Dear Doctor: My 2007 Pontiac Grand Prix is making a popping noise from the front driver's side when driving straight at speeds above 55 mph. I have replaced both inner tie rods and the hub bearing, but the noise is still present. Do you know what causes this? -- Dylecia
Dear Dylecia: A commonly overlooked issue in GM's front suspensions are worn bushings on the lower control arms. They can cause the noise that you mention. Sway bar links and bushings also can cause noise.
Dear Doctor: I have a 2002 Honda Accord with 107,000 miles. It continues to have starting problems despite several visits to the dealer and local service shops. The dealer ruled out the keys. They replaced the main fuel relay, which had been previously replaced, but it was aftermarket. They removed the aftermarket alarm and wiring and re-secured as it should be. The car worked for two weeks but the problem returned. They then replaced the electrical portion of the ignition What should I do next? -- Levy
Dear Levy: You need to find another shop or dealer to properly diagnose this car. A no-start condition should not be a major problem. The technician will connect a scan tool, spark tester and fuel pressure tester and monitor all sensors when cranking. Loss of spark is a common fault in these older Honda vehicles. We use both Identifix and Alldata when we run into problems like this on a regular basis.
Dear Doctor: I have a 2000 Nissan Altima with 80,000 miles that shakes when starting up or when reversing. When the 'check engine' light came on I took my car to the garage where the mechanic hooked it up to a computer. He said the last two cylinders are not firing up. He also gave the battery a boost in order to get the reading. His suggestion is to replace the engine. A different shop has recommended an engine diagnostic service, along with an air filter, belts and two front tires. What should I do? -- Elizabeth
Dear Elizabeth: The first step should have been to go to a shop that has ASE-certified technicians. Before putting on tires -- or any other service -- is to find out why the engine is not running on its cylinders. At 80,000 miles, I find it hard to believe the engine needs replacement. The most common problem on this vehicle is a leaking intake manifold gasket. A good technician will be able to find the problem within an hour of diagnostic time. Using a scan tool the technician can look at all of the engine values.
Dear Doctor: I have a 2010 Chrysler Town & Country with warped rotors. Would slotted or drilled rotors help to prevent warping better than conventional rotors? -- Gene
Dear Gene: Anytime you upgrade to a quality aftermarket brand for brake rotors the chance of rotor warping will lessen. You must also make sure the rear brakes are contributing to stopping the vehicle.
Dear Doctor: I have an ongoing problem with a leaking gear selector shaft seal on the automatic transmission in my Pontiac Trans Am. I was told that the hole where the shaft goes into the transmission housing has been enlarged by years of use, which is the reason the selector shaft seal does not stop this leak. What's my solution for this problem? -- Francis
Dear Francis: If the transmission selector seal area has been elongated or oversized, then you must remove the transmission pan and wash off all of the fluid from the seal area. Clean the seal area with carburetor cleaner and let dry. Coat the outside of the seal with two-part epoxy and install the seal into the transmission and let sit for 24 hours. This will give enough time to allow the epoxy to dry and fill the gap between the seal and transmission.
Dear Doctor: Have you driven the new 2014 Acura RLX? I'm interested in how it handles. -- John
Dear John: Some new car and truck models are just refreshed versions, but not so with the 2014 Acura RLX. The RLX replaces the RL, which has been around many years. Our test car had P-aws (Precision All-Wheel Steer) which has two small electric motors that actually move the rear-wheel toe adjustment individually to enhance handling. There is also a Sport Mode that changes the steering effort and quickens the response of the engine. There is plenty of smooth power throughout the rpm range on this 310-horsepower V-6. The tester's base price was $49,400, and fully optioned at $61,400.