Hi there, popped around the forums asking about an X164 GL550 but I'll admit to flirting with the idea of a GL63 AMG (who among us hasn't). There are plenty out there on the market I could afford, but my main hangup is the M157. That engine sounds so incredible... when it's healthy. I'm not averse to the turbos or the complications that come with them, but that bore scoring issues terrifies me since it's the one thing I can't fix. Looking for some insight from owners on a couple of things.

-Mileage range on when this issue could crop up varies wildly. I've read anywhere from 60k to 120k miles. Wondering where on the low end mileage wise I should search for a used one.
-There are videos and threads out there suggesting something as simple as unplugging the low oil pressure solenoid (about 7 o'clock position on the front of the engine) can prevent the issue. Seems a little ridiculous and AMG engine has such a short-sited feature, but that's mid-2010s Benz for you. Has anyone tried this and if so, does it seem to be working?
-Some suggest a little bit of scoring on the "thrust" side of the cylinder is normal, wondering if there's a general visual guide for what's "normal" and what's too far gone.
-Others suggest wrapping the turbos since the heat exacerbates the issue. Wondering if anyone out there has tried that with any success.

I understand this probably reads like paranoia and the issue certainly seems far less common than the Internet would lead one to believe, and it definitely seems like an "it will or it won't" issue as a few have kept them past 150k, but I'm trying to make sure I dot my i's and cross my t's before spending a chunk on an SUV I'm trying to keep alive for a while. I'm not afraid of anything else about maintaining one of these, but that engine is the party piece and I'd love if anyone has any experience to share keeping one healthy for high mileage.

Most of the solutions read like wishful thinking, but I'm hoping I'm wrong.

 

I had a 2015 GL63 and drove it to 128k miles. I was the 2nd owner, and when I bought it, it had about 45k miles. Anyway, I never had any significant issues. No bore scoring, etc, or engine work. Needed to replace two of the air suspension shocks. But I liked the GL63 so much I just got a 2021 GLS63. Just look for consistent A & B services, oil changes, etc.

 

Look for one under 60k miles to lower the risk. The solenoid trick is common. Many owners unplug it to keep oil pressure up. It’s a band-aid, but it seems to help.
Minor scoring can be normal. Deep grooves you can feel are bad. You’ll need a boroscope to check.
Turbo wrapping might help with heat. No proof it stops scoring, but some do it. Get a thorough inspection. If it passes, know the risk and enjoy.