Timing Belt Change Intervals — Done By Years or Mileage?

April 10, 2010/Steve Tackett

MOTOR MATTERS ASK THE AUTO DOCTOR BY JUNIOR DAMATO

Dear Doctor: I own a 2004 Kia Sorento with only 35,000 miles on the odometer. Should I have the timing belt changed? The Kia dealer told me that I should have it changed, even though the manufacturer recommends the timing belt be changed at 60,000 miles. I need some advice with this one. What is it — miles or years? Robert
Dear Robert: My recommendation is to change the belt at the average span of five years, even if the engine is not at the mileage interval recommended by the manufacturer. The timing belt is like a big rubber band. If the belt breaks on your vehicle, then there could be severe internal engine damage done to the valvetrain. There could even be piston damage.
Dear Doctor: I have a 1994 Ford Probe that I use only occasionally. When the Probe is not driven for a week the battery goes dead. My mechanic is unable to find the problem. What tests should be performed in order to trace this problem? The car rides fine, except for this battery problem. Ira
Dear Ira: The battery should not go dead in only one week — four weeks, maybe, on this vehicle. The first step is to check the battery condition. Then check for parasitic drain. This is done with a digital amp meter connected to the battery and the battery cable. The technician will check for how much drain is in the system with the key off and all doors shut. Fifty mili amps is the maximum draw on this vehicle. Less would be better. I have seen things from a small glove box light, hood or trunk light cause this problem. Everything that has retained accessory power with the ignition key off is suspect.
Dear Doctor: I own a 2007 Acura RDX with the turbocharged four-cylinder engine. This is my second Acura. There is an intermittent whining noise. The technician did hear the noise, but could not determine the origin. He told me it could be the anti-lock brake system priming itself. Have you encountered this problem? My fear is that resale could be a problem. Linda
Dear Linda: Intermittent noises can be difficult to locate unless the technician can actually hear the noise during the testing.

2004 Kia Sorento

If the dealer’s technician cannot locate the noise, then check with AAA for AAA-approved repair shops in your area so someone else check the car. Whining sounds are usually from belt-driven accessories, such as the power steering pump, alternator, even the air conditioning compressor.
Dear Doctor: I own a 2009 Toyota Tacoma pickup truck with the V-6 engine. I added a 3-inch “cat” back exhaust and a K&N air filter. Should I have the dealer reprogram the computer for the added parts? Buzz
Dear Buzz: There are no factory reprogramming options at this time for the performance parts. You will have to check with aftermarket programmers, such as Super Chips in Florida. There are companies that specialize in specific brands. In some cases you can remove the computer and send it to the company and they will modify the computer program.
Dear Doctor: My Ford Ranger has 180,000 miles and is in great shape, including a new “Jasper Engine” installed last year, so total miles on the engine are about 10,000. Gas mileage has always been poor (8-13 mpg). My son and I changed all three oxygen sensors and the mileage seems to be improving to about 17 mpg. My son wants to put an aftermarket exhaust system and intake system on the truck for improved sound and “coolness.” I’m thinking a new “cat” is probably in order. What would you advise? Rob
Dear Rob: There is no question that at 180,000 miles on the exhaust system, including the catalytic converter and oxygen sensors, there is wear. The oxygen sensors get dirty and lazy. The catalytic converter gets partly blocked, causing extra back pressure. A back pressure tester is used to check actual pressure in the exhaust. The use of a low-restriction system with a new correct size catalytic converter will get you improved performance and gas mileage. A clean fresh air intake system will also help. — Junior Damato, Motor Matters

Junior Damato is an ASE-certified Master Technician.

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Copyright, Motor Matters, 2010