94GS300

Alright, I have seen quite a few posts for a number of different cars in here that seem to have the same problem I have, or at least I think they do. I have a 94 GS300. The problem is when the car is first started when it is cold outside (below 30F). I let the engine warm up for about 20-30 seconds and then put it into Drive and drive very slowly to take it easy on it. Basically I have the throttle at maybe 5-10% at the most and it will shift to 2nd and everything is fine. When I get to the first street where some slight acceleration is needed, the engine rpm's climb sky high in 1st gear, but the car barely moves. It does this for about 5-10 seconds before it shifts to 2nd and then the problem never comes back. This is so bad that it is very dangerous because people almost rear-end you.

In order for the rpm's to climb and the vehicle not go as fast as it should in 1st gear (correct speed ratio), one of two things must be happening:

1) The transmission is slipping one of the clutches
2) The torque converter does not have enough fluid in it

A lot of people are claiming that the computer is doing this to warm up the fluid faster, but I find that hard to believe. I need to get a schematic of the transmission controls, but the only way the transmission controller would be able to change the speed ratio (output speed/input speed) would be to back off line pressure which would make a clutch slip or cut off fluid to the torque converter. The controller would do neither of these things because it would not reduce line pressure and risk slipping a clutch in 1st gear and it would not cut off fluid to the torque converter because the torque converter is what causes the transmission fluid to warm up.

Any Lexus technicians or anyone else have a good explanation for what is happening? I personally think I am slipping a clutch when the fluid is very cold because either a valve is not opening all the way, a solenoid is not producing enough pressure, or I some debris in an orifice (not likely since the fluid pressure would blow it out). If this was the case though, then all these other people complaining about this would have slipping clutches and we would here more about these incidents.

I have done all the obvious things: fluid level is correct with fairly new fluid and I cleaned the metal filter screen.

Anyone want to take a stab at this?

cyclemax

My car is a 98GS4 with only 20K.

One spring day last year I went to take my car out of the garage (I only use it occasionally) and was surprised to find the battery stone dead (the indicator lights didn't even work). Turns out I left the trunk slightly open and the light drained the batt over the course of 2 weeks or whatever. No big deal. I put the charger on it for a few minutes and fired it up.

I backed out of the driveway just fine, but when I put it in D, it just freewheeled. I'd say it revved up to at least 2K and just barely crept forward. I tried manual mode, shifting to 1, back to reverse, everything. I got out of the car (nausea had set in) and tried to calmly think about things. So I figured it must have something to do with the electrical system being down, and decided to take it for a short drive, albeit very easy.

About 200' up the road the car gently "lunged" forward and the revs came down to normal. I was still concerned, but dismissed it as an electrical glitch, and made a note to myself to get a new battery.

About a month ago, I took my car out of the garage on a fairly cold evening (about 30 deg F). It had not been used in about 2 weeks and the battery sounded like it was laboring a little when I started it. Backed out of the driveway, put it in D and again, the tranny was slipping. Cleared up before I got to the end of the street though. Ran fine the rest of the night.

Some notes:

The first time was a warm afternoon. Probably 60 degrees F.

Both times the car had been sitting for quite a while (2+ weeks)

The problem clears up b4 it shift to 2nd, both times.

This is not the usual "hold 1st gear when cold" GS characteristic. I get that too.

My battery still needs to be replaced.


Even though I'm not using the car for the winter, I probably should replace the battery and see if it happens again. I'd be interested to know more about the control system if anyone knows.

BTW, how comprehensive are the service manuals on CD I see on Ebay?

94GS300

cyclemax,

You have described exactly what I am talking about. I also only use my car every couple of days. But it has been doing it every morning this past week. It just so happens that I had to replace my battery this morning, and the answer to your question is no, it did not have any effect on the problem.

Your description is to a tee of what mine does also. It always clears up before the shift to 2nd.

I really hope it is torque converter related because if it really is a clutch slipping, then I can't imagine it taking too much of this before it gets toasted.

It would be interesting to see if others are having this problem also. It seems like a lot of peole complain of the delay in shifting on cold days, but they don't distinguish between whether it is just increasing the shift point or actually "slipping".

I think I might break down and buy the manuals. I know they are expensive but they are probably worth it. I haven't heard the greatest things about the manuals on CD from ebay. If you get any more info about this situation, let me know. I will be looking into this much further.

cyclemax

94GS300:

Tell me more about what happened this morning. Did you try to start it and it wouldn't, causing you to replace the battery? Then, when you started it, it slipped?

If so, I'm wondering if the problem arises when there is a certain drop in voltage. In other words, could it be that once the voltage drops to a certain level, could you have the problem until the car re-sets itself? So, even though you put the new battery in, the "glitch" may have already been in place, causing you to think it had no effect. Assuming you drove it enough to clear the prob today, I'll be interested in seeing what happens tomorrow.

This is all speculation on my part, BTW. It just seems funny that we both have battery issues as well.

I don't think this problem is what others refer to as the delayed shifting. You wouldn't confuse this.

On the manuals....I thought the CD manuals were just copies of the factory manuals (dare I say bootlegs?). NE1 know for sure?

94GS300

Basically, I could tell that my car was starting to crank slower and slower over the past couple of weeks so today I finally broke down and bought a battery. However, the controllers would have never reset because I hooked up another battery in parallel so that I would not lose power when changing batteries. I did this so that my radio would not get locked out if it lost power because I don't have the anti-theft code from the previous owner. It worked, my radio didn't lock me out so the car never lost any voltage. After I put the new battery in, I started the car up and let it warm up for a few seconds and put it into drive. I drove it and then the problem happened. I have owned the car for two years now and I noticed this last year also, but it was not as bad. It has gotten so bad that I have to wait for the busy roads to be totally clear before I first start out or else I will be smacked from behind.

I will see what happens tomorrow morning when I go to work.

Also, I just got some techincal service bulletin information off of alldata.com. It listed a tsb in november of '94 for a secondary regulator valve modification to the transmission. I will try and look into this further.

blue wax

must always keep the oillevels up top....... if not =
could easely be clutchslipping as a result of burned discs- to less oil
don't forget if you haven't used the car for a while, it takes a few seconds for the pump to fill up tranny and build up pressure.

my 2 p.

yezzzzzzzzzzzzzzzzzz