2024 CT5-V Blackwing engine failure

[Motobones]

I am new to this forum, I just purchased my CT5 a few months ago and only have 3128 miles on it but the engine has failed in what I believe is the exact same way that the engine failed in the Car and Driver long term test car. I was religious about the 1500 mile break in and I haven’t ever used launch control or driven it very hard. I was planning on doing those things I just hadn’t had the chance yet. About 2 weeks ago as I was leaving my driveway I felt a judder like if you were to lug the engine in a manual transmission car (mine is an automatic). I didn't think too much about it but at low rpm in a higher gear say 7 or 8 it would do it again every once in a while. I was getting concerned and about to ask the dealer about it when it just quit completely when I was driving in town. Luckily it stopped where I could get out of the way of traffic. I had it towed to the dealership and they have told me the engine is locked up and they are working with Cadillac on next steps. I’m guessing what I thought was a transmission or rear end problem was an engine misfire that caused a catastrophic failure. I still think it is weird that there were no indications or alerts that anything was amiss until it just packed it in. I’m bummed out because I really love this car, but this is not the first time I have had a new car need a new engine. Back in the early 2000’s I had a E46 M3 that had a bad set of bearings and had to have the engine replaced after a few thousand miles so poop happens. Still no fun.

 

[ukcats12]

You should share your engine builder so everyone with the same builder can freak out a bit.

 

[Finally-a-V]

That's some bad news, and sorry to hear it. Hope it gets resolved quickly. Keep us in the loop as you go forward.

 

[Likuid]

Getting the point where we almost needs a sticky for all these engine failure threads. Seems like a new one every week or two.

 

[Motobones]

I don’t know who the engine builder was but I will look when I get the chance. I wouldn’t blame them. If it turns out like the BMW then it was a bad batch of parts the killed the engine. It’s up on the rack at the dealer now and they tell me they hope to know more next week. I’m even more bummed because I have a 2016 Z06 with a manual transmission that I have beat on pretty hard and it hasn’t had any issues which is part of why I wanted the Blackwing. I’ll post when I know more.

 

[NorCal Blackwing]

Getting the point where we almost needs a sticky for all these engine failure threads. Seems like a new one every week or two.

Here's what I've been able to gather so far

AACaptRet, MY2022, ~5000 miles, bottom-end
Nadnerb, MY2023 ,~200 miles, bottom-end
Carguyshu, MY2022, ~3500 miles, bottom-end
CT4BW757, MY2023, ~10000 miles, tick (lifter?)
CT5BWEnthusiast, MY2023, ~21000 miles, tick (lifter?)
SS Performance, MY2024, ~5500 miles, ? bottom-end ?
Magnetic Flux, MY2024, ~6500 miles, lifters
Philsblackraven, MY2022, ~14500 miles, ?spark plugs?
Motobones, MY2024, ~3128 miles, ???

For context 9/1942 CT5-VB in the registry on this site

 

[MookdocOE]

I don’t know who the engine builder was but I will look when I get the chance. I wouldn’t blame them. If it turns out like the BMW then it was a bad batch of parts the killed the engine. It’s up on the rack at the dealer now and they tell me they hope to know more next week. I’m even more bummed because I have a 2016 Z06 with a manual transmission that I have beat on pretty hard and it hasn’t had any issues which is part of why I wanted the Blackwing. I’ll post when I know more.

Sorry to hear that mate! You broke her in good but had shitty luck? I don't think the next one will do you like that!

 

[BimmerFan]

Bummer. Best of luck, keep us posted!

 

[Motobones]

Quick update, the dealership is communicating with Cadillac who have asked for more data from the computer and have had the dealership pull the intake but nothing further. The service department is waiting to hear what Cadillac wants them to do next. He did tell me that it wouldn’t turnover, they had to roll it into the shop on their skates, and they put a breaker bar on the crank and couldn’t get it to budge. So that doesn’t sound too good. Now both me and the dealership are waiting to hear what Cadillac wants to do next.

 

[Motobones]

So, I have an update with photos. It turns out it was not a misfire and top end problem it was a bottom end problem, bad bearings. It spun two of the rod bearings, one so badly that it essentially welded itself to the crank and that’s what locked it up. This is the same mode of failure as the engine in the 2003 M3 that I had to replace the engine in. That one lasted about 7500 miles before it went. Cadillac is going to replace the engine and they have one available. The dealership will have it next week and get it installed as soon as they can. I’m not sure what they are trying to show in the first image except maybe the discoloration of the metal from the heat.

 

[DCV]

The first pic shows a crack in the rod. Look in upper left where it says 10 stamped into it.....to the right of that.....a crack. , you can see it.

 

[Motobones]

I see that now. Wow, that’s really not good. I guess it’s good it seized before that came loose and came out of the block.

 

[shbox]

Fortunate they have an engine available so quickly. Some others have had to wait much longer. Good luck going forward!

 

[BimmerFan]

I thought these connecting rods were fractured before assembly instead of being cast in two pieces or drilled out, so that could be normal. Perhaps not.

Linkie: Fractured Connecting Rods

 

[565565]

Makes you wonder what changed in the newer gen non SC 6.2s and LT4s that the rod and main bearings are a problem when they weren't before?

Different bearing supplier? Redesigned oiling system? Metal machining debris (what the toyota 3.4L TT failures were blamed on). Something else?

 

[BimmerFan]

Makes you wonder what changed in the newer gen non SC 6.2s and LT4s that the rod and main bearings are a problem when they weren't before?

Different bearing supplier? Redesigned oiling system? Metal machining debris (what the toyota 3.4L TT failures were blamed on). Something else?

When you consider all of the conditions that an engine has to go through, cold starts, different oils, the fact that the block is sand cast and could easily have leftover particles in the various oil galleries, temperature variations, high RPMs, high loads (think towing) and just the sheer number of things moving around for years and years... I'm just amazed that these things work at all.

 

[ukcats12]

the fact that the block is sand cast and could easily have leftover particles in the various oil galleries

This is actually a big problem with the current C43. Tons of engines had molding sand let in the block and it’s nuking the engines within a few hundred miles.

 

[OnMSRP]

I don’t know who the engine builder was but I will look when I get the chance. I wouldn’t blame them. If it turns out like the BMW then it was a bad batch of parts the killed the engine. It’s up on the rack at the dealer now and they tell me they hope to know more next week. I’m even more bummed because I have a 2016 Z06 with a manual transmission that I have beat on pretty hard and it hasn’t had any issues which is part of why I wanted the Blackwing. I’ll post when I know more.

Hopefully GM is responsible about this and issues a recall.