1994 Gmc G3500 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.

GM under fire from safety advocates over braking problem caused by recall fix

Safety experts are lambasting General Motors over what they say is the automaker’s slow notification of owners of certain 2019 sedans and trucks that a recall fix could cause power braking to fail and increase the risk of a crash, the Detroit Free Press reports.  GMÂ’s original recall in December targeted about 550,000 Cadillac CT6 sedans and Chevrolet Silverado 1500 and GMC Sierra 1500 pickups, all from the 2019 model year, over potentially defective electronic stability control and antilock brakes. In that case, GM said the errors would not show up as a diagnostic warning on the instrument cluster. But after GM had done recall work on 162,000 vehicles, about 1,700 owner have complained that their power brakes didnÂ’t work after they had the recall done and then used the OnStar app to start their vehicle. GM then issued a supplemental fix for customers whoÂ’d already had their vehicles serviced. In this case, a diagnostic warning should illuminate saying either “Service Brake Assist” or “Service ECS,” which GM says is a signal that a customer should not drive the vehicle and instead call their dealer, which will tow the vehicle and have it repaired. Safety advocates say the automaker hasnÂ’t gone far enough to protect customers. “The fact that you could potentially start a vehicle and not have brakes is a pretty risky proposition,” Sean Kane, president of the Safety Research and Strategies, which works on auto issues for plaintiffs and governmental organizations, told the Freep. “The fact that they wouldnÂ’t notify owners (sooner) is pretty stunning.” GM told the Freep it was required to notify the National Highway Traffic Safety Administration and file paperwork before it notified customers about the original recall, which was made Dec. 12. It then had to investigate and resolve the problem created by its original recall fix before alerting customers. GMÂ’s call center and dealers are contacting the remaining 900 customers who havenÂ’t yet had the update made to the original recall repair. GM also hired a vendor to send recall letters to the 550,000 customers affected by the original recall notifying them about the update. There are no known injuries or deaths related to the problem. Read the Freep story here.

GM SUV window switch recall urges owners to park vehicles outside

It's not unusual for there to be a lag between an automaker announcing a recall and the official documentation showing up on the National Highway Traffic Safety Administration website. So it's no surprise that a recent GM campaign took about a month to appear in its official capacity. However, there appears to be some big differences between the two reports with potential safety implications.
In late June, GM announced that it needed to recall 181,984 examples of the Chevrolet Trailblazer, Buick Rainier, GMC Envoy, Isuzu Ascender and Saab 9-7x from the 2005-2007 model years, plus the 2006 Chevy Trailblazer EXT and 2006 GMC Envoy XL. The new documents paint a slightly different picture with 184,611 needing repaired and different model years listed.
The reason for the fix is still the same, though. It's possible for fluid to contact the master power window switch module in the driver's door, which can corrode the part. Eventually this could cause a short circuit, leaving the buttons inoperable and potentially leading to a fire. But the new NHTSA documents add an important note: "A fire could occur even while the vehicle is not in use. As a precaution, owners are advised to park outside until the remedy has been made."