Today my car started doing these weird things. It first started sputtering from the muffler and blowing out black smoke. I put a quart of oil in it at 1: 30 pm and had to do the same thing again at 9pm. It is a 1992 honda civic with 190,000 miles. Tonight it started back up with the sputtering but also almost overheated on me. My radiater was bubbling like crazy but has no leak or hole. What is my problem and how much do you think it will cost to get it fixed? I was told that oil could be backling up into my cadilienc converter(however you spell it).
Pull out a couple of plugs and look at them. If they are oilly on the tips, not the sides but in the area of the electrode you may have a broken oil ring or something that is causing the oil to get into the cylinders. The overheating is most likely related. Is the level of the coolant dropping as well. My observation would be that if there is oilly deposits on the plugs and you could perform a compression check, but I would opt for a new engine.