Q-I recently purchased a 2010 Hyundai Genesis Coupe with the turbocharged 4-cylinder engine. In poking around the Internet, I have come across sites selling chips that are guaranteed to increase mileage and power without voiding the warranty. Sounds too good to be true. Would appreciate your opinion.
— J.S., Orlando, Fla.
A-You are wise to question claims that sound too good to be true. Tampering with the emission controls can get you into trouble with the law or with the inspection program, if it is discovered. Some aftermarket parts are OK while many are not. How can you tell? See if the item is CARB-approved. If it passes muster with the California Air Control Board, you’re safe. CARB is stricter than the federal EPA.
Q-I am very disappointed in you. Your answer to the tire question prevaricated and then passed the buck. Answer the question: Why does this common 4-cylinder Camry need V-rated tires?
— J.B., Chicago
A-I didn’t and it doesn’t.
Q- I have a certified pre-owned 2003 Camry which I bought from a Toyota dealer in March 2005. It had 25,000 miles on it. Now, almost six years later, I am a little short of 45,000 miles. The service guide uses both time and mileage, but this car is nearly 72 months old. Which do I follow, that for 44,500 miles or that for 72 months?
— J.F., Menomonee Falls, Wis.
A-Always select the farthest out service number. In your case, that would be 72 months. Some items, such as coolant, are serviced based on age, others are based on mileage, while others are based on age and/or mileage.
Q-We have a 2004 Honda Odyssey and our only real complaint with it is that there has always been a lot of road noise in the cabin. It’s bad enough that at highway speeds it’s a battle to see if we can turn the radio loud enough to hear it without making the passengers deaf. Are there any after market solutions that really work for this type of problem?
— J.S., Lombard, Ill.
A-We are aware of neither an interior noise level standard nor reported measurements of noise. That’s probably because the issue is so complex. There are engine, road and wind noises and they vary depending on a myriad of conditions. Extra (fireproof) batting in the engine compartment and behind the dash might help.
In a paper presented to the Society of Automotive Engineers (SAE), Haruki Saito and Toru Mori of the Isuzu Advanced Engineering Center wrote: “In the case of vehicle body vibration due to forces applied at the engine over a wide frequency range, accurate prediction and analysis are difficult to achieve using conventional numerical and experimental modal analysis methods. … Using the results of interior panel vibration measurements in a vehicle model, enormous amounts of time are required to measure on each panel in the passenger compartment.”
In other words, this is a daunting task. Test drive a vehicle under all the conditions you normally drive before buying. Ask to keep it for a day or two. Ten minutes around the block with the salesman jabbering in you ear doesn’t cut it.
Q-We bought a cream-puff, one-owner 1999 Subaru Legacy wagon with 88,000 grandmotherly miles on the clock. The automatic transmission will at times downshift from overdrive into 3rd, stay in 3rd for a minute or so, and then upshift back into OD. The previous owner had taken this car into a Subaru dealer at 56,000, but “the problem could not be replicated.” This car has been assiduously maintained with regular scheduled transmission flushes. I took the car to a transmission shop which dropped the pan and replaced the OD solenoid, to no avail. Would “re-flashing” or reprogramming the computer fix this problem? If so, how is this done?
— R.F., Harwington, Conn.
A-The transmission control module (a computer) controls gear selection and torque converter lock-up for overdrive. It relies on inputs from the throttle opening, vehicle speed, engine speed, and gear selector position. Various sensors and switches located on the vehicle feed information to the TCM which then makes calculations based on all these inputs. What this boils down to is a diagnostic challenge. Allow you favorite shop to keep the car a few days and drive it to see the problem firsthand. Reflashing the computer might help, but we have not found any bulletins showing program updates.
Q-I have a problem with my 1995 Mercury Grand Marquis. When I accelerate I hear a wheezing noise for a short time as if the engine sucks in extra air. What could the problem be?
— G.A., Arlington Heights, Ill.
A-This is a common problem on the 4.6-liter V-8 engine that often triggers the check engine light as well. There is a vacuum tube that runs from the PCV valve on the right side valve cover over to the throttle body where it connects with a formed rubber elbow. The elbow fails.
Q-I purchased four snow tires with rims for a 2004 Chrysler Crossfire. I traded in the Crossfire for a BMW Z4. My question: Can I use the tires from the Crossfire on the BMW? Both cars are terrible to drive in winter weather, especially snow. I slip and slide all over the place.
— K.U., Chicago
A-We checked our cross reference sources and it appears that the tire sizes do not match. Of course, we did not compare the Crossfire to every iteration of the Z4 of which you did not provide the year or model. Put them on eBay or find an online Crossfire car club and post them for sale.
Bob Weber is an ASE-certified master automobile technician. Send questions to Motormouth, Rides, Chicago Tribune, 435 N. Michigan Ave., fifth floor, Chicago, IL 60611, or e-mail with name and town to motormouth.trib@verizon.net.
