Interesting GM 2.7 Turbomax failure and tear down

You can find a blown example for every engine produced. Doesn't mean it's a flaw in the engine, everything we produce has the potential to have a statistically weak part or two. The question is, are these engines on the whole, reliable?

I was shocked by the state of that turbo. Hopefully that is not at all common.

I always heard really good things about these engines, especially the updated variant at 430 lb/ft torque.
Given all the internal damage and the state of the turbo, I question the OCI that was employed. My 3.5 Ecoboost is on the original turbos and I haven't babied it at all. Doesn't mean there isn't some wear, but it's not kaput yet.
 
I Do Cars is my favorite YouTube channel. Eric's teardowns has become part of my Saturday night entertainment (yes, sad, sorry).

Realize, this engine had 146,000 miles on it. So, could be worse.

I've been interested in this engine because they use it in the CT-4 Cadillac. 300 hp in one of those smallish cars sounds like a lot of fun.

From what I've read about these engines, in part from here, they can burn some oil. I wonder if this vehicle was ran low on oil, which trashed the bottom end?

These are complicated engines. The variable lift cams, cylinder deactivation (I think), cast iron reinforcements in the pistons. Lots of stuff going on. Maybe too complicated for its own good?
 
And second thought; I find it concerning how many examples of broken engines we can find these days, where they're running roller lifters. It happens to hemi, pentastar, cummins, this 2.7, the ford 7.3 (and presumably 6.8), the two GM v8s (5.3 and 6.2) and probably a bunch more but these are "stuck in my head" as they are the engines I've researched the most and either owned or been interested in purchasing at some point.

Is there something about roller lifters that we can't seem to reliably build these anymore?
Your last sentence….with the exception of one last company, we (United States) aren’t making lifters.
https://www.enginebuildermag.com/2024/02/deep-dive-on-lifters-with-hylift-johnson/
 
These are complicated engines. The variable lift cams, cylinder deactivation (I think), cast iron reinforcements in the pistons. Lots of stuff going on. Maybe too complicated for its own good?
Anecdotally these engines are stout. I browsed some threads where some fleet managers chimed in and said they've had no issues. I think this one had a oil issue.
 
And second thought; I find it concerning how many examples of broken engines we can find these days, where they're running roller lifters. It happens to hemi, pentastar, cummins, this 2.7, the ford 7.3 (and presumably 6.8), the two GM v8s (5.3 and 6.2) and probably a bunch more but these are "stuck in my head" as they are the engines I've researched the most and either owned or been interested in purchasing at some point.

Is there something about roller lifters that we can't seem to reliably build these anymore?
Small diameter roller (by my calculation) traversing approx 10 linear feet second at 2500 RPM,
Add in variable loading in the thousands of lbs per sq in. on the roller needles or (worse) balls
Lots of heat generation. Then if you float the valvetrain add high tonnage impact.

Possibly better oiling for heat transfer would help. But you do not want to introduce skating.

- Arco
 
I Do Cars is my favorite YouTube channel. Eric's teardowns has become part of my Saturday night entertainment (yes, sad, sorry).

Realize, this engine had 146,000 miles on it. So, could be worse.

I've been interested in this engine because they use it in the CT-4 Cadillac. 300 hp in one of those smallish cars sounds like a lot of fun.

From what I've read about these engines, in part from here, they can burn some oil. I wonder if this vehicle was ran low on oil, which trashed the bottom end?

These are complicated engines. The variable lift cams, cylinder deactivation (I think), cast iron reinforcements in the pistons. Lots of stuff going on. Maybe too complicated for its own good?

I found his channel some time ago and was intrigued by his good natured delivery.
I watched nearly all his videos over a weekend and thru that week..
I do watch every week also..
 
I watched his video because I bought a 2025 Colorado with that motor. It is a great driver more torque than my V6 and V8 Dakotas (1990s).

It seems like a well designed and constructed power plant. Steel oil pan now. Time will tell.
 
I watched his video because I bought a 2025 Colorado with that motor. It is a great driver more torque than my V6 and V8 Dakotas (1990s).

It seems like a well designed and constructed power plant. Steel oil pan now. Time will tell.
With many, many in fleet use-they have already passed the "time thing".
 
I've watched a bunch of "I Do Cars" videos and it seems like every single one has him doing something that makes me think, "Man, this guy doesn't seem to know what he's doing. Maybe he's not a great source of information."

For example, in this video he has trouble removing a PCV pipe. A very simple plastic pipe that requires squeezing the connection and pulling to remove. He attacks it with a flat-head screwdriver while exclaiming, "How does this work? It looks like it's a one time use? But why would they do that unless you just have to buy a new one?"

Like, really? You're going to give a detailed failure mode analysis of a very complex mechanical system but can't figure out a common plastic pipe connector?

You do realize he does some of that for comedic effect, yes?
 
I watched his video because I bought a 2025 Colorado with that motor. It is a great driver more torque than my V6 and V8 Dakotas (1990s).

It seems like a well designed and constructed power plant. Steel oil pan now. Time will tell.
I would imagine that having that engine in a Colorado is a Hoot!! V8 equivalent power with 4 cylinder weight. My Tacoma is similar, making it rather sporty to drive since it’s not as nose-heavy. I too don’t see one internet video as cause for alarm - I hear nothing but good things about this engine. And also, a high performance design like this is going to want good oil, on time. I would have no problem owning one.
 
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I find it sort of weird that the engine showed so much damage in virtually all moving parts, but there was no bad varnish or sludge. So the oil was serviced, too bad we can't know what was the root cause of failure and how long it took to trickle down to all other parts.
 
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Given all the internal damage and the state of the turbo, I question the OCI that was employed. My 3.5 Ecoboost is on the original turbos and I haven't babied it at all. Doesn't mean there isn't some wear, but it's not kaput yet.
You would think that, yet there was no sludge, let alone visible varnish in the internals at ~144K miles. Could it have been washed away from excessive fuel dilution of the oil due to a failed HPFP? If this were the case, there had to be symptoms that were being ignored, leading up to the failure.

Based on some other GM boards I'm on, if the HPFP starts leaking fuel into the engine, the fuel vapors get drawn into the intake from the PCV system, which throws the fuel trims way off. You'll have the MIL lit, etc..etc.
 
Eric never claims to be an expert tech, his business is finding what is usable and selling it for a profit; he throws some comedic moments in for the audience as mentioned.

I watch the channel a decent amount, not because I wait for a “who done it” moment of failure; more because I enjoy seeing the engineering in different engines and hearing which engines commonly come up for sale because they fail so often or what issues he tends to see regardless of the conjecture on the cause. When he did the Mazda 2.5, seeing how the piston design took cues from diesel pistons was neat, mainly because my wife has one. I like the channel as an engine nerd.
 
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