Q In 1983 or 1984, my father purchased a Ford Escort with an optional 2-liter diesel engine. He would brag about its fuel mileage, and I was dubious. When my father passed away in 1987, I inherited the vehicle and was amazed to discover that I always got 48 miles per gallon, and occasionally 50 mpg. The car became irreparable a few days before News Years 1998, and I had to junk it. With the very public push for ever increasing fuel mileage and the improved blend of diesel fuel now available, where are the diesels?
H.D., Warrenville, Ill.
A Ford offered the 4-cylinder diesel (built by Mazda) in the 1984-85 Escort, but it did not sell well. There may be diesels on the horizon, but probably not in great number. Although more popular than gasoline engines in Europe, Americans have never warmed up to diesel cars. Maybe it was the noise, the smell, the sooty exhaust or the inconvenience of finding a station with diesel fuel. A very bad experience with GM diesels in the 1980s did not help. Modern diesels are quieter, faster (thanks to turbos), cleaner and the fuel is more ubiquitous. We like the bottom end torque a diesel engine delivers. Diesel cars were always more expensive — something that was offset by fuel economy and durability — and will continue to be expensive due to complicated emission controls.
Q Recently my vehicle has developed a sound, at idle only, like low octane gas ping during acceleration. The vehicle runs fine, gas consumption hasn’t changed, starts easy, doesn’t diesel when shut off. The vehicle is well-maintained. Driving is a balanced mix of suburbs, and long highway trips of at least one hour. Is it a sensor, computer, or timing problem?
G.M., Batavia, Ill.
A It is probably none of the above. It sounds like your engine may be suffering from preignition. This happens when the air-fuel mixture begins to burn before the spark plug fires. Then, when the plug fires, there is a second flame front. When the two collide inside the combustion chamber it causes that characteristic noise. There may be a buildup of carbon in there that can glow and ignite the fuel prematurely.
Q I recently took my 2007 Honda CRV to a local dealer to check out what I believed to be a squeal coming from my power steering. I usually heard it after driving on the interstate at speeds in excess of 70 mph upon exiting. After sitting overnight, the squeal was gone and usually did not appear again until the car had been driven for 20 minutes or more. The dealer told me the power steering rack was leaking internally and needed to be replaced. The estimated charge was $1,600.
I took the car to my regular mechanic shop with the same story. He said he had never heard of a power steering rack leaking internally. He checked the car out and found that the reservoir for the power steering fluid screen was clogged with small particles. He flushed the system, cleaned the screen, and put in new fluid. The squeal was gone. Please give me your thoughts.
J.P., Pompano Beach, Fla.
A We think you should always take your car to your regular mechanic. He sounds conscientious and trustworthy, and he does right to earn your repeat business. Power steering racks can develop internal leaks, but they usually cause hard steering, not noise. By the way, if you are not the first owner who may have gotten a recall notice, ask your mechanic to look it up. The pumps on some CRVs were wearing out internally which could lead to failure and hard steering.
Q Over time I have collected four different brands of partially empty quart containers of 10W-30 oil. I’ve been told that in theory all motor oils with the same API rating on the container should be compatible, but in practice it is not a good idea to mix oils. Ideally, one should find a brand they like and stick with it. This one time, would it be safe to use up all that oil with my next oil change?
A.F., Avon, Conn.
A You may certainly mix brands or motor oil if they have the proper SAE viscosity ratings and API service rating for your car’s engine. If the oil has been stored properly and is clean and moisture-free you may use it. However, to be on the safe side, we would not pour previously opened bottles of oil in our cars. Use that old oil on door hinges, the lawn mower, or whatever squeaks.
Q Since buying my 2007 Buick La Crosse, I have driven only about 20,000 miles, with most of that mileage being from a few long trips on the Interstates. When I took the car into the dealer recently for a routine oil, it was recommended that the fuel injectors be changed. I am wondering if changing the fuel injectors is really recommended, or was it just a way of picking my pocket for $250. I have owned other cars with fuel injectors and have never been told they should be periodically changed even though the car was running fine. Do you believe that this charge was legitimate?
J.R., Mundelein, Ill.
A Replacing fuel injectors is not routine maintenance. Neither is injector cleaning, which we think they sold you since each injector costs over $100. Check your owner’s manual and you will find no reference to injector cleaning. We doubt that it was necessary, but we have not seen your car and it very well may have needed the service to restore its efficiency so we can’t say whether your pocket has been picked, but it probably was.
Q I have a question about the frequency of changing motor oil on a new car. We bought a Kia Forte EX in late March 2010. The car has 5,800 miles on her. When we had an American car or truck, we always changed the oil every 3,000-3,500 miles. The Kia manual says the oil should be changed every 7,500 miles under normal driving conditions. The dealership says every 5,000 miles, and my local mechanic says every 3,000 miles.
Which one is correct?
C.H., Chicago
A The fast lube shops continue to tout 3-month/3,000-mile oil changes, not because it is in your best interest, but theirs. Although there is no harm in changing the oil sooner than recommended, you can follow the maintenance schedule in the owner’s manual. It is more or less an economic decision for you to make.
Bob Weber is an ASE-certified master automobile technician. Send questions to Motormouth, Rides, Chicago Tribune, 435 N. Michigan Ave., 5th Floor, Chicago IL 60611, or e-mail motormouth.trib@verizon.net.
