grocery store and it drove fine (60F outside).

Though I have been getting slightly worse MPG over the past couple years. Granted I went from mostly highway to mostly small city trips, but even with the 19mpg has dropped to bout 17.5. I've also been using either Mobile One or Royal Purple for oil changes. Has anyone else had a misfire issue like this? And would that not bring up an engine code?

MrHimbert

i notice when i come up to a stop, and i am at a slow roll, or go into a turn, i will hit the gas and nothing will happen for a solid second, it almost feels like the transmission is out of gear, and is confused on what gear to put it in. so it finally reacts when i give it more gas, and jolts into gear. No codes or anything as well...not sure if my transmission is starting to go or what. Its not everytime as well. could be a similar issue? who knows.

Jewcano

iTrader: (4)

^Mine doesn't have a pause during any of those situations though. It's usually in a straight line after having already applied acceleration. But it does 'jerk' for a sec or so, then continue like nothing happened.

RXGS

iTrader: (2)

I have this thing where every onc win a while (like one a month) it will shift from first then go into second, but the transmission almost forgets to change, then it realizes and jerks. The rpms keep going up as if I'm holding it in manual more or something. Only does it going into second and its so rare. I have no idea but no codes or changes in gas mileage ect. Tranny pan was dropped at 35. I just did a drain and fill at 78. In the service records the previous owner noted something similar with like 15k but the dealer said everything was fine on the report. I'm assuming its just the way the car is and has a hiccup once in a while. Fluid was good as well not dark and not burnt smelling.

Jewcano

iTrader: (4)

^That sounds more like a delay in engaging into gear. This engages fine no delay, but randomly jerks. No particular speed, no particular weather, happens when cold and warm, though moreso when cold.

It'd be nice if someone local could ride one day with me to feel the jerking, because it's difficult to explain.

Jewcano

iTrader: (4)

Bringing this back up.....anyone have any ideas?

Still happens randomly. Can't figure out what it can be....perhaps from the tranny flush something bouncing around inside the transmission?

repugnante

check your tranny mount. When mine was split in two it would do what you are describing....

Jewcano

iTrader: (4)

^It would do it randomly as well? And at random speeds? I notice it'll do it at low speed between 1st and 2nd gear, sometimes it'll do it around 40-50mph, rarely on the highway at 65+ though. Generally does it on the lower band of speeds.

aneidiaz

I've read everyones posts. Given no codes or major problems, this can all be our transmissions getting old. We need to take care of them by driving the car smoothly and getting tranny flushes every 15-20k miles now that these cars are older. I'm riding in a 01' and I have no codes. But I tend to notice the car do a little of everything you guys have discussed on this. I just hit 100k in it. Bought it in February 2012 with 76k. I have done a transmission flush a few thousand miles back. For the most part the car is GOOD. No complaints with funny here and there incidents. Considering MY car is getting old and it's been my daily driver pretty much since I bought it. Tranny flushes guys and no horsing around... The older they get, the more they're prone to problems. If you take care of them and correct anything that needs to done, it'll last you 300k!

aneidiaz

Just call your dealer and get an exact quote from somebody and take down they're name along with the date and time this call was made. Take your car in to your local Lexus dealer. I know some people on here tend to say they over charge, stealership, etc.. Hell, even I will say they're a little expensive because I WENT THERE too. Smh But they will do what's necessary and check anything out once the car is lifted up. Especially if you go in there expressing this problem your having allot. I got a tranny flush at the dealer and they charged damn near $300. YES I KNOW, I GOT HEAD CRACKED But I haven't felt that late jerky feeling from the transmission as much AFTER I went to the dealer. Not the same when you go to a minor certified mechanic at a smaller shop. Lexus has the tools to do it properly.

aneidiaz

Also check if your calipers aren't seizing up. All around I'd recommend checking. If they're say for example HALFWAY seizing up every time you brake the car in motion, you won't even notice what's going on down there, once you brake momentarily and hit the gas, the calipers can be still seized up and take a few seconds to release again while your still hitting the gas. Since your not even thinking that, that can be the momentary "jerk" to the car. Don't only assume in your head it's the transmission. Just saying check around everywhere. Doesn't hurt. I had my front left caliper seized for damn near 2 years before it got noticeably bad. I changed it and the car thus far got smoother. Bearings should be checked too. That can "jerk" the car as well if they're in TERRIBLE shape. Hope your problems clear up and you get peace of mind bro!!

wbmx1981

This happened to me and my ATF T-IV fluid was too low. Make sure you have enough fluid. No ATF means no go, sudden loss of acceleration, etc.

Lukas99GS

Mine also shifts weird from a stop or going around corners, kinda jolts unless I press the gas just right, I've heard that's common though on our cars, like a little hesitation wondering if maybe a throttle position sensor could fix this