2002 Cavalier Trans/Electrical Issue?

[scooke50]

Have a 2002 Cavalier, 4 door, auto trans. It's been one of the most reliable cars I've ever had, and I've been driving since the early '60s.

But a few months ago it started acting up and I took it to my Chevy dealer and they didn't see anything. One day when the car was very warmed up it started to demonstrate the classic "slipping" signs of a slipping transmission. When it did, the speedometer would swing wildly as would the tach, and it sould seem like the engine is racing. If I take it verrrry slooooow, it might shift okay. Makes people behind me understandably impatient. It gets worse if the trans is under strain, like going up a hill. Going down hill, with some momentum, is usually not a problem, but where I am at in southern California, there are lots of hills, and this car now has a problem climbing hills. If I make it onto the freeway and get up to speed without a lot of starts and stops, or hill climbing, I'm okay. It got so bad last weekend that I had to pull over and call a tow truck to get me home. At that time, the engine would be racing, but the speedometer would not move. It's sitting at home now, and if I go home, it will start up fine, I will drive it to the store with no problem; but after it gets warmed up, the "slipping" will start, especially if I'm going up hill and/or try to "wind out" in each gear.

The car has 133,000 miles on it. I had the transmission serviced/flushed at 100,000 along with a tune up.

I know that this may sound like a transmission problem, but I can't help but feel that this is as much an electrical problem. Am I right? Any help would be appreciated; I need to get this fixed, because I'm sharing my wife's car, and we're about to start fighting.

[Airjer_]

Is the check engine light on?

Can you fell it shift up and down into gears. Can you feel it down shift into first gear when coming to a stop? Does it feel like you are starting in second gear from a stop? Have you tried up/down shifting with the shift lever?

[scooke50]

The Check Engine Light is not on. The engine is fine. Although, the Trac On light has come on a few times.

After coming to a stop the transmission goes back down to first. And I can go through the gears manually. The problem starts once the car is warmed up and at normal operating temperature. Then, it may start slipping in each gear. If I start off cold, and drive short distance locally, I'm alright for a while, but the slipping WILL start.

I was wondering, is there some king of electrical module that controls the transmission? If so, could that be part of the problem?

Thanks for the reply.

[ricebike]

where was this serviced? at the dealer? maybe they used the wrong fluid...

and i read my shares of transmissions going bad after a "flush" job...

[scooke50]

The car was serviced at a dealer. I figured they were less likely to use the wrong fluid than if I had taken it to a generic auto repair place.

Besides, it was more than a year from servicing until it started to act up.

[ricebike]

that sucks, hopefully the internal clutch packs are not worn... if so, rebuild time
the fluid is thicker when cold... as it's heated, maybe its thinning out to the point that it'll slip

sis had a 2.2L version with a trans that has NO dipstick for you to inspect O_o

do you have the 2.4L version with the dipstick? if so, can you pull it and check/ smell the fluid to see if it's clear red or brown and burnt?

i've found some TSBs but not specifics on them... no recalls though

http://repairpal.com/chevrolet-caval...d_tsbs#tsb_821

oh, i found a way to inspect the trans fluid level on those with no dipsticks:

http://www.j-body.org/faq//123/

[scooke50]

I've got the 2.2 with NO dipstick. Checking the fluid level is a hassle.

I think I'm going to have to take it to the local AAMCO. Not something I'm looking forward to.

Thanks for the help.

[ricebike]

i dunno, may have to go dealer since you went there previously... hit or miss on those AAMCO stations, depending on the workers...

you can scan through the j-body forums if it may be an electrical problem; but i dunno...

the fluid check is definitely the easiest way to see if your clutch pack is toast & i agree its such a hassle to raise up and support all 4 corners of the car in a driveway

[scooke50]

I'm not particularly enthusiastic about going to an AAMCO place. But I went to my dealer once already, and they just scratched their heads, which means they aren't especially competent about transmission problems. Since transmissions are their specialty, they ought to be able to tell me for sure if it is the transmission.

Thanks for the advice.

[Blue Bowtie]

If the transmission isn't already damaged to the point of rebuild, it will be if the vehicle continues to be operated this way. Something needs to be done before it's too late - If it isn't too late already.

You mentioned that you can "go through the gears manually" but didn't mention if this helps once the transmission is hot. If so, the oil pressure is inadequate to actuate the clutches. Operating in a manual range bypasses the PWM solenoid and applies full line pressure to the system and can help worn clutch packs hold better.

Perform a pressure test. You can connect a 300 PSI gauge to the port on the trans almost in line with the input shaft. If the oil pressure falls drastically once it warms up there may be several problems. If the oil pressure remains within specs the problem is likely worn clutches and steels and/or apply piston seals blowing by (leaking).

Regardless of the diagnosis, I didn't notice anywhere in your posts that mentions changing the trans oil. If it hasn't been done it would be a good idea. Whatever you do, hear, read, or believe, DO NOT allow anyone to perform a machine "flush" of the transmission. Drain the pan via the plug then remove the pan. Clean everything that is accessible and inspect the magnet. Inspect the oil tubes on the underside of the case (above the pan) for cracks, signs of leakage at the ends, or restrictions. Install a filter and replace the pan. Fill the trans to the correct level through the fill plug (upper level plug). Run the pressure test again to see if new oil has improved pressure and performance.

For the moderate cost of a filter and trans oil you can have a pretty good idea of what is happening in the trans.