Locating problem with scan tool

Q. I own a 2005 Saturn Ion with 28,500 miles. Under light acceleration I notice a slight jerk. I went back to the dealer and they could not find the jerk sensation. I have a 5-year/50,000-mile warranty. Do you have any suggestions?

A: The jerk you mention can be either the transmission torque converter going into its lock-up mode or an engine misfire due to an ignition or fuel delivery problem. A good technician can hook up a scan tool, take the car on a road test and monitor all engine parameters. When the jerk happens the scan tool and all engine and transmission parameters will be recorded. This will give the technician a good idea on where to look for the source of the jerk.

Q: I own a 2002 Acura MDX with 51,000 miles. My extended warranty expires in May 2009. The dealer says I cannot extend the warranty when this one expires. Do you know of a good warranty I can purchase?

A: Some car dealers sell non-factory warranties that are very close to the factory coverage. Extended warranties can be very pricey. If you feel more secure with an extended warranty, check with the local AAA office and ask them for a recommendation on a good company. Do not buy an extended warranty from a mail order or Internet firm.

Q: I own a brand new 2008 Mazda CX-7 with 6,300 miles. A local transmission company is offering a one-time charge for a yearly transmission fluid flush for the life of the vehicle. Would you recommend this service?

A: The service interval on your Mazda transmission is outlined in the owner’s manual. A yearly transmission fluid flush is not necessary on this vehicle. The average transmission fluid flush is every two years. Some new vehicles have a drain plug on the transmission pan similar to an oil drain plug. The technician can simply drain the transmission fluid out of the transmission pan and refill it. The amount of fluid will vary from 3 to 7 quarts, depending on the vehicle.

Q: I am interested in buying a programmer for more power and fuel economy for my diesel-powered 2008 Ford F-250. Which one is the best and do they actually produce as much power as they claim?

A: Power programmers will get you more power out of your diesel. You can reprogram the computer for a few different horsepower gains. The downside is the extra load you put on the engine from the added turbocharger boost. If you do decide to upgrade your truck or any diesel-powered vehicle, check out a complete kit including a larger intercooler, air-intake system exhaust and any type of water injection. All this combined should give you all you want and more. I recommend you check out the Gail Banks full system.

Q: I’ve been reading a lot lately on the Internet about hydrogen generators that can be installed in cars. The claims are that they are easy to install and improve gas mileage considerably. Are these credible claims? Are there any qualified mechanics who can install them?

A: There are many claims out there today to improve the internal combustion gas engine, as well as alternative power options, such as what you’re looking into.

I cannot at this time give you a qualified opinion on the hydrogen generator. However, before you purchase any products, make sure you’ve done your homework and talk with people who have already used them.

Q: Do you think that a steam-powered vehicle could ever be produced as an alternative energy type vehicle? The steam could be produced by gas or coal. A friend told me that most of the energy in the internal combustion gasoline engine is wasted.

A: The old steam engines and vehicles could never meet today’s standards. Internal combustion gasoline engines are very efficient, unlike engines with carburetors and old style ignition systems. Over the next few years gas mileage and emissions will improve even more. Hybrid-powered vehicles will also become more the norm than today.

Q: I have seen the Lucas fuel injector cleaner advertised, as well as other brands. What brand would you suggest?

A: There are many brands of fuel injector cleaners on the market. Make sure you do not buy a cheap brand. Lucas, Techron and Wynns have good fuel additives.

Q: I own a 1999 Ford Taurus V-6 with 70,000 miles. The gas mileage went from 20 miles per gallon to 13-14 mpg. There are no engine problems or lack of power. Why has the Taurus dropped so much in fuel mileage?

A: I hear a lot of complaints on loss of mileage. At 70,000 miles, we need to look on a scan tool and observe the front oxygen sensor operation. Oxygen sensors get lazy with years and mileage.

Make sure the transmission is shifting into overdrive and the brakes are not dragging. Tire air pressure should also be checked. Full synthetic oil can add up to 1 mile per gallon in fuel economy.

Q: I own a 1993 Volvo 850 GLT. A few weeks ago the speedometer and trip odometer stopped working. What should I do?

A: I looked on our Identifix Web site and found many replacement speedometer cluster assemblies. Alldata lists a complete step-by-step troubleshooting and removal procedure. Check out Alldata.com in the DIY section.

Junior Damato is an ASE-certified Master Technician. E-mail questions to info@motormatters.biz or mail questions to: Auto Doctor, 3 Court Circle, Lakeville, MA 02347.

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