My 1987 190E lost power with smoke noticable behind the vehicle. My wife was driving the vehicle at the time, and she cannot verify the color of the smoke. Massive oil loss was also noticed on the ground below the engine. Assuming a head gasket, I proceeded to drain the oil and antifreeze in preparation to remove the head to replace the head gasket. No mixing of these fluids was noticed. Following head removal, the head gasket LOOKS intact. No compression test was done prior to head removal! Before I continue, what are the possible causes for these symptoms, and what repair/diagnosis steps would be indicated? Also, since the engine used a little oil prior to this failure, is a ring job fairly easy at this point of repair?