BREAKING: GM is officially recalling the L87

[WalleyeMikeIII]

https://static.nhtsa.gov/odi/rcl/2025/RCRIT-25V274-2909.pdf

Updated parts list for 002 bulletin published today.

 

[Antonm]

I believe the oil pumps are variable pumps that control oil flow when needed.

How oil pump works on new 6.2 gm engines - Bing

Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you.

www.bing.com

https://gmauthority.com/blog/2025/05/should-you-use-0w-40-oil-in-your-non-recalled-gm-6-2l-l87-engine/

They can vary between two flowrates, a high and a low, via a bypass solenoid. The pump itself is fixed displacement.

If you look at the pictures in your link you can see these are gear style positive displacement pumps and they are directly driven off the crankshaft.

The pump spins one revolution, the same volume of oil is pumped regardless of its viscosity.

Part of one potential "solution" that was investigated was to just command the solenoid to stay in the full flow/ high flow/ normal/ non-bypass position all the time, and GM may still choose to do that with a future software update.

While positive displacement pumps do move the same volume per revolution regardless of fluid viscosity , the power input does go up if you use a thicker fluid (hence the slight fuel milage reduction because the parasitic drag is more).
...

 

[jfoj]

I believe the oil pumps are variable pumps that control oil flow when needed.

How oil pump works on new 6.2 gm engines - Bing

Intelligent search from Bing makes it easier to quickly find what you’re looking for and rewards you.

www.bing.com

https://gmauthority.com/blog/2025/05/should-you-use-0w-40-oil-in-your-non-recalled-gm-6-2l-l87-engine/

The oil pumps are variable displacement pumps the have a spring along with oil pressure to modulate the oil volume to create a specific oil pressure. They are vane style oil pumps similar to the automatic transmission oil pumps. The ONLY Software/Firmware involved with the 2 stage oil pumps (NOTE 2 STAGE OIL PUMPS ARE VARIABLE DISPLACMENT OIL PUMP WITH A SOLENOID THAT WILL TRIGGER THE OIL PUMP TO PRETTY MUCH DOUBLE ITS PRESSURE)

I have watched and logged the 2 stage pump both in self testing on start up as well as when the second stage is triggered typically based on engine RPM, because I have NOT seen the 2nd stage triggered under HIGH (80-100%) loading at lower RPMs.

I can tell you this much there is little to no difference in the oil pressure between 0W20 and 0W40. I have seen around 35 PSI at idle and 45 PSI while cruising at highway speed and the engine RPM around 1500-1700.

Everyone can opine on how bad 0W40 or 5W30 is. It is NOT a problem. Even the General is telling everyone to change to 0W40 for engines that were "speced" for 0W20. Other GM V8 of similar vintage were also speced for either 5W30 or 0W40.

There are countless posts of people running higher viscosity oil in these V8's with no negative impact and one common comment is that the engines will tend to operate overall quieter, less mechanical chatter.

I just ran my truck 750 miles over 14 hours in 2 days with 0W40, will be running another 600 miles in the next 2 days. As for how much cooler the engine oil is with 0W20 vs 0W40, I do not have good 0W20 temperature data because I kicked it to the curb at 544 miles, but I was watching the 0W40 oil temps after driving for almost 5 hours and averaged around the 210F mark and at times varied based on engine loading to probably between 206F and 216F. I did not have full logging enabled, I was casually monitoring the oil and coolant temps in real time.

I will say is again and again, while 0W20 will work for these V8's there is little safety margin once the oil becomes fuel diluted. Driving conditions and ambient temperatures play into this a lot as well as Oil Change Intervals. I can tell you from the extreme loading the 6.2l is under at low RPM on normal highway driving pulling even a slight grade, I am not going to run 0W20 oil in my engine.

Everyone has an opinion, do what you feel is right, but I have pulled a lot of data and I do not like gambling on 0W20 for someone's idea of making a specific fuel economy requirement with the way the 6.2l is tuned and operated in the later model trucks. I did not by this vehicle for fuel economy, I bought it to haul people and cargo.

 

[jfoj]

To recap for me, I’m a bit lost. All 21-24 6.2. the end of the run being engine build date 24165, about July 1, 2024. In this group you will be inspected for the p16 code. If code is present you get new motor and keep 0-20 oil. if no code you change to 0-40 oil and get power train extension to 10yr/150k. If outside this group 2020 or post 24166 and 2025 and you stay with 0-20 oil. Am I close?

This entire mess is a moving target, I really think GM is back peddling trying to get out of wholesale engine replacements and I think they will be somewhat successful.

They originally did not offer any warranty extension, now I am hearing info that GM may be working on a vacuum test to verify bearing clearances similar to what Kia had to go through. This way they may reduce the number of engines that are expected to replace.

BUT the vacuum test cannot really determine if the main bearings are scoured or damaged and I doubt it can determine main bearing clearances. Thrust beating clearance can be easily checked and some engines had thrust bearing failures.

My guess is there will be a large group of engines that will be sent out after "inspection" with 0W40 oil and the 10 year/150,000 mile engine warranty from the vehicle IN SERVICE DATE!

We shall see, this will not be fully decided until July IMHO.

 

[Blackcar]

Yea that's all fine but if your out of warranty I don't want to be stung buying new engine so watching situation develop.

 

[jfoj]

I have a 2024 that was built in July 2023. I scanned it myself for P0016 and it was clear. I already changed to 0W-40. What I don’t see is any recalls for my VIN. This makes no sense because my build was definitely before the June 1st 2024 cutoff. I want to at least get a call so I can grab my new oil cap and extend from 5/60,000 to 10/150,000 on my PWT Warranty.

You sure you 2024 was built in July 2023?? The typical model year change over starts in Sept. I think if you have a 2024 it was likely built in July 2024, which is on the edge.

First the discussion indicated any engine built on or after June 1, 2024 was fine, then they moved to July 1, 2024. If you have a July 2024 build, you MIGHT be outside of the July 1, 2024 engine build date. You would need to check the engine tag on the back of the driver side cylinder head for the Juilian Build Date.

My 2024 was built in 8/2024 and has an engine build date of July 15, 2024.

 

[the 18th letter]

WTF are the CAFE requirements that everyone is talking about that can only be met using 0-20 oil. Does using 0-40 or 5-30 screw up your MPG’s that badly while providing extra protection?

 

[viven44]

@Vladimir2306 @Antonm @jfoj you guys should seriously find a parking lot and discuss oil viscosities

Personally, I don't think even GM knows what's best

 

[PPV_2018]

@Vladimir2306 @Antonm @jfoj you guys should seriously find a parking lot and discuss oil viscosities

If this becomes reality i’m taking bets

 

[jfoj]

Vehicles are certified for EPA MPG and Emissions under specific conditions. Change the oil viscosity and you have a new set of variables and in theory you no longer are "certified" by the EPA.

While I have no idea what the my 2024 Yukon Denali XL fuel economy would have been 100% stock, it is rated at 18 MPG on the Highway.

I just did a 750 mile run and at least the dash indicated I was able to achieve 20.8 MPG. This was not 100% highway, but did have some in town and stops on the State Routes. I was driving mostly State Routes and only a portion Interstate. 354 Miles, 20.8 MPG, Average speed 61 MPH.

Understand I am running 0W40 and have a Range DFM and Auto Stop/Start bypass.

I will try to perform an actual calculation of fuel and mileage in a few days to determine of the dash is overly optimistic.

Should I be getting 25 MPG if I had 0W40 and the DFM and Auto Stop/Start was functional???