Advanced safety systems, Corolla towing capacity, error codes, rumble at 35 mph
Q. I purchased a new Subaru with the advanced safety system (EyeSight) that is designed to help prevent collisions and hopefully keep me and my family safer, especially as I get older. On a recent trip to Western, Massachusetts it was raining very hard and I got a warning, the system shut down. On the return trip, everything was fine. My question is, did the system malfunction, get wet or doesn’t it work when I may need it the most? The dealer just shrugged off the question.
A. Like many newer cars, the pre-collision system uses a system of sensors, cameras or a combination of both. I have driven many Subaru vehicles in all kinds of weather and found that as good as they are, the advanced safety features are not perfect in all weather conditions. Not surprisingly snow is a problem if the cameras get covered. This is the same for heavy rain or even very bright sun. There is nothing wrong with your car, these pre-collision systems have limitations. Over time they continue to get better, but no system yet takes the place of an engaged fully aware driver.
Q. I recently purchased a 2015 and own a small Sunfish sailboat. I also have a small utility trailer. I used to tow both with my previous car which was mid-sized and had a V-6 engine. When I asked the dealer about towing with the Corolla they advised against it and suggested to buy a truck.
A. According to the Toyota parts supplier website the 2015 Corolla has a surprising towing capacity of 1500 pounds. With a properly installed trailer hitch you should be able to safely tow your trailers.
Q. I have a Chevy Tahoe that is setting a P0305 code. I replaced the fuel filter, plugs, and wires. Now it seems as if I have no compression in one cylinder. It is running very rough and sounds like an idling cement truck. When driving above 50-55 miles per hour it rides fine. Below that speed, it jerks uncontrollably, begins to hesitate, then stalls. What could it be? If it is the engine that is bad, does it make sense just swap the engine?
A. The first thing you need to do it determine if in fact there is low compression in one or more cylinders. The code is telling you the issue is with cylinder 5. A compression test or cylinder leak-down test will better determine what is wrong. From this point you should be able to determine if it is a lack of compression due to a valve or piston failure. The repair could be a valve-job or engine rebuild. Depending on the overall condition of the truck, a used engine might be the most economical repair.
Q. I have a 2010with 4-wheel drive and about 106,500 miles. When I am traveling at around the 35-40 mph there is a loud rumbling/vibration noise. It doesn’t happen when the car is accelerating from a stop and doesn’t seem to be there at highway speeds. The noise/rumble is just when slightly pushing the gas at 35-40 mph. The noise does not come from the engine area and it seems like it comes from the rear of the car. Any ideas?
A. I would start with an overall diagnosis of the vehicle. This should include a performance test of the engine. Something as simple as a slight engine misfire that might be enough to cause a slight shudder but not enough to set a check engine light. The other possibility is there is an internal transmission failure. Some Honda models (CR-V is one) had an internal failure that caused a fracture of a shaft support bearing/ring. The other less expensive issue is the rear differential fluid may need changing or may have been changed without using Honda fluid. A good technician should be able to find the source of the rumbling noise.
John Paul is AAA’s Car Doctor. He is an automotive expert who has been writing and talking about cars for more than 30 years. He also hosts the Car Doctor radio program on WROL radio in Boston. Email John at jpaul [at] aaanortheast.com.