2008 Chevrolet Cobalt Sport Coupe on 2040-cars

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GM will recall 3.5 million pickups and SUVs to fix brake issue

WASHINGTON — General Motors Co is recalling 3.46 million U.S. pickup trucks and SUVs to address a vacuum pump issue that could make braking more difficult and increase the risk of a crash. The recall, which covers 2014-2018 model year vehicles, including some Cadillac Escalade, Chevrolet Silverado, Chevrolet Tahoe, GMC Sierra, Chevrolet Suburban and GMC Yukon vehicles, was triggered because the amount of vacuum created by the vacuum pump may decrease over time, GM told the National Highway Traffic Safety Administration (NHTSA) in documents posted Wednesday. NHTSA opened a preliminary investigation into the issue in November 2018, and said it had reports of 9 crashes and two injuries related to the issue. It provided GM in July with additional field reports that prompted the automaker to open an investigation. The company did not immediately say on Wednesday how many injuries or crashes are linked to the issue but said it could impact braking in "rare circumstances." GM said dealers will reprogram the Electronic Brake Control Module with a new calibration that will improve how the system utilizes the hydraulic brake boost assist function when vacuum assist is depleted. GM said the vacuum assist pump, which is lubricated with engine oil that flows into the pump through a filter screen, can in some cases lose effectiveness over time, as debris such as oil sludge can accumulate on the filter screen. GM told NHTSA that prior model years used a different brake assist system design, and vehicles manufactured after 2018 were not equipped with the affected pump design. Recalls Chevrolet GM GMC

'Killing a Duramax' Gale Banks YouTube series methodically tunes a diesel to death

Learning or perfecting a skill by watching YouTube videos is known as attending YouTube University. GM Authority picked up on one of the video site's more fascinating courses, hosted by Gale Banks; in a fair world, he should be referred to as Professor Banks when it comes to diesel engines and truck tuning. A few months after GM introduced the updated L5P 6.6-liter Duramax diesel V8 in the 2020 Chevrolet Silverado HD and GMC Sierra HD that ships with 454 horsepower and 910 pound-feet of torque, Banks decided he wanted to methodically tune the engine to death. The purpose of the resulting series, called "Killing a Duramax," is to push more power out of the engine in order to discover which parts break and when — or, as Banks puts it, force-feed the Duramax "until the crank hits the street and the heads hit the hood." With that knowledge, Banks can figure out all the weak points on his way to building what he calls a "Superturbo," that being a supercharged, twin-turbo race engine with more than 1,000 hp. What makes the series fascinating is Banks' knowledge, paired with the company's comprehensive iDash engine monitoring system that keeps tabs on a glut of parameters every step of the way. So for instance, you get Banks explaining the differences between inches of mercury and barometric pressure, how those are different from the water content of the air measured in grains, then showing those readouts on the iDash, then explaining in detail how they affect the air density in the Duramax system. The stock Borg-Warner variable turbo gets a lot of airtime — Banks accuses it of being "out to lunch" because he feels it's the weakest link on the engine. That turns into a turbo teardown and a deep explanation of performance pitfalls, such as when air pressure on the turbine begins to diverge from the boost pressure coming from the compressor. Banks says he can keep close tabs on where power's coming from, because the iDash monitors the horsepower contribution provided by the ambient air, the turbo, and the intercooler separately. The major changes so far are a stouter Precision 7675 turbo and TurboSmart wastegate (episode 5), a twin intake (episode 6), a custom liquid-cooled intercooler from a marine engine, a new GM oil cooler and synthetic oil (episode 10), and new injectors (episode 11).

Chevrolet Colorado ZR2 concept suggests a diesel off-road future

"It takes the Colorado to a whole new place." – Mark Reuss The Chevrolet Colorado looks set to gain a more capable off-road version, with the company previewing a potential design direction with a ruggedized concept Wednesday at the Los Angeles Auto Show. Called the Colorado ZR2, the concept brings back the name used on off-road-tuned S-10 and Blazer models in the 1990s and 2000s. The ZR2 has a track that's four inches wider than the Colorado Z71, which is currently the line's most capable off-roader. The ZR2 is fitted with a new grille, power-dome hood, custom wheel flares and off-road-style fascia that reduces overhang and has flip-out aluminum tow hooks. It's all slathered in an outdoorsy hue dubbed Cyprus Green. The are electronic locking front and rear differentials, skid plates and mono-tube coilover shock absorbers. It all rolls (or crawls) on 275/65R18 off-road tires wrapped around custom 18-inch aluminum wheels. There's also a spare tire assembly mounted in the bed, which has a spray-in liner and 48-inch lift jack should things go afoul on the trail. "It takes the Colorado to a whole new place," Mark Reuss, General Motors executive vice president of global product development, said at the reveal. Power comes from the 2.8-liter Duramax diesel engine making 181 horsepower and 369 pound-feet of torque. This engine will arrive later in the year in the production Colorado. While the ZR2 remains only a concept, it suggests a new path for the Colorado – one we hope Chevy decides to take. Chevrolet Introduces Colorado ZR2 Concept Aggressively styled, more capable and driven by new 2.8L Duramax diesel engine LOS ANGELES – Chevrolet today introduced the Colorado ZR2 concept – a vision of how Chevrolet could take the all-new midsize truck's off-road capability to the next level. It also showcases the new 2.8L Duramax diesel engine that will arrive in the Colorado lineup later next year. The aggressively styled concept builds on the capabilities of the production Colorado Z71 and advances the legacy of Chevrolet's previous ZR2 production models. "From the bold stance to the trail-ready special equipment, the Colorado ZR2 is all about the fun of driving where the pavement ends – and doing it in characteristic Chevy style," said Tony Johnson, Colorado marketing manager.