Q. Is there a time limit on how long you can keep anti-freeze? I have an unopened gallon that is a few years old and a half gallon equally older. Thank you and thank you for your great column.
A. The open bottle, if it is more than a year old, I would toss it. The closed bottles are generally good for five years and some can last much longer. Afterall some cars do not have coolant changes for up to ten years and Audi in some models state the coolant is good for life. The bigger issue is coolant formulation changes with new models and the newer formulations are generally backwards compatible but old mixes may not be suitable for newer cars.
Q. Here’s my issue you might have some insight into. When driving my 2022 Mazda CX-5 in stop and go traffic there is a “chug-a-lug” feeling as the transmission downshifts from 3rd or 2nd gear. It feels like it is searching for a gear and not quite fitting into it. The car is just three years old and has 29,000 miles and I do not recall having this on my previous 2014 model. Any thought as to what might cause this or any bulletins from Mazda?
A. There are no specific technical bulletins for this issue. At this point you need to start at the beginning and the very first thing is to determine if this is a normal characteristic or something is wrong. It could be a normal characteristic (not desirable but normal) that with a combination of transmission torque converter operation and cylinder deactivation and car is just not quite sure what gear to be in. Mazda, in service data recommends comparing the vehicle to same year and model to rule out normal characteristics. Also, a professional level scan tool should be used to check for any pending codes. Mazda may even do a basic reset of the transmission computer to let the car relearn your driving habits.
Q. I recently purchased a used 2024 Hyundai Sante Fe, the Calligraphy trim level. The car has only 3000 miles on the odometer, it was a dealer loaner car. The tires are Pirelli Scorpion MS and are obviously in very good shape due to the low mileage. Just for curiosity, I checked the tire price online and was shocked to see the price per tire was about $485, which is double what I would normally expect to pay for an SUV tire. When the time comes to replace these tires, am I locked in to buying such expensive tires or can I replace them with a more conventionally priced tire?
A. Unfortunately, with a 45-aspect ratio and a 21-inch wheel size the tires choices are limited. Looking locally at major brand tires you will be spending $350-$500 per tire. Looking online at Walmart and SimpleTire, I found much cheaper tires made in in China and Korea. I will admit they are names I have never heard of, such as Lionheart and Lexani and both were priced under $150. Are these tires as good as a $450 brand named tire? My guess is no, but I have been surprised by bargain tires before.
Q. I am considering purchasing a new Honda CRV but recall that there have been problems with dead batteries on this car due to parasitic battery drain. I understand that all new cars will experience some parasitic battery drain. However, it seemed that the CRV was experiencing issues resulting in dead batteries if the car was not driven enough. I am retired and do not use my car every day and most of my driving consists of a few miles back and forth from a store. Under these driving conditions, am I likely to experience problems with battery discharge? If so, are there other car models that are not so prone to battery issues.
A. Honda sells about 300,000 CR-Vs in the US every year and although there have been some problems with relays sticking and causing dead batteries the number is very small (in the hundreds). Some CR-Vs had what could be considered undersized batteries with not enough reserve to handle the normal parasitic draw. With most newer vehicles one drive of 20-30 minutes once per week is enough to keep the battery charged. The CR-V is one of the best SUVs of its size and one the I would buy.
Q. My check engine light came on several months ago on my 2007 GMC truck and the scan claimed issues with the Fuel Tank Pressure Sensor. In December there was major body work for rust removal. That included removing the fuel tank. My question: when the mechanics removed and installed back the fuel tank, how likely might it be that the return trip was not up to par, so the check engine light came on. The problem is I cannot prove any degree of negligence, but I do not want to have to perform costly work if it is not necessary.
A. It is possible that the wiring was damaged or just rusty and crusty and fell apart at the tank when the rust repair was performed. The wiring sits above the frame rails and if they did rust repairs, it is certainly possible. The sensor is part that sits in the area of the fuel tank senser and fuel pump. To inspect the wiring and sensor the fuel tank typically needs to come out or at least be lowered. I would first start by talking with the technicians that performed the rust repair and then go from there.
Q. You have said you answer every car question, but this isn’t a true repair question. When getting your car repaired is it better to tell the mechanic everything you know about the car or just let them diagnose it? A friend of mine keeps telling me the more you say, the more it will cost, what do you think?
A. I have to disagree with your friend. If I were fixing a car, I would want to know the history of what work was performed, other possible diagnostics and what DIY repairs were performed.
Do you have a car question? Email the Car Doctor for a personal reply: jpaul@aaanortheast.com.
