Q: I own a 2017 Nissan Rogue that has 56,000 miles on it. Whenever the temperature gets below 25 degrees, the car won't up-shift out of what seems like fourth gear until the engine warms up. The colder it is, the longer it takes, sometimes up to two miles. Is this normal for this car? The dealer service person said to let the car warm up before driving and that is normal for that transmission. Of all the cars I've owned, I never had to do this. This is not a big problem, but it seems strange. The car sits outside.
A.F., Eagan, Minnesota
A: The engine must reach operating temperature before the catalytic converter can do its job. That point is referred to as closed loop. Until that time, emissions are untreated. Carmakers use every opportunity to get the system in closed loop and maintaining high rpms by delaying the transmission from shifting helps. Short answer? It is normal.
Q: My question: With all the cars that have been made, are being made and that will be made, how the heck do they avoid duplicating VIN numbers?
D.E., Westchester, Illinois
A: Vehicle Identification Numbers (VINs) can tell you quite a bit about your car. The first group of three numbers and letters identify the county of origin. The number 1 is for US, 3 is for Mexico, S is for Germany, for example. The next group of numbers is usually the make name such as Ford. Skipping to the 10th position, letters B through Y indicate the model year from 1981 (the year NHTSA standardized the system) through 2000. Then numbers indicate the model year from 2010 through 2030. There’s a cool chart on Wikipedia you may want to check out. https://en.wikipedia.org/wiki/Vehicle_identification_number
Q: I drive a 2016 Mazda CX-5 with 62,000 miles. I had the wheels rotated and when I drove it home, the first time I used the brakes at a stop sign, the steering wheel began to dramatically shake. It eventually resorted to normal as I drove further. What happened?
B.W., Chicago
A: Check the lug nuts. They should be snug. If they are tightened unevenly, a hub or rotor may be damaged. Gently drive back to the shop for inspection.
Q: My 2012 Dodge Grand Caravan has a unique method of bolting the battery cable to the battery. Can you please explain how to properly fasten the cable to the battery? Even the tech was baffled.
W.U., Tinley Park, Illinois
A: The nut closest to the battery terminal provides the clamping force.
Q: We have been changing the oil of our 2018 Honda CR-V whenever the on-dash indicator tells us. We started to take the car to a local mechanic instead of the dealer. He states the indicator oil change interval is too long and recommends every 5,000 miles. They also recommend flushing and cleaning prior to placing the new oil due to the oil being too dirty. What is your opinion on the oil change interval and the flushing and cleaning?
G.R., Barrington, Illinois
A: Unless an engine has been so neglected that there appears to be tar on the dipstick, I wouldn’t even consider flushing the engine. Modern motor oil is a miracle of chemical technology. It contains all the detergents you need. Follow the carmaker’s schedule.
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