I have a 76 Eldorado 500 fuel injected. Bought the car a few months ago and haven't driven it since the engine runs rough etc. am just getting into it now. The issue I am looking into now is it seems to be burning oil as there is blue smoke coming from the tailpipe while the engine is running. The car has 78,000 miles on it. I changed the plugs this past weekend but still runs rough it sounds similar to when the catalytic converter is plugged however someone before me removed that. I would really appreciate any insight as to what could cause it to burn oil besides issues with the valves etc. I am wanting to try to do the simple fixes first before I tear into the motor.
Automobile(s): 1977 Coupe (blue), 1977 Coupe (yellow), 1977 Coupe (green)
Re: burning oil
Two reasons an engine burns oil - worn valve guides or problems regarding the rings / cylinders. Without a description of the history of this engine, it is difficult to make a determination as the cause. Too much oil in the crankcase can cause an engine to burn excess. Clogged oil returns can have the same effect. With the 500, excessive oil in the top end usually results in a telltale valve cover leak. If you have the proper tools, you can also do a cylinder compression test, which may give you an idea as to the cause of this.