Home, Library, Auto Parts, Accessories, Tools & Eqpt, Books, Car BLOG, Links, Index

GM 6.2L L87 V8 Engine Failures & Recall

General Motors recently announced a major recall of over 700,000 fullsize GM trucks and SUVs equipped with the 6.2L L87 V8 due to possible premature engine failure.

The recall notice is N252494001L87 Engine Loss of Propultion, issued April 2025

The recall affects 2021 through 2024 model-year Cadillac Escalade, Chevrolet Silverado 1500, Suburban, and Tahoe, GMC Sierra 1500, Yukon, and Yukon XL.

GM is blaming the recall on possible manufacturing defects in the connecting rod bearings that may cause the bearings to seize and lock up the engine and/or break the connecting rod and damage the engine block.

So what exactly is causing these engine to fail?

The Real CauseBeahind the GM 6.2L L87 Engine Failures

Yes, it is possible that some of these engines were asembled with bearings that did not meet specifications (too hard, too soft, incorrect dimensions), that the assembled bearing clearances were incorrect (too tight or too loose), or that machining debris if the engine block or cranksaft oil delivery holes was not cleaned prior to assembly. But from what I've seen, the REAL PROBLEM appears to be the viscosity of the oil GM chose to use in these engines.

The factory fill oil for the 6.2L V8 engine is 0W-20. This is a very thin low viscosity motor oil designed to meet CAFE fuel economy standards. It's good for maybe a few tenths of a mile-per-gallon improvement in fuel economy. The oil specified for this engine must also meets GM's "dexos" performance specifications

Dexos is an advanced full synthetic motor oil with an enhanced additive package designed to reduce friction, improve wear resistance and resist heat oxidation. The first version of dexos was introduced in 2010. It was formulated to pass a series of 11 tests that meet or exceed ILSAC GF-4 and GF-5 industry specifications.

In 2015, dexos was reformulated (dexos 1 gen 2) to better resist a problem called "low speed pre-ignition" which can occur in late model engines with Direct Gasoline Injection. Oil residue in the combustion chamber can ignite before the spark plug fires, essentially causing a misfire condition that reduces power and may damage the engine.

In 2021, GM tweaked the dexos additive package yet again (dexos 1 gen 3) to improve sludge resistance in late model engines with cylinder deactivation and/or hybrids with fuel saving idle stop-start systems. And this is what ended up in the 2021 and newer 6.2L engines.

So is dexos 0W-20 gen 3 motor oil a poor choice for these engines? Probably. Here's why.

Ultra Thin Motor Oils Not Good for Engine Bearing Longivity

Really thin oils like 0W-20 flow much more easily than thicker viscosity oils when an engine is cold for easier starting, especially in cold weather. A thinner oil also allows oil pressure to build more quickly than a thicker oil, improving lubrication to the upper valvetrain components. And loer viscosity oils also reduce friction for better fuel economy. But there are some drawbacks, too.

Thinner oils require closer main and rod bearing clearances to maintain adequarte oil pressure in the engine. If bearing clearances are too loose, the oil may leak out of the gap between the bearing surfaces and crankshaft journals. Under high loads, this may lead to a loss of the protective oil film allowing metal-to-metal contact which can result in bearing overheating, scuffing, damage and even seizure (a so-called "spun bearing"). If a rod bearing seizes, it may lock up the engine or it may cause the connecting rod to break. A broken rod swinging around inside the crankcase canknock a hole in the side of the block, destroying the engine.

Engine Damage Resulting From Loss of Lubrication

The following photos show the kind of damage that can occur when the oil is too thin, or is diluted with too much moisture, unburned fuel or other contaminants (usually as a result of not changnt the oil often enough to keep it clean).

These badly scuffed and discolored bearings are the result of poor lubrication.

This rod bearing shows the kind of scuffing that can occur where there is not enough oil between the bearing and crank.

Heat discoloration of the connecting rod caps is a sure sign of poor lubrication and overheating in the bearings.

With the rod journal cap removed, you can see how the crankshaft journal has been damaged.

The bearing on this connecting rod has seized the crank journal and spun (rotated) from its normal position. This can seize the engine and often break the connecting rod.

GM's Recall Fix for the 6.2L L87 V8 Engine Failure Problem

GM is telling its dealers to first check the customer's vehicle for a code P0016. This is a diagnostic trouble code that indicates a possible timing misalignment between the camshaft and crankshaft. If the engine has this code, they are advised NOT to do the next step but to replace the engine.

Any number of things can cause a mechanical timing error in an engine, including a stretched or broken timing chain, a bad crankshaft or camshaft position sensor, a bad crankshaft or camshaft reluctor wheel, or even a broken camshaft or crankshaft. None of these have anything to do with the bearing lubrication issues that are causing the engine failures people are experiencing. It is an entirely different problem, one which may result in a totally different recall if it turns out GM is having engine timing failures too.

The "fix" GM is recommending (assuming the engine does not have a mechanical timing issue), is to simply drain the 0W-20 oil from the engine and refill the crankcase with a 0W-40 oil that meets dexos gen 3 specifications.

NOTE: ANY brand of 0W-20 motor oil can be used for the refill provided it meets the dexos gen 3 specifications. Most major brand synthetic motor oils are formulated to meet or exceed the dexos gen 3 specifications, but some store brand/generic motor oils may not. So my advice is to stick with a well-known quality brand of oil and don't buy the cheapest oil on the bottom shelf at Walmart.

GM also tells its dealers to replace the oill filler cap with one that is marked to indicate the new required oil is 0W-40, not 0W-20, and to also replace the oil filter. An AC brand filter is recommended by GM, but again any brand of quality oil filter will do.

Personally, I don't like 0W motor oils in any truck engine or turbocharged engines. I think 0W oils are too thin, especially in hard working applications if the oil is not changed often enough to maintain the additive package and to get rid of the crankcase contaminants that accumulate and dilute the oil (moisture & unburned fuel).

I prefer 5W-20 or 5W-30 motor oil because the cold viscosity is a little thicker and provides better protection. GM's recommendation of upgradoing to 0W-40 for the 6.2L V8 provides better hot weather protection, but for cold starts it may still be a little too thin. A 5W-40 motor oil would be even better, in my opinion, but I don't think anybody makes a 5W-40 oil that meets the dexos gen 3 specs.

I would NOT recommend using a 15W-40 oil in a late model 6.2L L87 because of the cylinder deactivation system.

The hydraulic valve lifters use oil pressure to control valve operation. Solenoids control oil flow to the lifters. When cylinder deactivation occurs while cruising under light load, the solenoids block the flow of oil to some of the lifters. This causes the lifters to collapse and stop opening the valves. The engine runs on fewer cylinders and uses less fuel. When oil pressure is restored, the lifters pump up and start opening the valves again, restoring full engine power.

If the oil in the engine is too thick (say 15W-40), it will not flow as easily or quickly into the lifters, which may delay reactivating disabled cylinders. This could cause a momentary loss of power, hesitation or stumble when full power is needed.

A 15W-40 oil may also be too thick to flow easily between the rod & main bearings and crankshaft in the 6.2L V8. The internal bearing clearances in these engines are relatively tight to maintain oil pressure with the factory fill 0W-20 motor oil. If you switch to a significantly thicker oil like 15W-40, the bearings may not receive enough lubrication causing them to fail.

If you want to run 15W-40 oil in a 6.2L L87, I would recommend replacing the main and rod bearings with ones that have an extra .001 inches of clearance to compensate the thicker oil. Choosing a high performance coated bearing would provide extra insurance against future bearing failure.

Change The Oil More Often

Another word of advice I would offer on these engine is to change the oil more often. The factory recommended interval of 7500 miles (which may stretch to as much as 15,000 miles if you are relying on the Oil Life Reminder indicator) is not often enough, especially if you do a lot of short trip driving during cold weather, or do a lot of heavy towing. My recommendation is to change the oil every 5,000 miles, and to always use a top quality brand name synthetic motor oil that meets the dexos gen 3 specifications. Don't use anything else, and don't trust a Quick Lube shop to use the correct oil. Quick Lube shops have a bad history for using substandard bulk motor oils that often fail to meet either the viscosity or performance requirements for today's engines.