Hi everyone. I'm new to these forums. I've been searching for the past half hour and haven't found an issue quite like mine here.

I drive a 98 Lexus gs 300 w 160 k miles. Recently while driving DOWN a very steep mountain I slow the car from 75 to 60 mph (traffic). When I go to give it a little gas the transmission doesn't respond as if it can't find the gear it's looking for and I have to only coast watching trucks pass me up as hitting the gas will not put the car into a drivable gear. Eventually the tranny kicks back in and 5 minutes later everything is back to normal. Going UP a mountain is never a problem.

Car is in "D." Tranny fluid seems a little thin but seems ok and not hot coming off of the dipstick. I change 2 quarts of ATF T4 w/ every other oil change.

How concerned should I be? I've made this 5 hr trip before many times
and this is a first. I now don't feel safe making this drive anymore and will rent a car to make road trips now.

I appreciate any input

 

That happens at times when the transmission is actually still cold. Engine at normal operating temperature dorsnt mean the transmission is the same. If you havent changed out the transmission, you should do it.

 

've made this 5 hr trip before many times

He was driving for a awhile it seems like so the tranny should be warm...
My guess is if you were going down a steep hill you must have just came UP
a steep hill...
Id say Transmission got too hot and is probably messed up.
if you want to make your transmission last a little longer before changing it out
But when u say "When I go to give it a little gas"
did you try to give it more gas and see if it would kick it because if you are going down a steep hill you may not notice it but it may be in gear
also was the RPM just freely reving or was it way low like 900 or 1000 or was it at like 2000 rpm
if it was at 2000 rpm without u pressing on the accelerator that means u were in gear

 

^^^^This hurt my brain to look at. Complete sentences, people!

 

Yes RPMs were at 2000 but when i step on the gas there was no response...
I spoke w/ a Lexus Master Technician today who said that my problem is that the sharp decline of the mountain rushed all of the trans fluid to one side of the car and that's why I was having problems only in that situation. An answer like that actually makes sense to me and that's the best he can do w/o looking at the car.

His diagnosis was that I didn't have enough fluid. However, according to the dipstick I am at full. So for now I may just keep the car locally and avoid long mountainous road trips for awhile.

Does the master technician's answer sound possible?

 

but how much were u stepping on the gas... because pressing on the gas a little bit on a downhill is not going to do anything. If you stepped like really on the gas and the car took off like if you were going 60 and step on it and accelerated to 80 thats something
im sure that if you just let the car roll it picks up by itself.
just to be on the safe side why dont you get a full transfer of fluid
and did you check the dipstick while it was hot ?

 

I stepped on the gas a little bit and the transmission stalled. I was too scared to give it a lot of gas..

 

WELCOME NEVADAKID

 

Well when I checked the condition of the fluid via dipstick it seemed ok but on a closer inspection I may have solved my own question by saying my Trans Fluid needs replacing. Please visit the following page.

http://www.handogg.com/atf.jpg

The first glass is fresh ATF fluid w/ a cranberry juice type color. The second is ATF as it came out of the car. It had more of a grape juice color. At the same time fresh motor oil looks much different than motor oil that's been used even just a couple of times. From what I remember fresh motor oil is a honey color but after just a little bit of use it turns black right away.

Can someone confirm that the condition of the ATF is so bad that it is likely causing the problem or could it be something else? I feel like I should be worrying because this is a new situation that has never happened before.

Thanks much..

 

Motor oil does get dirty fairly quickly, but if you've ever changed oil after about 500 miles, it's still relatively 'clean' looking -- certainly nothing like new oil, but it doesn't look like chocolate syrup, either.

From what I've seen of ATF over the years, the fluid on the right looks bad. I've got 12k on both my Acura and Suburban ATF fluid right now, and neither of them look THAT dark on the dipstick. I would definitely say an ATF change is in order.