Q: I have what you might call a classic vintage car, a 1988 Lincoln Town Car. When I was returning from the store about a month ago, I heard a loud screech from the engine. I turned the key off, but it kept screeching. About a quarter-mile later, the noise stopped. I had it towed to a shop where they replaced the starter and solenoid and everything was fine for about two weeks, but the problem came back. I opened the hood and smacked the solenoid with the handle of a screwdriver and the noise quit. Do you think the repair shop left the old solenoid in the car?
J.G., Chicago
A: If the solenoid looks old and cruddy, yeah, they probably didn't change it. However, even a new component can be faulty. Give the shop a chance to make it good.
Q: We have a 1980 Lincoln Mark VI. Everything checked out fine during a recent tuneup except that it blows black smoke. The mechanic can't find the problem. Any ideas?
E.L., Allentown, Pa.
A: We don't often have an opportunity to answer questions about classic cars, but two in a row and both Lincolns? Wow. If memory serves us, the engine in that car had a variable venturi carburetor. That's right, an old fashioned carburetor. It needs attention. Black smoke indicates excessive fuel being incompletely burned. By the way, blue smoke comes from oil, not gas.
Q: How do you clean an engine compartment?
B.R., Yorktown, Va.