- We took shipping of a very long-expression Cadillac CT5-V Blackwing in March 2022.
- Right after respecting the 1500-mile crack-in period, we strike the monitor for preliminary functionality testing.
- Immediately after about 15 standing-start out launches, the LT4 V-8 begun misfiring seriously.
Our elation soon after having shipping of a 2022 Cadillac CT5-V Blackwing for a 40,000-mile extensive-term check immediately turned to despair just after its 668-hp supercharged V-8 experienced a catastrophic engine failure in the course of our original examination session. After respecting the 1500-mile break-in period—keeping the revs under 4000 rpm and not sitting down at a frequent speed for prolonged periods—we hit the examination monitor with just more than 1800 miles on the odometer to log its original efficiency figures.
We took our time participating in with the Blackwing’s extremely adjustable start-regulate characteristic that lets the driver to find separate launch-rpm and slip-concentrate on configurations, and then tried using a few unassisted dances on the pedals with our ham hocks to see if we could defeat it (we could). Following about 15 launches, we have been pretty much ready to contact it when disaster struck. Although coasting to the much stop of the straightaway following a operate, a host of warning messages popped up on the gauge cluster, all tied to a critical misfire.
The LT4’s even cylinder financial institution in which all the hurt occured.
What occurred? That’s a superior dilemma, one that was not answered conclusively even next a finish teardown at GM’s powertrain headquarters in Pontiac, Michigan, wherever the engine went immediately after it was eradicated by our area Cadillac supplier. The damage was restricted to the even-numbered cylinder financial institution, with cylinder six using the brunt of the carnage its cylinder partitions had been scored, and aluminum plucked away from the edge of the piston and sprayed on top rated of it as nicely as on the exhaust valve. The critical temperature and strain also blew off the floor strap at the finish of the spark plug, and even the solid-iron cylinder liner showed some pitting.
Terrible gas could have caused this variety of pre-ignition or knocking, but then both banking companies would have been influenced. So compact-block assistant chief engineer Mike Kociba thinks it was likely one particular of two items that took place: Possibly the gas offer on that aspect of the rail was somehow depleted—a contaminant restricting the movement somewhere—or a related blockage in the cooling program that allowed items to get too incredibly hot. But, through the teardown, they did not find this sort of a blockage in possibly process.
Kociba assured us it had nothing at all to do with the severity of our use, and that the engine can happily do standing-start off launches all day. Furthermore, he stated that of the approximately 20,000 supercharged LT4 variants of the Gen V small-block V-8 the organization has marketed to date—in the C7 Corvette Z06, Cadillac CTS-V, Camaro ZL1, and now the CT5-V Blackwing and Escalade V—ours is the 1st and only these kinds of failure.
Nonetheless, this is not the 1st time a Gen V compact block permit go in our palms. The normally aspirated LT1 V-8 in our very long-term 2014 Corvette essential to be replaced right after a connecting-rod bearing failed, most likely due to a metallic burr that originated from the block or oil-filter threads.
With our CT5, it took about 6 weeks for our local seller to eliminate the motor, get a new a single from GM, and install it. And then, of training course, we had to just take it easy the moment all over again in the course of a next break-in period.
Then we again strike the take a look at track for significantly tough functioning, and this time it took it in stride, clocking a dash to 60 mph in 3.7 seconds and 11.7 seconds via the quarter-mile at 124 mph, and shrugging off recurring operates. Just as we’d expect from one particular of the fiercest-ever sports sedans.