What may cause the transmission fluid dirty in this 2001 Chevy Impala?

Yes, some would disagree, but I would have the transmission flushed as soon as possible and they may have to remove the transmission pan also to change the filter. Brown fluid is not good because it's supposed to be pink, and you normally want to change the fluid while it's still pink. Your transmission may have operated in higher temperature severe service especially if you pulled a heavy load like a trailer. Heat kills transmissions, and you should install a transmission cooler in front of the radiator if your towing anything or driving the mountain ranges etc. The manufacturer's want you to think you can go 100,000 miles without flushing the fluid, but I think they're stretching it especially GM with their "Dexcool" also which many times is being found to gum up well before the 4 or 5 year mark they advertise for flushing the coolant. So while your getting your trans flushed, get your Dexcool changed too!

The first thing you would want to check for is any obvious signs that the transmission isn't working properly, as far as it not shifting when it's suppose to or not shifting at all. Then inspect the fluid to make sure it doesn't smell burnt or look black. Just cause the fluid is a little darker then usual doesn't mean the transmission is bad. What I would recommend is to take the vehicle to a transmission specialist and have him double check it just to be safe. Then, the next time you have your transmission serviced I think it would be a good idea to have who ever is working on it to flush out the transmission lines as well. What you have to remember is that on all automatic vehicles the transmission fluid runs through the radiator so when you service the transmission there's still fluid in the system. When the dirty fluid mixes with the new fluid even after you just serviced it, it tends to look a little darker then usual. Other then that it should be safe to drive just remember to have it checked.

Replace the transmission fluid and filter ASAP. No transmission fluid will last 100,000 miles in good condition, even if it is a synthetic formula in a fancy European car. The fluid should be drained and filled (and/or pumped out and replaced), not flushed. The flushing machine will probably be contaminated with crap from other cars that had black fluid with metallic shavings. Replace the ATF every 25,000 to 30,000 miles. Use an oil/fluid extractor if you don't want to crawl underneath the car. This method is less effective, but is still helpful. A decent fluid extractor costs $40 to $80. They were originally made for boats. The filter outlasts the ATF. But it's time to change it now. If you do a drain and fill (or pump out and fill), do it again within two weeks. You can only replace some of the ATF each time because most of it is in the torque converter. I recommend using Valvoline MaxLife ATF for your car.

Im sorry to tell you, but you got taken for a ride by chevy. Transmission fluid should be replaced every 30,000 or 2 years. Some companies claim you never have to change, or specify amazing intervals, but they only do so because americans are lazy, and a low maintainence car is what we shop for.

Also you should replace your brake fluid every 2 years, power steering fluid every 2 years, fuel filter every 30,000 miles, and water pump every 90,000, right with the timing belt.

Sorry you had to find out the hard way. Change the fluid ASAP, change the filter too, and dont worry, I doubt much if any damage has been done, the transmission will still last you a long time.

There is a new GM fluid Dextron IV,the bulletin recommends a flush and flow,which is different than a simple trans. service.In a trans service they remove the pan replace the filter,and clean and inspect the debris that sticks to the magnet,what ever is stuck to the magnet, came from your trans. if there is a lot of debris,then the trans is wearing out. smell the fluid if it smells burnt like brakes smell when they get hot,then the trans is slipping.The flush and flow,they attach lines to the trans and pump solvent through the trans until clear,and then pump new fluid until filled,about 11 to 12 quarts.

Bobweb and Autotechgenes are both correct dont just change the filter and fluid, have it flushed, i say again FLUSHED, because there is still a lot on old fluid still in the converter. adding new fluid with old fluid still in the converter just makes new fluid as bad as old fluid do this every 40000 miles. it costs more to flush the tranny, but not as mush as replacing the tranny

you need to go ahead and change it now ,sometimes the owners manual is a little off on the mileage,you need to change the fluid and the filter in it,the dark color indicates a lot of mileage ,so it would be a real good idea to do this right away,if it has a burnt smell to it this also indicates a sign of overheating also,as long as its not giving any problems right now it should be ok,but be careful and keep an eye on it for a while,also notice if the shift of it changes in any way,if it does take it to a transmission shop,right away,good luck with it,hope this helps.

No, It perfectly fine and normal wear and tear. Its just changes color when the trans. fluid starts breaking down. I would suggest getting a trans flush and/or filter changed.

Its possible the bucking you are describing could be misfired spark plugs. When was the last time you had a tuneup? Also check your tranny fluid. If it is turned brown and is not red, you need to change it.

yes change the fluid now. you may have burnt the clutch plates by trying to jack rabbit start in traffic have your shop run the fluid threw a filter to see if you have metal shavings in the fluid.