Dear Doctor: I bought a Cadillac 2007 DTS new and today it's my "Sunday Driver" with only 27,000 miles. The battery seems to be fine, but should I wait for it to go dead or change it at some point? Also, I go to Florida for three months in the winter and have been hooking up a battery maintainer. Is this a good idea? -- Ben
Dear Ben: For my neighbor who owns a 2008 DTS and goes south for six months, I lift the rear seat cushion and disconnect the negative battery cable in November and reconnect it in April and connect a battery maintainer until the battery is charged. As for replacing the battery, the average battery life is 3 to 4 years. Have the battery checked before replacement. Your battery, if original, is 5 years old and considering all of the electronics in that car, it would be a good idea to replace it now.
Dear Doctor: My son has a 2004 Hyundai Santa Fe with 100,000 miles. Occasionally, when turning the key in the ignition, there's no cranking of the starter, yet all of the dashboard lights are on and the radio and lights work. Out of frustration he hit the steering wheel and then tried the key again and the car started. My mechanic replaced the ignition switch and starter. For several weeks there was no repeat of the no-start condition, but then it happened again with the same results: hit the steering wheel and restart the car. Any suggestions? -- Frank
Dear Frank: The first step is to check the connections at the battery and cables leading to the engine block and starter motor. You can have the technician hook up a small test light to the (S) terminal at the starter and temporarily mount it so the driver can see it when trying to start the engine. There are many relays and electrical connections that can effect starting. Often overlooked is the ignition switch and neutral safety switch. These can be checked for terminal connections.
Dear Doctor: I have a 2009 Chrysler Town & Country and had the brakes checked. The front ones were replaced, got new calipers and caliper line replaced. I still hear a high pitched squeal and scrape when I apply the brakes. What should I be checking for? -- Charles
Dear Charles: First you need to find which brake is making the noise. Second, make sure the shop used a quality brake pad and applied an anti-squeal compound on the back side of the pads. An occasional brake squeal is not unusual.
Dear Doctor: I have a 2004 Infiniti I35 with 75,000 miles. At about 50,000 I noticed it was starting to ping. I've always used premium fuel and have tried several different brands. I have also used many bottles of Chevron Techron in the tank with no help. Finally, I had the fuel injection system professionally cleaned by the Nissan dealer. Again no help. I do understand that a light ping at times is normal but this is much worse than a light ping and it never did so prior to the 50k mark. I know that this can eventually cause serious damage and would like to get this matter resolved. Thanks for your advice. -- Bill
Dear Bill: I researched your issue on Identifix and found EGR sensor faults, lean fuel conditions and carbon build-up. Is the engine thermostat working correctly? Have the technician check the engine compression. If the compression is higher than 185 pounds, then a de-carbon treatment is needed.
Dear Doctor: I own an old big block 1969 Chevy Camaro SS 396 convertible. In traffic it'll start to heat up. What's a good, safe temperature to run it up to? I've run mine up to 240 because I had no choice, but in general, mine stays 220 or below. Is there a safe temperature to run up to in bumper-to-bumper traffic or around-town driving? -- Bill
Dear Bill: Old big block engines do run warm in traffic. At 240 degrees the engine is hot and as long as you do not run it hard at this temperature there are no long term problems. Does the car have a large electric fan? Did you use an open thermostat restrictor vs. a 160-degree thermostat? You can remove the center of the thermostat and use the base as a restrictor. -- Junior Damato
Junior Damato is an ASE-certified Master Technician. Email questions to email@example.com. Mail questions to: Motor Matters, PO Box 3305, Wilmington, DE 19804