Question. I have a question about the tire-pressure indicator light in my 2007 Subaru Outback. After anywhere from 8 to 15 miles of driving, the tire-pressure indicator starts flashing and continues to do so until the trip is over. The pressure in all tires is fine, and even a short interruption of my travel with the engine off would cause the light to stop flashing, only to reappear after a while. Any suggestions?
a. There are two types of tire pressure sensors (TPMS) direct and indirect. Indirect sensor vehicles use an anti-lock brake system that has no physical components at the wheel. Your Subaru uses the direct type which uses a wheel mounted battery operated sensor. More than likely one or more tire pressure sensors have failed. These battery operated sensors have an expected lifespan of 7-10 years. When the battery is weak it cannot send signals to the cars computer and the light flashes to indicate a system malfunction. Subaru TPMS costs about $75 each plus installation. There are also aftermarket sensors that are cheaper. TPMS is a safety system, check tire pressure monthly until you get the system repaired.
Question. 83,000 on my 2013 Honda CR-V. The car drives fine, but there is a rattling sound especially on rough roads. Last oil change I asked mechanic to check it. He said there are plastic clips (forgot what) that come loose, and he tightened them. It still makes noise.
A. Rattles are a difficult problem to diagnose, but Hondas have some common rattles.
The catalytic converter heat shield (the exhaust part) could rattle – it would be a crackling sound coming from under the car. A different bumpy rattle in the car could be part of the heater called the heater core and Honda’s fix was just to add foam insulation (a fair amount of work). If it were my car, I would check all the steering and suspension parts, the 8 year old was a strut/shock weakening or one of the mounts could have started to wear. I just want to rule out any security issue. I’ve found that apart from a good road test, the best style shop lift to check for rattles is a drive on lift. On this type of lift, all the weight of the car is seated on the tyres, as on the road. There are also special tools to find rattles (one is an electronic listening device called a chassis ear. It doesn’t take much time to find the rattle easy and clear. Finding a rattle after that can be expensive. It’s those cases) There may be one where if it’s not dangerous, let time be your diagnostic tool and wait until the noise becomes a little more obvious.
Q. Somebody told me to leave the wax for 12-18 hours while waxing the car and take it off for a good shine. Is it true? Also, what do you think of machine buffers for applying and removing wax, I see pros using them all the time.
A. When waxing in a car, apply the wax to a square of about two feet and remove the wax as soon as it becomes cloudy. Then continue to slightly overlapping areas. Where there is confusion, some people want a deeper shine and in that case, wait a day before applying a second coat of wax. With regard to buffing wheels, the safest and easiest to use are dual-action buffers. High speed buffs work great, but without proper care you can easily burn through the paint. If investing in a buffer, it has been my experience that the more you spend, the better the result.
Q. I have a new car and the dealer recommends nitrogen in the tyres. The cost was about $75 and was included in the financing, but I said no. Now I’m wondering if I should have added nitrogen to the tyres. Is nitrogen better than using regular air?
A. Air is 78 percent nitrogen and I’m cheap and would never pay $75.00 for something you get for free. There are special applications that nitrogen is preferred because it is a dry gas and can contain moisture in compressed air. These specialized applications include tires for racing, military and commercial aircraft and even spacecraft. So, unless you’re running or taking your car into orbit, say no to nitrogen.
Q. An evergreen tree has left a sticky sap on the hood of my car. And I’m having a hard time removing it. Which one should I use Does it require professional description?
a. Start by washing the car with warm soapy water (only use car wash soap) and once dry use a special bug, tar and sap remover. Clean the car again to bring back the shine using the cleaner once. If that doesn’t work, a professional detailer should be able to remove the sap and restore the finish. The longer the juice is in the sun, the more difficult it will be to extract it.
Question. I’m not sure if you’ve tested polish, wax and ceramic coatings. Which consumer ceramic coating do you recommend? I’ve used Mother’s Ceramic with great results (and it’s very easy to apply) but auto parts stores have a whole shelf of products. any preference?
a. Basic ceramic coatings were difficult to apply, expensive and not best left to the professionals. They also needed some tedious paint correction before they could be applied. Some basic ceramic products were $250 or more for a single use and could cost $750-$1000 when applied professionally. Quite expensive, although you need to do it once every five years. Today ceramic spray products are a hybrid of sorts, Mothers is a good product with an affordable price from Chemical Guys and Meguiars.
–John Paul, senior manager, public affairs and traffic safety, AAA Northeast