Q. I have a Toyota Tacoma that has a problem, the battery goes dead, eventually. The shop thought a parasitic drain, but after doing some testing after about 20 minutes any drain is gone. They suggested a new battery and alternator. The battery because this one has died a few times in the last month. The alternator because it did not seem right. I replaced both myself and now eight weeks later, dead battery. Any thoughts on this?
A. It certainly sounds like the shop was headed in the right direction. If this were my car I would look for a voltage drop. Measure the charging voltage at the alternator, then at the battery, those numbers should be almost identical. If not start looking for corrosion at the power and ground wires. A tight but dirty ground connection can limit charging and over time allow the battery to discharge to the point the car will not start.
Q. This may be a silly/dumb question. I watch a lot of YouTube videos on car repair, and I have heard several of the hosts talk about letting the smoke out when testing electronics. What does that mean?
A. That is an old expression. It comes from the idea that all electronics run on smoke and when you let the smoke out the part does not work. Well, the components do not have smoke in them, but if you short out an electrical component, it will overheat and burn/smoke. A functional part that has been tested improperly can short out and fail, because you let the smoke out. By the way, the only dumb question is the one you did not ask.
Q. I took my 2020 Subaru Forester into my Subaru service center for an oil change and ‘free’ battery check. They advised I not only needed a new/improved battery, but that the new/improved battery is larger and requires a larger pan. The cost is $515. They also mentioned that this battery improvement was because of the stop/start feature. (A feature everyone I know hates.) Is this for real? I never received notice about this change in battery and wonder why I am footing the bill for Subaru’s upgrade. The car has 17,800 miles. While I was unable to drive earlier this year, the battery did die due to non-use. I had it jump-started and then checked at AutoZone. It has been fine since then although I only drive every few days, short distances.
A. At five years old the battery is likely at the end of its useful life. There was a technical service bulletin, but no recall on this issue. Also, there was a class action against Subaru but that has passed although there is free battery testing and part of the settlement. At this point if you intend on keeping the car, it makes sense to replace the battery, tray, and hold-down bracket. Now certainly since you have had no problems up to this point you could just replace the battery with the same one that is in the car now and got you five years of mostly trouble-free service.
Q. I have a 2014 Jeep Cherokee, and a light came on “service emergency brake”. I brought it to the dealer and was told the problem was the module and connector. The cause according to service department was I had water in the trunk. They said they could bring in a person that finds water leaks starting at $400. I refused this and all they did was replace the module and connector for $1763.00 which includes labor. Since I got the Jeep back, I have never had any leaks going through the car wash or with heavy rain downpours. What is your opinion on this? In my opinion this sounds like a scam to bring in a water leak checker.
A. This is a fairly common issue with this module to the point Jeep came out with a technical service bulletin number 08-060-16. In the bulletin it states to replace EPB (electronic parking brake module and connector and look for corrosion at the connectors. The most common leaks are from a body seam where the seam sealer compound failed or if the car has a sunroof a possible clogged drain. A very slight leak over 11 years would only show up as moisture/dampness and not a puddle.
Q. Not really a question but a comment. I have been reading your column for what seems like decades. In some of your answers you encourage readers to do some minor repairs themselves. Recently I was at the Subaru dealer, and they suggested I replace the cabin air filter for $99. I remember you said in many cars it is quite easy to do. I went home did a little research, purchased a high-quality filter, and replaced it myself for $15. Thank you for all the information you have provided over the years.
A. Yes, some repairs can be simple and, in your case, saved you nearly $85. Other repairs can be more complicated but with labor costs in some cases over $250 per hour, a little research and effort can certainly help keep money in your pocket.
Q. I recently purchased my 2021 Subaru Outback when my 42-month lease ended. I currently have just over 23,000 miles. The dealership provides free state inspections for as long as you lease or own the vehicle, and they also inspect all vehicle systems beyond what is required. My gas mileage is exactly what it has been since I first took delivery, namely 23.8 mpg in local driving and 38.5 mpg on 400-mile road trips. The service advisor told me I would need two services; a differential fluid change and a throttle body cleaning because “the car seems to be running rough.” I asked to see a sample of the differential fluid and it did look a little degraded, so I agreed to do that, although I told him that at $180/differential, given the cost of the fluid, I thought it was overpriced. I also asked to see the throttle body which they provided a video of, and it did have a very light amount of deposits on it. I declined that $369 service. Does that sound reasonable?
A. Some Subaru models can have an excessive amount of carbon buildup in the combustion chamber and Subaru has a procedure to clean up the deposits, which also includes cleaning the throttle body. Generally, this is performed if there is a code, indication misfires. Using the fuel additives and Top-Tier fuel should prevent the issue. I would have also passed on this one. As for the differential service, to perform the service properly takes about an hour per differential. There is no set service interval other than if the fluid has degraded it makes sense to replace it.
Do you have a car question? Email the Car Doctor for a personal reply: jpaul@aaanortheast.com.
John Paul is AAA Northeast’s Car Doctor and a nationally recognized expert in automotive technology and repair regularly answering reader questions in columns published across the region. He began his career as an automotive technician and attained ASE master technician certification more than 40 years ago.
Do you have a car question? Email the Car Doctor for a personal reply: jpaul@aaanortheast.com.
