2007 Chevrolet Impala Ltz Sedan 4-door 3.9l on 2040-cars

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Fullsize GM SUVs have a problem that's making owners sick

Some fullsize SUV owners are getting sick, thanks to a buffeting and vibration problem in 2015 model year examples of the Chevy Tahoe and Suburban, Cadillac Escalade, and GMC Yukon. According to owners' complaints to the National Highway Traffic Safety Administration, the issue can vary from an annoying vibration inside the cabin to an experience so severe that it leads to dizziness and headaches. General Motors is aware of the complaints, but the fix isn't so simple. According to spokesperson Tom Wilkinson to Autoblog, the company "has been tracking this issue for a while." The problem has a fairly low incidence rate, but when it does occur the issue can be "uncomfortable and annoying for owners." There's no precise cause for the issue, Wilkinson claims, and in some cases, simply balancing the tires or changing the door seals can make it go away. However, not all of the fixes are so simple. AutoGuide dug deep into the problem and discovered a GM preliminary information bulletin that advised dealers to remove the headliner and to check the roof's bonds to the bows that go across the vehicle. However, that document included a note that the solution might not entirely eliminate things. According to AutoGuide, adding Dynamat insulation to the roof sometimes helped the problem. A GM spokesperson also told AutoGuide the company fixed the problem at the end of the 2015 model year, and didn't go into any more detail. This roof issue seems linked to some of the worst droning in these SUVs. According to one complaint from a 2015 Suburban owner to NHTSA: "Roof will not remain attached to the roof bows. This causes the buffeting similar to a window being down when all are up. The results span from annoying to painful." A 2015 Yukon owner claims to have another alleged cause for the problem in a NHTSA complaint from February 2015. This person brought their SUV to the dealer seven times over the course of four weeks for vibrations. The dealer replaced the driveshaft, suspension components, and more, but nothing worked. According to an engineer to the service adviser: "In an effort to prevent roll overs, they designed the frame and body mounts too stiff. There are 40 engineers working on issues, they have no solutions that work across the board." Wilkinson told Autoblog that GM is working with customers on an individual basis to rectify things. Since these are newer vehicles, dealers should also fix the problem under warranty.

What if the mid-engine Corvette is really a Cadillac?

Call me crazy, but I'm not convinced the mid-engine Corvette is the next Corvette. The rumor is strong, yes. And, contrary to some of the comments on our site, Car and Driver - leader of the mid-engine Corvette speculation brigade - has a pretty good record predicting future models. But it's another comment that got me thinking: or maybe it's a Cadillac. There is clearly something mid-engine going on at GM, and I think it makes sense for the car to be a Cadillac. First off, check out how sweet the 2002 Cadillac Cien concept car still looks in the photo above. Second, there are too many holes in the mid-engine Corvette theory. There are too many holes in the mid-engine Corvette theory. The C7 is relatively young in Corvette years, starting production almost three years ago as a 2014 model. Showing a 2019 model at the 2018 North American International Auto Show would kill sales of a strong-selling car before its time. Not to mention it would only mean a short run for the Grand Sport, which was the best-selling version of the previous generation. More stuff doesn't add up. Mid-engine cars are, in general, more expensive. Moving the Vette upmarket leaves a void that the Camaro does not fill. There's not much overlap between Camaro and Corvette customers. Corvette owners are older and enjoy features like a big trunk that holds golf clubs. Mid-engine means less trunk space and alienating a happy, loyal buyer. Also, more than 60 years of history. The Corvette is an icon along the likes of the Porsche 911 and Ford Mustang. I'm not sure the car-buying public wants a Corvette that abandons all previous conventions. And big changes bring uncertainty - I don't think GM would make such a risky bet. Chevrolet could build a mid-engine ZR1, you might say, and keep the other Corvettes front-engine. Yes they could, and it would cost a ton of money. And they still need to fund development of that front-engine car. I highly doubt the corporate accountants would go for that. But a Cadillac? Totally. Cadillac is in the middle of a brand repositioning. GM is throwing money at this effort. A mid-engine halo car is the just the splash the brand needs to shake off the ghosts of Fleetwoods past. And it's already in Cadillac President Johan De Nysschen's playbook. He was in charge of Audi's North America arm when the R8 came out. A Caddy sports car priced above $100,000 isn't that unreasonable when you can already price a CTS-V in that range.

How GM engineers are using diaper 'snow' to keep you warm

Testing how snow affects General Motors' vehicles isn't really a problem right now for the company's engineers, but in the dog days of summer the process isn't exactly easy. The only real option is for them to book time at the automaker's climatic wind tunnel. However, a flash of brilliance from an engineer allows snow to be simulated regardless of the temperature outside, and the discovery is all because of his daughter's wet diaper. The realization came to GM Thermal Systems engineer Nicholas Jahn while he was swimming with his daughter and noticed how her diaper ballooned in size in the water. He found out the substance that makes this possible is called sodium polyacrylate. When the material gets wet it grows and forms fluffy flakes that are a close imitation of snow. Best of all, the stuff can be prepared easily any time of the year, and it's reusable. The engineering team uses the material to test the effectiveness of the heating systems of GM's vehicles. They spread the sodium polyacrylate over the inlets at the base of the windshield to obstruct the airflow and then crank the heater. After some time, they can see how much is being sucked into the system and design more efficient systems in the future. See how the process works in the video above and read about the diaper discovery in GM's press release below. Diapers Change Chevy Cruze Winter Warm-up Time GM validation engineer uses diaper material "snow" to reduce frigid drives 2015-01-06 DETROIT – An item commonly found on an infant's changing table is helping General Motors' engineers simulate snow year round, ensuring heating systems in cars like the 2015 Chevrolet Cruze can quickly and efficiently warm its interior. Packed snow can prevent air from entering the inlet panel at the bottom of the windshield, obstructing the flow of air into the heating system and reducing the amount of air it can push out. This can lead to less efficient warming of the car's interior and windshield defrosting. "The last thing anyone wants to do when it's freezing cold out is scrape their windshield," said Nicholas Jahn, GM Vehicle Thermal Systems engineer. "The testing we perform on the Chevrolet Cruze with the diaper material allows us to maximize the car's heating capabilities." Ironically, Jahn stumbled upon his diaper-based testing method in the middle of summer. During a swim with his daughter, he noticed her diaper multiplied in size when it came into contact with water.