I've got a 2000 Rodeo 3.2L auto with around 120K, and I'm having tranny problems. I don't have any check trans light on (and it has never came on before), but when the car is cold, I'm having problems with the tranny slipping when I first start off. Once the car warms up, the problem goes away. The tranny also takes awile to shift into 4th gear when the car is cold. I recently changed the tranny fluid and filter because I was having problems will the tranny taking longer then it should to switch from park to drive, but I never had a problem with the tranny slipping until I changed the fluid. I check the fluid level every 2 to 3 weeks and it usually will take about a pint of fluid (sometimes up to a half a quart), but I cant see where its leaking any (even when I jack up the back end and step on the gas with the car in drive). I've added conditioner with stop leak, but this only fixes the problem for 2 to 3 weeks. Other then that, when the car warms up, the tranny does not slip, and the tranny shifts fine.

Has anyone else had this problem? Any what did you do to fix it?

I don't want to waste money replacing the tranny if it doesn't need it.

Ive got the same problem, some people say to clean out your range mode sensor that is attached to the outside of the tranny. But I did this and it did not work, another person stated to me, that he had switch out the whole device.

Ehh, it still works with letting it warm it... so tomato, tomato :-p

I can tell you this, I switched out a whole tranny with a used one, and about 1 year later, it started to happen again (13K later). The first time I took it to a shop and they said the tranny was slipping becuase of leaking pressure causeing the computer to go into a "safe mode". Obviously thats bullshit if I can just warm the damn thing up.

*grumbles*

*slipping* doesn't usually involve the range mode sensor; a hard shift from 2-3rd gear and vice versa are symptoms of the range mode sensor, or rough shifting in general.

But slipping doesn't usually involve that sensor.

What's the history on this transmission, how often was the fluid being changed before all this started?

When you mention slipping while cold, kind of sounds like you might be a bit low on fluid, but how cold are we talking here??

If it's below 20F, you should give your tranny a good 30 seconds or so after you put it in gear before you actually start rolling the truck - allow the torque convertor to refill with fluid, if it's been sitting for several hours.

Another idea, what's your voltage gauge read? If your alternator is failing or old, this could cause the transmission to act up by not providing enough volts - however, you say it's fine once the truck warms up. So, the alt may have nothing to do with it.

Ya know, I was thinking about your truck today - don't know why I was thinking about YOURS :rofl: but, if you're losing THAT much ATF and can't find a single leak or any residue on the undercarriage, I have to wonder if it isn't leaking internally inside the Radiator.

Our transmissions have a tiny cooler in the bottom of the radiator, which, if old & rotted out enough, they can leak internally; i.e. ATF leaking into the radiator & antifreeze leaking into the transmission, which would greatly cause slippage and dramatic damage.

But, you would also see foaming of the ATF and probably would spill out the overflow.

Another thought is, are you *sure* you're checking the ATF level at the correct temperature; as you know, these trannies are not easy to check the level on. But I do know, that the truck must have idled at least 3-4 minutes from a cold start before you pull the fill plug and the truck MUST be running.

Fluid Needs To Be Checked And Filled With Engine Running Trans Iin Neutral
If Not Done This Way Fluid Level Will Be Low And You Will Damage Your Tranny

I have a 2001 Rodeo V-6 4x4 with the auto tranny. I decided to finally (after reading all kinds of doom and gloom scenarios on here) change the fluid and filter at 60k at the dealer. Of course soon afterwards, it started slipping once in a while when hitting the accelerator hard from a dead stop. Over the last few weeks (I have 74k miles now) it has started to have problems every so often when shifting between 2nd and 3rd and 3rd and 4th gears. It will sometimes just rev the engine as if I'm in neutral with the rpm's going up and no shift, until I ease off the gas.
I brought it to the dealer yesterday. He gave me some bs story about having a leak in the pan gasket seal (I am a nut about checking my driveway for spots, and have not seen any since I bought the vehicle) So, they changed the pan and put in a new gasket under warranty. Great, so I thought. On the drive home, the same thing was happening with the delayed shifting and it also slipped twice when taking off from a red light.
I brought it back today, so the dealer could check the fluid. They said it was fine and that it meant it was an internal problem. The service manager said he would talk to Isuzu. He said what they usually do in these cases is ship a new (hopefully not a rebuilt) tranny to them and they will put it in, all under warranty of course. I am skeptical of this. I know there are lots of computer sensor issues with this vehicle. Of course these problems arose after I decided to change the fluid and filter at 60k!
I hope when they give me a new tranny, the situation will be fixed, but I don't have much faith. They said it's usually a 2-day fix.

Jason in NYC

I'd take a new tranny!

Have you actually been under the truck with a flashlight to search for leaks? That much fluid is going somewhere.

I have a 2001 Rodeo V-6 4x4 with the auto tranny. I decided to finally (after reading all kinds of doom and gloom scenarios on here) change the fluid and filter at 60k at the dealer. Of course soon afterwards, it started slipping once in a while when hitting the accelerator hard from a dead stop. Over the last few weeks (I have 74k miles now) it has started to have problems every so often when shifting between 2nd and 3rd and 3rd and 4th gears. It will sometimes just rev the engine as if I'm in neutral with the rpm's going up and no shift, until I ease off the gas.
I brought it to the dealer yesterday. He gave me some bs story about having a leak in the pan gasket seal (I am a nut about checking my driveway for spots, and have not seen any since I bought the vehicle) So, they changed the pan and put in a new gasket under warranty. Great, so I thought. On the drive home, the same thing was happening with the delayed shifting and it also slipped twice when taking off from a red light.
I brought it back today, so the dealer could check the fluid. They said it was fine and that it meant it was an internal problem. The service manager said he would talk to Isuzu. He said what they usually do in these cases is ship a new (hopefully not a rebuilt) tranny to them and they will put it in, all under warranty of course. I am skeptical of this. I know there are lots of computer sensor issues with this vehicle. Of course these problems arose after I decided to change the fluid and filter at 60k!
I hope when they give me a new tranny, the situation will be fixed, but I don't have much faith. They said it's usually a 2-day fix.

Jason in NYC


I'm willing to bet that it won't fix your problem. Part of you problem seems like it's slippage. A lot of people have had their tranny replaced, but the same problems seem to come back.

If it for sure was going to be a brand-new transmission replacement, I don't see how the issue could return in 2-3 days, unless the issue had nothing to do with the transmission in general.

A rebuilt transmission having issues within a few days, or weeks, is VERY likely on the GM 4L30-E transmission - these particular trannies don't seem to do too good after a rebuild.

unless the issue had nothing to do with the transmission in general.


I'm sure it happens. Before I had mine rebuilt I read plenty of posts about people getting a rebuild/reman and having the EXACT same problems as before. That leads me to believe it had nothing to do with the tranny if it was well maintainted. Unfortunately, people come seeking help when it's too late.


BTW, the rebuild I did in September 06 is holding up. Don't jinx me:eek:

it could also be due to a weak alt or battery or ground point.

or the range sensor needs to be cleaned.

....I've added conditioner with stop leak, but this only fixes the problem for 2 to 3 weeks. ....

as i understand it, the 'stop leak' in the atf conditioners is not like that for radiators, but a conditioner for the seals that is supposed to stop the leaks there. so if in fact that is working for you, i'd think there is an external leak there somewhere. maybe the next step is to get one of those leak detector test kits that use a special dye and blacklight to spot the leak source would be a good investment for you....

//bc

Fluid Needs To Be Checked And Filled With Engine Running Trans Iin Neutral
If Not Done This Way Fluid Level Will Be Low And You Will Damage Your Tranny

Thanks for the info. I was told to let the tranny warm up and then fill it, but no ne told me to leave the car running while filling it. I tried that yesterday and it took a quart and a half. I drove it this morning and it didn't slip, put I still have a problem with it taking a wile to get into 4th when it is cold.

*slipping* doesn't usually involve the range mode sensor; a hard shift from 2-3rd gear and vice versa are symptoms of the range mode sensor, or rough shifting in general.

But slipping doesn't usually involve that sensor.

What's the history on this transmission, how often was the fluid being changed before all this started?

When you mention slipping while cold, kind of sounds like you might be a bit low on fluid, but how cold are we talking here??

If it's below 20F, you should give your tranny a good 30 seconds or so after you put it in gear before you actually start rolling the truck - allow the torque convertor to refill with fluid, if it's been sitting for several hours.

Another idea, what's your voltage gauge read? If your alternator is failing or old, this could cause the transmission to act up by not providing enough volts - however, you say it's fine once the truck warms up. So, the alt may have nothing to do with it.


The fluid and filter was changed right before I bought it at around 50k. I read that you should change it at every 50k miles, so I changed it my self at 100k. I started having these problems at around 110k, and I added tranny fluid to it and it took just under a quart of fluid. Now that I have 120k on it, I'm still having problems. I drive around 500 miles per week with my job, and I check the level every other weekend.

I was told that you have to warm the tranny up before you fill it, but I didn't know that you should have it running in neutral wile filling it (until you guys told me). I filled it yesterday while running, and it took around a quart and a half. It hasn't slipped yet, but I'm still having a problem with it switching into 4th when the engine is cold.

I don't think it's leaking fluid, I just never filled it to the proper level to begin with. I just hope the tranny hasn't started to burn up.

Generally if these tranny's are ever allowed to run low, they burn up quickly; you *may* have gotten lucky.

But, I would NOT, I repeat, I would NOT only change the fluid every 50k on this transmission. These GM tranny's prefer good, clean fluid, do it at *least* every 30k if you're doing a full transmission flush.

If you're doing a partial fluid drop, do it at least every 15-20k.

I guarantee you, if you go another 50k without at least a partial fluid swap or two, your tranny will not make it to 150k.

What I would do at this point, because you were still a full quart low - which is a LOT for this transmission to be low on - within the next 2 weeks, get yourself a full transmission flush performed because you now have fluid in there that's partially burnt and won't last long.

FWIW - the computer in these trucks will NOT allow the transmssion to shift to 4th until the engine is at full operating temperature; that part sounds normal to me. Then again, I've never gone above 3rd gear until my temperature is well into the normal operating temp range.

If you're living in an area that requires you to be in 4th gear or above 40mph within the first 10 minutes of the truck running on a *cold* morning, it's probably best if you let the truck idle for at least 3-5 minutes before taking off from your drive way, thus when you need to get into 4th, the engine should then be at normal temperature.