Q: My check-engine light has been on for months as of this writing. I took my car (1997 Infiniti I30t) to three auto repair shops but no one could diagnose any problem. I was told by the third shop that it's OK and safe to drive with the light on. I am still driving the car and the light's still on. What is your feeling about this? Am I putting myself and the car at risk? What should I do (if anything)?
C.A., Fort Lauderdale, Fla.
A: The check-engine light illuminates whenever there is a malfunction that may result in increased emissions. That leaves a lot of stuff — from spark plugs to temperature sensors to oxygen sensors and more. To help the technician narrow down the search, trouble codes are stored in the onboard computer, which are read using a scan tool. Sometimes a component may be malfunctioning and the driver will never notice a difference in performance. You should get it fixed for two main reasons: First, the vehicle will not pass the emissions inspection; second, if left unfixed it could lead to a larger and more expensive problem. It is unlikely that you are at risk, but your car is.
Q: I recently purchased a brand-new 2017 Honda CR-V Touring model with a 1.5-liter turbo engine. I drive an average 480 miles per week, 25,000 per year or more. I passed down my 2005 Honda Pilot (with 180,000 miles) to my sister. I loved the Pilot and the reliability, longevity and handling of the Honda in general (except those damned Takata air bags!). But I wanted something new and with better gas mileage. I thought the CR-V fit the bill. However, my brother-in-law thinks buying a four-cylinder for high mileage driving is a mistake. While my brother-in-law is by no means a trained mechanic, he is certainly mechanically knowledgeable. Is he wrong? I hope your answer will put me at ease.
T.H., Newtown, Pa.
A: If it were true that four-cylinder engines don't hold up, the shoulders of our highways would be littered with more cars than beer cans. It is becoming nearly impossible to buy a car with a V-8 engine and six-cylinder cars are not very prominent, either. Car companies need to meet corporate average fuel economy standards so smaller engines will continue to prevail. Not to worry.
Q: I used to do my own oil changes, but now go to shops and dealers. I always check the level after an oil change. Recently, it seems the oil is underfilled. I was always told to fill it to the top mark on the dipstick. The cost of a quart of oil is strong enough incentive to underfill the car. I asked a shop and they said they fill based on what their computers say to add. Have you encountered this problem?
A: We have never had this problem because we do our own oil changes. But what you see may not be a plot to rip off customers. If you pull the dipstick as soon as you reach home, you may not get an accurate reading. All of the oil may not have had time to flow back down to the oil pan. Wait at least five minutes if you want an accurate measurement.
Bob Weber is a writer and mechanic who became an ASE-certified Master Automobile Technician in 1976. He maintains this status by seeking certification every five years. Weber's work appears in professional trade magazines and other consumer publications. His writing also appears in automotive trade publications, Consumer Guide and Consumers Digest Send automotive questions along with name and town to motormouth.tribverizon.net.