Good afternoon!

I need advice on an issue I’m having with my 1998 GS300’s transmission. The engine is completely stock, has 94,000 miles, and has been meticulously cared for since I got her with 61,000 miles.

For the past month or so, I’ve noticed that the transmission seems to hold gears too long, thus upshifting later than I normally expect. I’ve only been noticing this at high speeds; for city driving, the car seems to shift normally.

It is most noticeable when I’m merging onto a freeway and accelerating (not even flooring) the car, I’m in 3rd or 4th gear around 60mph, and the tach just keeps climbing to about 4000rpm before the car finally shifts up into the next gear. Sometimes, the tach just keeps rising, and I let go of the throttle just to make the car shift gears. Before, the car would upshift around 3000-3200rpm. The delay in shifting is very noticeable.

Some background:

-I’ve noticed these longer shifts before in the past few months (though they’ve become way more pronounced in the last month), so Luxury Motorworks reset my ECU, but that didn’t seem to solve the problem.

-The engine is warm when this happens; it’s not happening when the car’s still cold.

-About a year ago, Luxury Motorworks replaced one of my shift solenoids because the “Check Engine” light kept coming on and their computer diagnosed that as the issue. Thus, my transmission has had problems in the past.

Any ideas on what’s going on? Has anyone else experienced this problem (I already ran a forum search)? Does it sound like my transmission is going bad?

Thanks in advance!!

Andrew

 

I'm a "process of elimination" kind of guy.....try cleaning your MAF (Mass air sensor) with some MAF cleaner. I have read that a dirty MAF sensor can cause shifting like this. Its worth a try for $5. If not...might get some other suggestions from other members. Hope you dont have any major issues with the tranny.

 

Thanks for the advice! Is cleaning the MAF a simple DIY?

Andrew

 

Yes....just do a search and you will find tons of info

 

Just curious as to what the MAF has to do with the transmission??

Jonny

 

http://www.fordscorpio.co.uk/cleanmaf.htm


It was just a suggestion.....not saying it was a definate cure.

 

I know the theory behind the MAF and the transmission if the MAF is dirty. Basically, the air hitting the two importang areas of the MAF, air temp and air velocity, takes a little longer since the air needs to 'penetrate' the layer of dirt to poke the sensor so to speak. I clean mine often enough (I live in Mexico City and you know the air quality here).

However, I must say that my RPMs also hang on a few of the on ramps here, especially the one right near my apartment building that leads to the toll road. Doesn't matter if I am flooring it or not.

By the time I get to the on ramp, my RX300 is also warmed up.

I don't necessarily see anything wrong.

When was the last time you changed out your tranny fluid, including differential fluids?

In addition, were you resetting your ECU by just pulling the EFI fuse or also pulling the negative batter clamp off for about 30 minutes to 1 hour as there still remains some juice in the capacitors with just pulling the fuse.

 

Thanks Lexmex for your reply. I just checked my records, and the differential and transmission fluids were changed during the 90k service this past January. The ECU was reset last September at 85k--I don't know how the mechs reset it.

I guess I'm more concerned if something is wrong with my car's transmission. It's just that the transmission only recently has started acting this way. However, if that's the way it runs and there's no problem, I can live with that. It's just annoying that the car won't upshift back like it used to.

I'll probably take the car back to LMW to have them take a look at it.

Thanks!!

Andrew

 

did you have the tranny fluid changed,,, or flushed,,,, might need a flush,,,, and a diff service,,, these car almost never never have tranny problems,,, of all the gs,,, i have seen that are driven normally and driven hard,,, none has needed a tranny rebuild.....

 

I have done a flush on my RX300 only because it had silverly/pinkish fluid indicating metal particles in the fluid and the flush was going to wipe that stuff clean unlike a drain and fill.

With the differentials in the future, I would highly suggest switching to a 75W90 synthetic. I used the one from Royal Purple but some have used the Mobil 1 gear oil. However, that may be another 70 to 100K.

Absolutely disgusting what came out of my rear differential (metal particles) and transfer case (obnoxious fluid that cause some of us to nearly vomit).

I would check the color of your tranny fluid just to see what it is.

 

At the 90k service, I had Luxury Motorworks use Royal Purple for the differential fluid.

What color should my transmission fluid be?

 

What should go in there as far as OEM fluid is Toyota-Type IV ATF, which is red in color.