I bought this jetta a few weeks ago, engine runs great, i knew it had some kind of transmission problem but am very handy with cars so i wasn't worried. after starting it up i noticed the coolant level warning light starts blinking and the engine check light was on and it was over heating, i checked the coolant reservoir and found brown muddy substance inside, i then opened the radiator drain at the bottom and put a water hose in the reservoir and ran the engine, a whole lot of that brown muddy stuff came out. after a about 10 minutes the water was clear and the engine was cool. I then check to see if the transmission was contaminated and when i pull the fluid pan bung instead of transmission fluid coming out it was the same brown muddy substance. so now am sure of two things, 1 my tranny is busted and the fluid cooler is also busted. my question is will i be able to fix the tranny my self or should i replace it?