Dear Doctor: My 2011 Chevrolet Impala V-6 makes an intermittent scraping noise in the front passenger wheel. The scraping sound occurs sporadically when making a turn from a complete stop and the wheel is turned. When accelerating, the scraping sound occurs for a few seconds, and the car will not move. The transmission only engages when the scraping sound stops. The following code had been retrieved from memory: DTC c0040, p0016, p0011, p0030, p0036, p0053, p0054, p0101, p2270, and p2271, after an ABS warning display. Can you help? NW
Dear NW: The noise when turning the right front wheel could be related to fault code c0040 (ABS signal fault code). The confusing part is you mention the transmission does not engage, and this could be a fluid level or filter problem. Get the car test-driven by an ASE-certified technician. The codes p0016 and p0011 are camshaft position related, the p0030, p0036, p0053, p0054, p2270, and p2271 codes are all oxygen sensor related. The p0101 is mass-air-flow related. Before any parts are replaced, the systems should be checked for power and grounds. A broken wire in a harness can cause multiple error fault codes. As for the right front ABS code, both the hub bearing and two-wire connector should be checked as well as the A/C signal emitting from the hub bearing assembly.
Dear Doctor: As a city driver who only does stop-an-go local trips, I started following your advice on getting out on the highway for a 20-minute drive to get the engine up to temperature, as well as dry out the exhaust system. Recently the temperature dropped well below freezing for several days, so I only let the car engine run in the driveway for 15-plus minutes, but did not drive it out on the road. Am I doing more harm than good by warming the car up and not using it? Claire
Dear Claire: It’s better to drive the car because the normal water buildup in the exhaust from the engine running may not otherwise burn off and blow out the tailpipe. The water, which is a by-product of internal combustion engines, could freeze in the catalytic converter and muffler and actually block the exhaust from exiting the system. I have seen this many times in cold weather and cause a no-start condition.
Dear Doctor: I have a 2010 Scion TC with about 42,000 miles on it. I change the oil every four months. About 18 months ago I received a letter indicating my engine could have an oil consumption problem. Toyota did the test when the car had about 34,000 miles and found the piston rings were faulty and replaced them. Then 1,200 miles later, I was hearing terrible sounds, which the dealer determined to be poor oiling and replaced the block. Pistons #2 and #4 were ruining the walls and were showing worse wear as the piston number got higher, so they installed a short block (lower half of the engine). Then 1,500 miles later, the counter balance shaft bearings/sleeves were making noise and they were replaced. Finally, with all the articulation, both CV boots tore, leaked grease, and were replaced by the dealer. When I open the oil cap, I can feel puffing of air, which I think is blowback. With a rebuilt lower half and new pistons, is this normal? Frank
Dear Frank: A small amount of pressure is normal when the oil cap is removed and the engine is running. There have been some oil consumption problems with Toyota four-cylinder engines over the years. Personally, I don’t understand why Toyota doesn’t replace the entire engine vs. making patchwork replacements of a few parts that can inconvenience the owner.
Dear Doctor: We purchased a Toyota Highlander Hybrid three months ago and absolutely love everything about it, but I’m wondering if a sudden drop in fuel economy should be a concern. We’ve been driving very conservatively, trying to see exactly what we could eke out of this vehicle, and, as everything broke in, saw a steady increase up to 27.8 mpg. But since our 5,000-mile checkup at the dealer — which coincided with a winter cold snap — mpg suddenly dropped to 27.2 and has alternated between that and 27.3 for almost a month. I know a drop of 0.5 mpg is minor, but is it just the cold weather or something else? David
Dear David: This is normal. Fuel economy will always decrease when the temperature drops below freezing. Engines run cooler and richer, the heater blower motor is on, and operating the rear window defroster and head lights requires power that comes from the alternator, not to mention that the hybrid system may not operate at 100 percent in extreme cold and may not go to full charge in below-freezing temperatures.
Dear Doctor: Is there a need to still use dry gas in today’s cars during the cold winter months? Fred
Dear Fred: I do not recommend the use of any gasoline antifreeze, unless there is water in the fuel. If you want to use a gas additive, then use any one of the many products available at auto parts stores that fight carbon buildup and clean the combustion chambers and fuel injectors.
— Junior Damato, Motor Matters
Copyright, Motor Matters, 2018
(Manufacturer photo: 2011 Chevrolet Impala)
Junior Damato is an ASE-certified Master Technician.
E-mail questions for publication to [email protected]