Q: I recently had the transmission in my Chevy Impala (51,000 miles) power flushed at a local Goodyear dealer. The technician told me it was not necessary to also replace the filter since the equipment they used (Wynn’s) would also clean the existing filter. I went along with this explanation. Now, in mentioning this to my somewhat knowledgeable son, he told me I was given bad information and wasted my money since the filter would still have retained contaminants. What do you say? -- A.G., e-mail

A: A.G., I’d agree that you received poor information from that technician. But I don’t believe you wasted your money. Just so you know, there’s no way to flush contaminants out of the filter with transmission flushing equipment. But, I’m a believer in power flushing the transmission, especially when the old fluid is discolored. That’s because the old-fashioned method of servicing the transmission fluid involves removing the transmission pan. This method only removes about one-third of the fluid in the system and the other two-thirds remains in the torque converter and transmission cooler. The best way to remove all the fluid is by flushing. If the old fluid in your Impala wasn’t that bad, you likely don’t have enough contaminants trapped in the filter to cause trouble. But, if you need piece of mind, go ahead and have the filter replaced. To do so, the transmission pan will need to be removed.

Q: I own a 2004 Honda Accord with 97,000 miles on it. My manual says at 105,000 the timing belt needs to be replaced which will cost me about $400-$500. How critical is that 105,000 mile figure? If I choose to wait to change it at 110,000 miles would I be facing dire consequences? I am thinking of trading the car in 3-4 months when the new 2009 model comes out. I will have about 105,000-110,000 miles on the car by that time. What do you think? -- D.T., Elwood

A: D.T., Save your money and keep driving your car. I wouldn’t necessarily say that, though, if your Accord had an interference engine. An interference engine is an engine with very tight clearances between the pistons and the intake and exhaust valves. When the timing belt or timing chain breaks on an interference engine, the pistons usually damage the stuck open intake and/or exhaust valves. Sometimes the pistons become damaged, too. As a result, the cylinder head(s) need to be removed and the repairs become very, very expensive. More expensive than if the timing chain or timing belt had been replaced at the recommended interval.

The engine in your Accord, though, is not an interference engine and won’t be damaged if the timing belt breaks while driving. But, if it does break while driving, the engine will stall and you’ll need a tow truck. In your case, though, I wouldn’t worry. I’ve seen original timing belts last a lot longer than the manufacturer’s recommended replacement interval. For those motorists that don’t know if their engine is an interference engine, ask your technician. If your engine is an interference engine, my advice would be to replace the timing belt or timing chain at the recommended intervals to avoid potentially costlier repairs.

AutoAdviser: Ira Siegel is an Automotive Instructor and ASE Certified Master Auto Technician. If you have auto-related questions for Ira Siegel you can call and leave your questions at the Auto Adviser Hotline at 708-633-6839 or e-mail a question to Autoadvisr@aol.com.