6.2 Crankshaft Bearings from TechLink

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V8 Engine Crankshaft Bearing Conditions

March 24, 2023
A no crank condition may be found on some 2019-2023 Silverado, Sierra; 2021-2023 Tahoe, Suburban, Yukon and Escalade models equipped with the 6.2L V8 engine (RPO L87). The no crank condition may be due to a seized engine with an open starter fuse. Various engine sounds, such as a thumping, knocking or rattling, may be present. These conditions may be the result of crankshaft bearing failure. (Fig. 5)


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Fig. 5

In cases involving suspected bearing failure, first check the engine oil and filter for excessive metal debris and bearing material. (Fig. 6) Inspecting the oil filter for excessive debris and damaged pleats can be a helpful indicator of the amount of material that has been displaced through the engine and lubrication circuits.



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Fig. 6


If bearing material is identified, remove the engine oil pan and inspect the crankshaft rod and main bearings for any damage. Component replacement or, depending on the extent of damage, engine replacement may be necessary.
Engine Component Replacement Guidelines
The amount of bearing damage determines if the engine should be replaced. Bulletin #18-NA-073: Repair Guidelines for Engine Component Wear provides details about wear characteristics of engine components and replacing worn components, including the crankshaft main bearings and journals. Engine assembly replacement should be based on the extent of the damage to individual components. (Fig. 7)


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Fig. 7


Oil Cooler Components
If there is crankshaft main bearing failure, it may be necessary to also replace the oil cooler, oil cooler lines and oil tank, if equipped, along with the damaged engine components. Refer to Bulletin #22-NA-074 for more information about engine repairs after crankshaft main bearing damage.
If the main bearing debris is sent through the oil galleries and other components that are in the lubrication circuit, which are very difficult to completely clean, it could lead to additional damage when installed on a new engine. When there is extensive damage, oil cooler, oil cooler line and oil tank replacement ensures all debris is completely removed and that any bearing failure debris is not transferred into the new service engine.
For additional information, refer to #PIP5900.
 
Well that's scary! I haven't seen any metallic in my oil when I've changed it and I'm at just over 14K now. Another reason to do your own maintenance! I doubt a dealership oil change bay or especially a quick oil change place would even look at the old oil. They're just in a hurry to get you out of there and on to the next customer.
 
I got new engine at 9000 miles for scored main bearings. It was a weird sound, engine didn’t make it at idle, only under slight load. Service adviser couldn’t hear it but the lead tech heard it. Took them about a week to isolate.

All new engine, oil cooler, oil lines. Never heard a final reason but one tech hinted at some debris during engine assembly.

No issues since but….
 
I would assume that any debris in the oil would get circulated throughout the entirety of the engine, to include lifters, rockers, ring land orifices, etc. I would STRONGLY argue for a new motor if any oil is found to have metallic contaminants, regardless of percent or size. Its circulated throughout the entire engine assembly causing additional damage to who knows how many bearing surfaces and potentially clogging oil pathways and components.
 
My 6.2 engine went out a few weeks ago due to this at ~21k miles. They are replacing the entire engine under warranty since it is a 2022 model. I've definitely lost trust in the vehicle and not sure now whether to keep it or not - but loosing ~30k+ selling it after 18 months feels awful.
 
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