Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 01

by Bob Hagin

Q. I have a 1995 Lincoln Mark VIII with 2776 miles on it which we purchased in June of 1998. We are in our seventies and don't drive it very much. We had the car serviced at approximately 2000 miles because it sits a lot and we know that it is an injustice to it if we don't drive it. We have had a odor problem since we purchased it. When we start the car up in the morning and drive it, we smell exhaust fumes inside. It lasts for about a half a mile and then it goes away. The dealer's shop where we've taken it has been very responsive and gave it all the tests that they know how to perform. They even went so far as to check for factory information through their computer and went into the Lincoln factory bulletins to see if it was leaking in through the air conditioning system or the heater. Could my Lincoln have a leaking manifold gasket or something that would leak when it was cold and then close up as the engine warmed up? S.C. Benicia, CA

A. Although I haven't experienced it myself, I've heard of exhaust gas leaks that seal themselves up as the engine gets hot, but it's usually a crack in a manifold or something metallic. An exhaust gas leak in a gasket just gets worse as the material blows out. Also, a mechanic would hear an exhaust leak providing he or she tested the car under the same conditions as when you drive it. I'd be more suspicious of a fault in the fuel evaporation recovery system. Late model Ford products have been known the have a faulty one-way valve in the fuel return line into the tank. Apparently the fuel backs up and spills into the atmosphere. Try another dealer's shop since your car is still covered by the federally- mandated 5-year/50,000 mile emissions control system guarantee.

Q. My 1975 Plymouth Scamp has a Slant-Six engine. The number one and number six spark plugs keep fouling. We've installed a new carburetor, installed platinum-tipped spark plugs and new plug wires. We have checked the distributor and valves and they are both OK. The exhaust gas recirculation valve has been disconnected. When the engine is cold, it chatters real bad and the engine backfires. It also wants to die when it's cold but after it gets hot, it runs OK. It also runs on when I shut it off. J.J. Springfield, OR

A. The fact that your Plymouth is rough when it's cold and "diesels" when you shut it down points to it running lean. Reattach the EGR valve, made sure it's operating as it should and see if the engine runs right. The lack of exhaust gas in a system designed for it can sometimes make an engine run lean. It's also possible that your choke system isn't operating correctly or that the intake manifold is loose and leaking at cylinders one and six. If your Slant-Six is high-mileage, it's also possible that the cam timing chain has stretched and is retarding the valve timing. Also make sure that its idle speed isn't too high.

Q. I've been told by a car enthusiast that in the past, there have been automobiles that are powered by motorcycle engines. One he named was a Morgan. Are there still cars that have motorcycle engine? S.K. Newport News, VA

A. Morgans with motorcycle engines approach the realm of ancient history. The pre-World War II British used JAP, MAG, Anzani, Matchless and Blackburne engines. They were, in reality, three-wheelers (two in front/one in back) which made them cheap to make and licensable as motorcycles. The problem with using motorcycle engines in cars today are too numerous to list (too small, too tough to keep "clean" for 50,000 miles, etc.) but in the early days of the auto industry in this country, several hundred "cyclecars" built on the same premise came and went. The only four-wheel cars that I know of that use motorcycle engines are go-karts, "Legend" racers and some SCCA amateur classes.