2023 L87 New Motor. How does this cylinder sound?

[0x_2a]

I put a remote-mic on the oil dipstick close to cylinder 4 (passenger side, second from front) and drove around the neighborhood. Compare with the rest of the engine 10 seconds in, when AFM shuts off the cylinder.

How does it sound to you?

 

[Boston]

I put a remote-mic on the oil dipstick close to cylinder 4 (passenger side, second from front) and drove around the neighborhood. Compare with the rest of the engine 10 seconds in, when AFM shuts off the cylinder.

How does it sound to you?

these engines have DFM and can shut down any of the 8 cylinders unlike the earlier engines with AFM that shut down the same 4 cylinders

 

[jfoj]

L87 has DFM so it can turn almost any combination of cylinders off or on between None and 8. Not sure if the system will actually allow the engine to operate on less than 2 cylinders under load??? But the system can collapse all 16 lifters during DFCO (Decel with Fuel Cut Off).

If you are saying the first 10 seconds is with the microphone near cylinder number 4 and after 10 seconds the microphone is located elsewhere, then there may be an issue around #4. The first 10 seconds of the recording sounds fairly "Tappy" to me.

What you can do is repeat the test with the microphone in the #4 location, operate the engine in L9 which should disable the DFM system, have not confirmed 100% that it disabled the valves closing down under DFCO (Decel with Fuel Cut Off) or not.

Guessing that just because you grabbed a recording you feel something may be going in with the valvetrain?? If this is a replacement engine, when was the engine replaced or do you know the engine build date of the replacement engine.

If the engine was replaced before Aug/Sept 2024 then it is likely an engine built before July 1, 2024 and if your vehicle is in the recall window, you should get the engine replaced again if the engine build date is before July 1, 2024 unless GM has changed the rules on the recall.

 

[0x_2a]

@jfoj thanks, yeah this is my 3rd motor (replaced as part of the july 2024 cutoff recall).

Here's what's in first oil change at 2,000 miles on motor #3... so tired of GM ********.

 

[jfoj]

Man your whole situation is not good. Save your oil filter and cut it open as well if you still have it. I just cut the first oil filters open on my 2024 and 2 - 2025 6.2l. all had some metal the 2025 with 1200 miles looked the worst. I also did not like the oil color of the 1200 mile 2025

Document everything you can on motor number 3, I do not have a good feeling about#3 between the noise and what the oil drain pan looks like

Search my user name and Post Pictures of Your Oil Filter Opened Up.

GM needs to be doing random pulls of oil filters and cut them open after Cold Testing and track what is going on, this is crazy and bad for all of us owners.

 

[0x_2a]

Time for my exit, traded in for a Sequoia. I'll share some details for the curious. Thank you all for the collaboration here.

Yukon Recap
- Bought 2023 GMC Yukon Denali Ultimate for $99,487 September of 2022
- First engine blew at 22K miles, 7 followup service visits to fix repair mistakes
- Second engine recalled at 46K miles, 2 followup service fixes since April
- Third engine at 48K miles shredded its cam bearings, got forbidden glitter, dealer said no fix until it throws a code.
- Mag ride leaking as of 2 weeks ago, dealer would not fix
- Settled lemon law case (started Dec 2024) at $10K payout. Best I could do outside of going to court.
- I'm quitting my part-time job as a Yukon-owner

Yukon Trade-in Value
- Yukon value (mint condition) -- First offer was $59K, got them up to $64,000 (final 36% depreciation).
- Carvana offered $62K, KBB said $61K
- Before the recall it was $75K in March, down $11K in 4 months.

Thoughts on Sequoia (Platinum Trim) vs Yukon

Pros
- Size is roughly the same (Yukon 210"x81"x76", Sequoia 208"x80"x75")
- Accelerates way faster, no 2-second lag waiting on DFM
- Transmission shift points feel more natural, steering + pedals more sensitive
- 4L Drive Mode electric-assist is stronger, pulled a stump out yesterday
- Twin-turbo's sound nice
- Active road-noise cancellation in the cabin is nice
- Hybrid battery assist doesn't get in the way, good "eco" mode
- Center console screen responsiveness is like an iPhone, Airplay works better
- AC is better, and I can reach driplines easily (Yukon drips it on the trans)
- Runs fine on 87 octane, but I'm running 93
- Seat massagers are better, has butt-mode
- Has built-in dashcam
- No headrest screens my kids never use, hit their head on
- Many annoying features can be changed with OBD2, no "Global B" ECU lockout
- Tighter turning radius
- No odd engine issues in the first miles (no concerning vibrations, noises)

Cons
- Couldn't find an "Ultimate"-like trim anywhere near me (1897, Capstone)
- A bit rougher / lower Ride, Yukon was better with Air + Magride
- Trans shifts feel more stiff, Yukon's was a little better
- Regenerative braking is good, but I don't like feeling it kick on/off
- Exhaust sound signature is meh, Yukon's was better
- JBL sound system is meh, Yukon's Bose was better
- Service has to deactivate "Enhanced engine audio", fake engine noise.
- Hitch compartment is a real PITA to open, need a flat-head
- Has more annoying "safety" features, beeps, warnings to disable
- Roof bars mount with bolts instead of quick-release
- Needs OBD-II to set default cruise/distance/sensor settings

 

[jfoj]

Sorry you had such a bad experience, you are probably not alone.

Understand after engine #3 with a fair amount of metal, you wanting to move on, cannot say I blame your decision. You also took quite a hit on the wallet as well.

Good luck with the Sequoia, with the twin turbos, change your oil often, the turbos can cook almost any oil and the dirtier the oil, the more it can cook the dirt in the turbos. On hot days or long runs allow the engine to idle for cool down 5+ minutes depending on the situation.