Car Doctor: Avoiding a dead battery when not using your car

By John Paul

Q. Can you tell us the action to take to avoid a dead battery when going away for two months? We are in a garage without an electrical outlet. Should we disconnect the battery, and if so, how?

A. If your car is near a window, you could try a solar charger, and with enough sun the battery will stay charged. There are a variety of solar chargers – basic, that can be purchased for less than $30 – to more sophisticated systems offered from CTEK, that manufactures quality battery chargers and maintainers. Yes, disconnecting the negative cable will keep the battery in a relatively good state of charge, but be aware that all the electronics such as the clock, radio presets, and memory functions will need to be reset. Depending on the car, and the condition of the battery, the car may, in fact, start up after sitting for two months, especially this time of year.

Q. I have a simple question that seems to get different answers: how often should the tires on my car be rotated?

A. Generally, twice per year is a good number, unless you drive aggressively, then maybe a little more often. If you check your car’s tires all the time for pressure and wear, then maybe you could even go for a year or more. But like most of us, every 7,500 miles or twice a year is usually good. Rotating the tires periodically is also a good excuse to inspect the brakes, steering, and suspension parts for wear.

Q. I brought my 2006 BMW 535 to the mechanic for a valve cover gasket. After the repair, the check engine light stayed on. What should I do?

A. If the engine light was not on prior to the valve cover gasket replacement, then they most likely left a vent hose off. A visual inspection should be able to find it. Also, a quick check with a scan tool will retrieve a code and help you determine the source of the light.

Q. My car, a 2015 Mitsubishi Outlander, flashed an engine light that said the car engine is too hot. I pulled over then had a hard time starting it back up. I finally drove for about ten minutes, and it happened again. It is now parked. What should I do?

A. If the engine is getting hot the problem could be low coolant, a malfunctioning cooling fan, a sticking thermostat, or even a broken drive belt. I am concerned about it starting hard – this could indicate the engine got hot enough to do some major damage. At this point it would be best to have the car towed to a shop and have it inspected for the cause of the overheating and possible engine damage.

Q. My 2019 vehicle had a recall on the fuel pump. The dealer replaced the fuel pump free of charge in June 2021. The fuel pump failed in June 2023. Does the car maker have any responsibility for a second fix?

A. Generally, no, unless that second part was recalled. The recalled part is warrantied for the extent of the factory warranty period. Depending on the car it could be 3 years 36,000 miles, 5/60,000 miles and this would be whichever comes first.

Q. I recently changed the battery on my 2015 Volkswagen Jetta and when I started the car up, there were multiple warning lights that came on. I made an appointment with the local VW shop and on my way there the lights went out. What happened, and is the car okay?

A. This is typical with this model. The steering angle sensor will come on, as well as the traction control and tire pressure warning system lights. Driving for just a minute or two resets all the lights, and the car is fine.

John Paul is AAA Northeast’s Car Doctor. He has over 40 years of experience in the automotive business and is an ASE-certified master technician. E-mail your Car Doctor question to [email protected]. Listen to the Car Doctor podcast at johnfpaul.podbean.com.

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