Dear Doctor: I own a 2002 Acura MDX with 58,000 miles. I took the vehicle to the dealer for a brake replacement. They replaced the pads and cut the rotors and replaced the brake fluid. Since this service was performed, I've noticed a humming sound when I step on the brake. I took it back to the dealer and they re-cut the brake rotors again. The noise is not as loud now, but there was never any noise before the brake replacement. What can be done to correct the noise? Mark

Dear Mark: The first mistake was to resurface - or cut - a good rotor. The humming sound is coming from a coarsely cut rotor. It may have been cut too fast or with a dull cutting tool. Unfortunately, the rotors may now be too thin to resurface again. The correct way to resolve the problem now is to replace all four rotors with new ones - at no cost to you. If any one wants to talk about this with me personally, please me join me Saturday mornings on my Internet show from 7 a.m. to 10 a.m. eastern time at www.1460wxbr.com for live talk.

Dear Doctor: I own a 1998 Chevy pickup truck with only 68,000 miles. It does not start up. I replaced all the tune-up parts. The engine still will not start. I asked some shop mechanics and they said it could be a timing chain or catalytic converter. What are your thoughts? Buddy

Dear Buddy: Before replacing any parts you should have checked for spark and fuel pressure; for without either one of these the engine will not start. The computer system may not store any fault codes. As for a timing chain or catalytic converter fault, at 68,000 miles I do not think this is the case. A check of all power, ground and all fuses is also recommended.

Dear Doctor: I'm very interested in buying a brand new Dodge Challenger SRT8 with the six-speed manual transmission. What are your thoughts about Chrysler still servicing cars in a few years? What do you think about the Challenger SRT8? Stephen

Dear Stephen: Even though Chrysler is undergoing a big transition, the automaker is still in business and is not going away. I drove the 2009 Dodge Challenger SRT8 six-speed manual with the Track Package at $44,395 (an option I recommend you get). The Challenger is not the fastest of three main muscle cars, however it is the largest and can seat two people in the back seat. One great feature is anti-back roll back hill control, which stops the car from rolling backwards on a hill when you take you foot off the brake pedal while keeping your foot on the clutch.

Dear Doctor: I own 2006 Saturn Vue V/6 automatic. I sometimes have a problem with the car maintaining consistent speeds. I have been back to the dealer three times, but there are no fault codes stored in the computer. Do you have any suggestions? John

Dear John: Take the car to any good shop that employs ASE-certified technicians. You can also contact the local AAA for a list of AAA-approved repair shops in your area. I suggest you leave the car with a shop and let a technician drive it while he has it connected to a scan tool. If the problem happens while he is driving, he'll push on the scan tool record button to make a recording of the event. The technician can then review the information for corrective repair action. There are no Technical Service Bulletins on this issue with your Saturn.

Dear Doctor: My car was hit and twisted and I lost two tires. I took it to a nearby college automotive class and they did all they could for it, but it still has drivability problems. At first while driving on rough streets I would smell burning rubber. I took it to two reputable shops that found nothing wrong with it. After driving it around for a while it now sometimes has a light odor. Please advise what I should do. Perlie

Dear Perlie: For the burning smell the first step is to look under the car and see if there is any plastic on the exhaust system. Next, look for any oil that may be on the exhaust as well. A trip to a shop that employs professional body experts would be a good idea for a second opinion. Check with the local AAA office for a list of AAA-approved shops.

Junior Damato is an ASE-certified Master Technician.

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