2003 Chevy Duramax 4x4 Ext. Cab Allison on 2040-cars

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2016 Chevrolet Colorado Diesel First Drive [w/video]

The first thing you notice inside the diesel Chevy Colorado is that it's quiet. Almost too quiet. A lot has been done to quell noise and vibration with this new powertrain, and it shows – or rather, doesn't. There's some characteristic diesel clatter at idle, but even then it's distant and practically disappears as you start moving down the road. At full throttle, when the engine is at its noisiest, the sound isn't particularly diesel-like, just a pleasant intake breath. The accompanying smoothness is almost eerie. When we ask where all the noise went, Chevy's engineers, marketing guys, and PR reps all explain that this refinement is what Americans want. We're still not sure. This is a truck, after all, and the diesel pickup customer is different from the guy buying a diesel Cruze for his highway commute. Chevy contends that they're also not the same as the buyer of a Silverado HD. Although this 2.8-liter Duramax four-cylinder has been in service elsewhere around the globe, its first US application is in the Colorado and its GMC Canyon twin. The engine puts out 181 horsepower and 369 pound-feet of torque, and it does so unobtrusively as a result of a lot of modifications for our market. To keep normal diesel sensations out of the cabin, the intake and oil pan both get acoustic treatments. A new, thicker material is used for firewall sound deadening. Redesigned balance shafts have tighter tolerances to increase smoothness. The diesel powertrain is smoother than the Colorado's gasoline V6. One of the more interesting and certainly unexpected vibration-reduction changes is a special torque converter from German supplier LuK equipped with a centrifugal pendulum absorber. This pendulum spreads from the center of the torque converter as engine speed increases and is tuned to absorb the four-cylinder's second-order vibrations, not just those in a narrow frequency band. It does an admirable job, especially considering the engine's biggish, 0.7-liter cylinders, which lead to bigger vibrations. The result is a powertrain that's smoother than GM's (not particularly smooth) corporate V6, which is available in the standard Colorado. It's quieter than a Cruze diesel and even out-softens some gas direct-injection engines on the market. Paradoxically, it may be the most refined of all of the Colorados. No vibration comes through the steering wheel, pedals, floorboards, or even the rearview mirror. But you can tell it's a diesel when you hit the throttle.

Some 2012-13 Chevy Volts may not have enough battery coolant

The 2012 and 2013 model year Chevrolet Volt extended-range plug-in vehicle may have a battery glitch caused by low coolant levels. No recall has been issued and General Motors is taking care of the issue at no cost to drivers. Some of the affected Volts may have lower-than-advisable coolant levels because of some pesky air pockets in the car's cooling circuit. When the coolant levels get too low, the charging system for the battery powering the car's onboard generator (i.e. the Rechargeable Energy Storage System, or the RESS) may be shut down, turning one's Volt into a run-of-the-mill gas-powered car, and a pricey one at that. The Car Connection says GM is advising owners of the '12 and '13 Volts to contact their local Chevy dealer for a free fix. GM representatives didn't immediately respond to a request for comment from AutoblogGreen for more details. We believe this is a separate issue than the one that brought 8,000 Volts back to the dealers for a battery coolant fix, what GM called a "voluntary customer satisfaction effort," a few years ago. General Motors sold 23,094 Chevy Volts last year after selling 23,461 Volts in 2012, so that fix-it list may get fairly lengthy. Check out a GM-Volt.com user thread related to this issue here. *UPDATE: Chevrolet spokesman Randy Fox confirmed in an e-mail to AutoblogGreen that the company issued a service bulletin to dealers that they may need to top off coolant levels on certain Volts because of the issue, and that the vehicle will "return to normal charging operation" once that's done.

Chevy keeps teasing next Camaro, 70 percent of parts unique to it [w/video]