Question: I have a 1982 Honda Accord that misfires only after being parked on a hill facing down or on a slant to the right. A mechanic said Honda suggests cleaning the No. 2 spark plug for this problem. Is this a design defect that causes fouling of the spark plug?--B.R.
Answer: A number of Honda owners have written with similar complaints about problems starting after their car is parked on a hill. It does not, however, seem to cause spark plug fouling, as your mechanic indicated.
When the car is left parked on a hill, it exacerbates the problem of gasoline boiling out of the carburetor and into the intake manifold. This results in flooding or an overly rich condition when the car is started later on.
Many cars have this problem with carburetors, and Honda is certainly no exception. The 1982 Accord can be troubled with fuel boiling out, especially on hot days and when the car is restarted before the engine cools off. Some later Accords were equipped with a system that keeps the electric engine fan running to help minimize the problem. For a time, these systems could be refitted to earlier Accords. You may want to see if your Honda dealer can still do the work.
The misfiring problem can often be tolerated. It almost certainly does not indicate a major problem that would reduce the life of the engine.
Q: I am the owner of a 1963 Volvo 122S. The service manual calls for a non-hypoid SAE 90 oil in the gear box, while the differential takes a hypoid SAE 90 oil. What is the difference between hypoid and non-hypoid oil?J.F.P.
A: The word hypoid refers to the combination of ring and pinion gears in the differential that convert the rotating motion of the drive shaft to the axle. This requires a 90-degree turn in the motion.
The ring and pinion gears needed to do this job have highly contoured spiral and bevel teeth that create extreme pressures in the lubricants bathing the gears. These gears are also called spur gears.
Hypoid gear oils differ from motor oil in that they contain more additives, known as extreme-pressure properties, to properly lubricate spur gears. Typically, these additives are sulfur phosphorus compounds.
A non-hypoid gear oil does not contain as many extreme-pressure additives. But all gear oils contain some of those additives, along with additives to retard oxidation, corrosion and foaming.
Gear oils are graded by the American Petroleum Institute, or API, with a designation on the can or container. The designation GL-5 refers to the hypoid gear oil with the greatest amount of extreme-pressure properties.
The Society of Automotive Engineers, or SAE, has a somewhat confusing system of grading the viscosity or weight of gear oils. Most gear oils carry an SAE 80 or SAE 90 grading. But these gradings are not on the same scale as motor oils, which are typically 10W-40. Curiously, the viscosity of an SAE 80 gear oil is about the same as an SAE 20 motor oil.
Q: The hand brake on my 1985 Toyota Corolla is giving me problems. When I want to disengage the brake, it is difficult to push in the little knob that releases the brake. Is there anything that can be done?--M.H.
A: The hand brake relies on a ratchet system to lock the brake lever in place. If the teeth don't have any lubrication, they can become difficult to operate. You may want to try to lubricate the entire system, using a graphite spray that will reach inside the mechanism.