Hi guys, im not sure if this forum is very active or not. But I have a 04 Ls Monte, Front wheel. My car will not go over 40 mph in 3. But when in regular Drive, it wont go past 25, but will go 35 with half pedal boost(if that makes sense) I have changed fluid and filter 2 times. The first time I replaced the fluid, it was black and burnt really bad, and lacked 4 quarts. I have not done a flush.

As I have done countless hours of research, I see that it could mean so many different things relating from the Catalytic converter to a shift solenoid.

Anyone have similar problems or any solutions? Any will be neccessary.

 

Codes? How many miles? Maintenance/owner history? Did this happen suddenly? What you describing is likely a bad cat (broken matrix and clogged up). A muffler shop could tell you.

Black and burnt fluid is not good. A "flush" would likely cause more problems. Does it shift normally from first to second (to third) or are you manually going through the gears?

There are many threads here covering just about everything that happens to these cars, do a search.

 

Codes are unknown as mechanic kept hidden. 136,000 miles. 2 previous owners, no maintenance history. Im not sure as we bought it this way. I didnt do a flush for that reason. 1st, 2nd, and 3rd, work fine manually. But in Drive, it wont pass first. Rpms will be fine until they hit 3500 and rev from there. Transmission does not make wierd noises or anything out of the ordinary. And i will do a search.

 

Fwiw, I had a 92 caddy doing the same thing, it was the electric solenoids in the tranny sticking, I tried a snake oil solution (nothing to lose),
the product is called shudder stop as I remember and it loosened up the solenoids, I also went on you tube, and looked up "stuck chevy
transmission solenoids" lots of info. Good luck.

 

You need an honest mechanic. Sounds like the one you used is a little shady. You can get the codes pulled at most any autoparts store (Advance, Auto Zone, O'reilly, etc.). The codes will tell us a lot of what is happening. But the burnt transmission fluid says a lot.

I have had a couple transmission where the fluids was burn black and after changing it a couple times (one after the other), the transmission was drivable again. (Would not count on it to last but at least buy some time). Also had ones that nothing short of a rebuild could help.

As oldredblackie pointed out, you can try some of the snake oil treatments. You have nothing to loose and/or another fluid change to get rid of more of the burnt fluid. If the fluid is as bad as you indicated, I suspect you are going to need a rebuild (or replacement). But, check the codes first. Maybe it is something simpler.