Hello everyone, I need some serious help with my 1980 Mercedes Wagon 300TD. I have multiple problems with the car and I need some help with figuring out what the problems are especially if my car doesn't sell I would love to be driving it around. Problem #1: Overheating - So when I got the car it started overheating and neither hoses going to the radiator were getting hot while the car was running so I replaced the thermostat. It was a success and I was back at it driving the car again. Recently, the car is overheating again and I believe it is the waterpump. I say it is this because the top hose is cold and the bottom hose going to the radiator is hot. It is getting no circulation of the coolant which makes me think it's the water pump. By the way, there is no leaks so I know it isn't a hose. So for the first question is, has anyone else ever have this problem and if so what was it or does anyone know what it may be? Is it the waterpump or is it something else? question #2: this question goes with the first, how do I know my head is good? I know that one way is if the head is no good the oil could be like a milky color and it isn't. It's extremely black. Now, I can't explain it perfectly but on top of the valve cover where the cap is for the oil, when the car runs for about 10 minutes, if you unscrew the cap smoke is pouring out of this hole where the oil can be seen? Is this an indication that my head is warped or bad? Defiantly a problem but I need to know what it is? There is also oil around the valve cover, not to sure if this is related to the problem but the more info I give the better! Lastly question #3; Recently I believe that my parking sensor is gone? My car will not start when in park but if I shift it into nuetral then turn the key it starts right up. So I'm asking if the parking sensor is the cause of this and if not does anyone have any idea? Well thanks guys in advance , hopefully I get some good feedback!