2003 Gmc Yukon Xl 1500 Denali Sport Utility 4-door 6.0l on 2040-cars

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Chevy's 6.6-liter Duramax is pretty much all new

To say there's a heated battle in heavy-duty pickups is an understatement, with Chevrolet, Ford, and Ram constantly trading blows of increased torque, horsepower, and towing capacity. The latest salvo is the revised, more powerful turbo diesel 6.6-liter Duramax V8 in the 2017 Chevy Silverado. It has 910 pound-feet of torque, an increase of 145, putting it nearly level with the Ford Super Duty. Here's a closer look at where those gains come from. How exactly did Chevrolet add all that torque plus 48 horsepower? The automaker essentially took a fine-tooth comb to the entire engine. Chevy says it changed 90 percent of the V8, and the cumulative effect of those small changes adds up to big increases. As you might guess, the turbocharger is updated. The larger unit features electric actuation of the variable nozzle turbine (VNT), and what Chevy calls a double axle cartridge mechanism that separates the VNT moving parts from the housing. That helps with heat performance as well, with a claim that the exhaust side of the turbo can run continuously up to 1,436 degrees Fahrenheit. Helping that cause are six exhaust gaskets made of Inconel - an nickel alloy that contains chromium and iron – and upgraded stainless steel for the exhaust manifold. Despite having the same cast iron cylinder block, albeit with some minor enhancements, the engine has new cylinder heads, pistons, piston pins, connecting rods, and crankshaft, which have all been upgraded to handle 20 percent higher cylinder pressures. Alongside the increase in pressure, Chevrolet also increased the cylinder head's structure with a honeycomb design. The pattern features high-strength aluminum with dual layer water jackets that not only improve strength, but also optimize water flow for better cooling. For 2017, the cylinder head also benefits from integrated plenum that aids the engine in getting more air under heavy loads. The cylinder head isn't the only component to get a minor update, as the pistons have a larger diameter pin for improved oil flow. The same detailed improvements has been bestowed to the humble connecting rods (second in our hearts only to the inanimate carbon rod). The new design has the bolts oriented roughly 45-degrees to the rod instead of parallel. The angle split design, as it's called allows for easier passage through the cylinder.

2014 Chevrolet Silverado and GMC Sierra debut all-new designs, three new engines

General Motors has finally dropped the curtain on the 2014 Chevrolet Silverado and 2014 GMC Sierra. Both trucks have undergone substantial revisions with updated versions of the company's 4.3-liter V6, 5.3-liter V8 and 6.2-liter V8 engines. In a shot across the bows of both Ford and Chrysler, GM says it won't use a V6 engine adapted from passenger car applications. Instead, it developed the 4.3-liter engine based on its proven truck-duty architecture.
All three mills will boast direct injection fuel systems as well as a new cylinder head design. Combined with a revised piston, the new engines feature a smaller combustion chamber with a compression ratio of 11:1 or higher depending on the application. Cylinder deactivation and continuously variable valve timing are all part of the recipe, and each engine is paired with a six-speed automatic transmission with auto grade breaking. So far, no fuel economy or horsepower figures have been released, though GM says the new engines will best their predecessors in both areas.
Outside, the trucks feature a number of enhancements to reduce drag and wind noise, and GM claims both the Silverado and Sierra will offer buyers some of the quietest cabins in the class. Extended cab models now feature front-hinged rear doors to allow easier access to the back passenger area, and Crew Cab buyers can now select between a five-foot, eight-inch bed or a six-foot, six-inch bed. Buyers with a mind toward going off road will also rejoice in the return of the Z71 package, complete with Rancho shocks, front tow hooks and additional under-body protection.

GM recalls 83,572 SUVs for ignition switch issue

General Motors is recalling 83,572 SUVs from the 2011 and 2012 model years over a potential ignition lock actuator issue. In affected vehicles, the actuator isn't the right size, which could cause the ignition to get stuck in the "Start" position, and then either due to a jarring event or a "cool interior temperature" the ignition could switch back to the "Accessory" position. Doing so would cause a loss of power assistance and the airbags might not deploy. This is a different ignition issue than the one that's been ongoing for the past year. GM said it expects that less than 500 vehicles suffer from the problem, but that the pool could include vehicles from 2007 through to 2014 that have already been fixed, but with defective parts. The 2011-2012 SUVs included in the National Highway Traffic Safety Administration notice: Cadillac Escalade, Escalade ESV, Escalade EXT, Chevrolet Avalanche, Silverado HD, Silverado LD, Suburban, Tahoe, GMC Sierra LD, Sierra HD, Yukon, and Yukon XL vehicles. GM will notify owners and dealers will inspect the ignition lock housing to see if it needs a free replacement. RECALL Subject : Ignition Lock Actuator may Bind Report Receipt Date: DEC 30, 2014 NHTSA Campaign Number: 14V827000 Component(s): ELECTRICAL SYSTEM Manufacturer: General Motors LLC SUMMARY: General Motors LLC (GM) is recalling certain model year 2011-2012 Cadillac Escalade, Escalade ESV, Escalade EXT, Chevrolet Avalanche, Silverado HD, Silverado LD, Suburban, Tahoe, GMC Sierra LD, Sierra HD, Yukon, and Yukon XL vehicles. In the affected vehicles, the ignition lock actuator may bind, making turning the key difficult or causing the ignition to get stuck in the "Start" position. CONSEQUENCE: If stuck in the "Start" position, the ignition may suddenly snap back into the "Accessory" position, causing a loss of engine, steering, and braking power, increasing the risk of a vehicle crash. If the vehicle is in a crash, the air bags may not deploy, increasing the risk of occupant injury. REMEDY: GM will notify owners, and dealers will inspect and replace the ignition lock housing, as necessary, free of charge. The manufacturer has not yet provided a notification schedule. Owners may contact GM customer service at 1-800-458-8006 (Cadillac), 1-800-222-1020 (Chevrolet), or 1-800-462-8782 (GMC). GM's number for this recall is 14696 for the original equipment, and 14912 for the service replacement parts.