Viewer-submitted questions for The Car Doctor:

Q: I have 2008 Toyota Highlander in which the car alarm goes off without anyone being near the vehicle. This has happened in the past but then stopped on its own. It’s been several years since this has happened, but it recently started all over again. The car alarm, which came with the car when I purchased new, goes off when the car is parked and locked. After a minute or so it turns itself off, only to do it again after 5 or 10 minutes. Yesterday the car did it all day, while parked in my driveway. It only does it if the car is locked. Thank you for any suggestions you might have.

A: The issue is usually a faulty hood latch, there is a switch in the latch that signals the alarm that the hood is being tampered with. You may be able to have someone bypass the switch, or you can replace the latch. Someone with a good scan tool can check to see what switch set off the alarm, but usually the latch is the issue.

Q: Thanks for all the insight and tips.  A fortuitous visit to my local Acura dealer last year landed me a 2020 CPO Acura ILX with only 2,900 miles on it.  I asked the dealer straight up if the 91 octane was required and he gave me your answer.  I compromised and have been using 89 octane since the day I drove it away and it runs just fine; gas mileage combined is around 28mpg. By the way, I’m a simpatico cheapskate like you and I use Stop and Shop reward points to reduce my weekly fill up by .30 cents a gallon at Shell stations, which almost brings it to the cost of 87 octane.

A: My answers to questions about fuel requirements usually come from the owner’s manual, but Acura wasn’t very helpful in this case. Their manual states “Some models require premium fuel and for others, it’s recommended. Consult your dealer for details.” It has been my experience that for most Acura models, premium fuel is only a recommendation and not a requirement.

Q: Suddenly, my engine of my older Toyota Corolla has a “puttering sound” to it, like a lawn mower. What could have possibly caused the change in sound?

A: From your description it sounds like the beginning of an engine misfire or perhaps an exhaust leak. In older Toyota models, a common problem is that when the flexible exhaust pipe starts to wear out, it will leak and the exhaust will get louder. At this point I would take the car to a repair shop for a full evaluation.

Q: I acquired my friend’s grandfather’s car, a 2004 Ford Crown Victoria LX Sport. Very few people are aware of the existence of this model; for all practical purposes it is a clone of the high-performance Ford Marauder. People are stunned when they look inside a Crown Victoria and see leather bucket seats with a floor mounted shift and a console. The car came with the air ride suspension which I learned usually fails somewhere after 100,000 miles. When that happened to me, a friend (a mechanical genius at 24 years old!) replaced the bladders with the coil springs from another vehicle.  It was complete in 30 minutes. You will be doing a great service to your readers if you let your readers know there are options to the expensive air suspension.

A: think you just did! Yes, there are alternatives to factory air suspension on many vehicles. There is an online company called Strutmasters (as well as others) that sells complete kits, springs, shocks, struts and coilover shocks which can be a cost-effective alternative to factory air suspension.

Q: I’ve heard a lot about the new Mazda CX-90. I currently own a Mazda CX-9, which has been a good car. Is the CX-90 better, worse, or just a rehash of the same car?

A: I recently road tested the Mazda CX-90 and found it to be a very good car. This may be the biggest Mazda that I have ever evaluated and a completely new model. In the case of my test car, it sat seven in three rows of seats with two sets of captain chairs. My tall rear seat passenger found the head room a bit tight but the seats very comfortable. The test car came with a mild hybrid, straight six-cylinder engine (I believe a first for Mazda), which performed well. The interior was quite luxurious with suede material used throughout.  My only nits to pick are I was not a fan of how the shifter operated and the advanced driver assistance system at times seemed overly intrusive. 

Q: I was looking for new wiper blades at my local auto parts store and came away confused. I saw beam blades, hybrid blades, conventional blades, dual blades and some that were impregnated with some kind of silicone. Also, the prices of the blades ranged from $10 to $40. What are your thoughts on wiper blades?

A: When it comes to wiper blades, I tend to be a brand name buyer, and I use Trico Exact Fit or Bosch blades. Winter blades can be great in the snow belt, although I tend to stay with a hybrid blade. I stay away from novelty blades (weird colors and dual blades) and I find that bargain blades chatter. Although I haven’t tried them, the Rain-X blades get good reviews.

Do you have a car question? Email the Car Doctor for a personal reply.

If you’d like more information, head to AAA Northeast.