Blown engine

[NorCal Blackwing]

UPDATE: picked up the car today , drives fine , apparently they had a engine replacement in stock, but suprised it doesn’t come with any additional warranty , also from what it sounded like they just put a 6.2 in it , and put the super charger back on , is there not a specific engine for it or anything like that ? It’s just like any other 6.2? And he said break in is 500 “just drive it normal then you can rip after 500 miles “ no oil change or anything needed ,?!? Is this true someone help me lol

If I'm reading this right you said they replaced the entire engine, not replaced components in the engine? If that's right there is no way that a Cadillac dealer would drop a random engine in there, even if it was possible to do that and I have doubts. You're good - if it's true that they corrected the root cause you may now well have a 'bulletproof' LT4 (as long as you observe the break in period lol)

 

[Argent86]

Change oil early (500-1000 miles). Break-in bits need to be flushed out.

I'm also priming by fake-starting my engine if it sits more than a couple days - push start button and then hit stop before it fires - in an effort to pre-lube the thing. This may not do a dang thing but I only get 1 chance to baby the bearings. I get some extra blue smoke from flooding but she fires up boy howdy!

oh wait, extra gas blowing past the rings can't be good

 

[blkout]

True but, the LT4 long block is very specific.

Of course. They replaced it with an LT4 long block.

 

[Jakemey]

Here’s the part numbers and the description from tech also is there a way to physically tell if it is the lr4 like numbers or what not on the engine, also in the last pic it said the eun(engine unit number) changed. Is there a way to use that and see ? Thanks for all the help everyone i really appreciate it it !! So i should get an oil change around 500-1000 miles , i asked him he said no but that doesn’t sound right , and he never explained the break in lol like so there rules of rpm or speed or anything ?

 

[RDATLTE]

Of course. They replaced it with an LT4 long block.

@Jakemey doesn't seem so sure.

 

[RDATLTE]

Here’s the part numbers and the description from tech also is there a way to physically tell if it is the lr4 like numbers or what not on the engine, also in the last pic it said the eun(engine unit number) changed. Is there a way to use that and see ? Thanks for all the help everyone i really appreciate it it !! So i should get an oil change around 500-1000 miles , i asked him he said no but that doesn’t sound right , and he never explained the break in lol like so there rules of rpm or speed or anything ?

Per this, you're good: Genuine GM Parts 12708597 - 6.2L LT4 "Blackwing" Wet Sump Engine Assembly, Service

 

[BW56M]

@Jakemey, the work order only lists 8 quarts of Mobil 1 supercar. Check your oil. LT4 requires 9 quarts.

Better safe than sorry.

 

[Jakemey]

Per this, you're good: Genuine GM Parts 12708597 - 6.2L LT4 "Blackwing" Wet Sump Engine Assembly, Service

Thank you so much where did u find that , when i searched it just said gm 6.2

 

[RDATLTE]

Thank you so much where did u find that , when i searched it just said gm 6.2

Google-fu!

 

[CB34]

UPDATE: picked up the car today , drives fine , apparently they had a engine replacement in stock, but suprised it doesn’t come with any additional warranty , also from what it sounded like they just put a 6.2 in it , and put the super charger back on , is there not a specific engine for it or anything like that ? It’s just like any other 6.2? And he said break in is 500 “just drive it normal then you can rip after 500 miles “ no oil change or anything needed ,?!? Is this true someone help me lol

Can you provide a print out of your receipt from the shop with the part numbers they replaced?

 

[hawk02]

Wow! I’m actually more shocked that the dealer had an LT4 block sitting in stock than the fact that the engine failed. That’s a serious chunk of money to have tied up in inventory. Most dealers don’t keep something like that on the shelf—it’s usually ordered in as needed or shipped directly from GM as a short block or long block under warranty.

 

[blkout]

Wow! I’m actually more shocked that the dealer had an LT4 block sitting in stock than the fact that the engine failed. That’s a serious chunk of money to have tied up in inventory. Most dealers don’t keep something like that on the shelf—it’s usually ordered in as needed or shipped directly from GM as a short block or long block under warranty.

It could have been at another dealer or likely GM has these in a warehouse ready to ship to dealers as needed. With the ZL1 and C7 Z06 no longer being produced, I'm sure there's a surplus of LT4 long blocks available right now.

 

[hawk02]

It could have been at another dealer or likely GM has these in a warehouse ready to ship to dealers as needed. With the ZL1 and C7 Z06 no longer being produced, I'm sure there's a surplus of LT4 long blocks available right now.

I highly doubt GM has a stockpile of LT4 long blocks. The C7 Z06 and CTS-V v3 were done back in 2019, and Camaro production wrapped in December 2023. That leaves the 5BW as the only GM platform running the LT4 for the past 18 months or so. With Cadillac moving around 2,000 5BWs per year, there’s no real reason to sit on extra engines.

GM does offer the LT4 as a crate engine, but volume there isn’t massive either. Most likely, that long block was ordered for another build and never got used. OP just got lucky that his replacement happened so fast.

 

[blkout]

I highly doubt GM has a stockpile of LT4 long blocks. The C7 Z06 and CTS-V v3 were done back in 2019, and Camaro production wrapped in December 2023. That leaves the 5BW as the only GM platform running the LT4 for the past 18 months or so. With Cadillac moving around 2,000 5BWs per year, there’s no real reason to sit on extra engines.

GM does offer the LT4 as a crate engine, but volume there isn’t massive either. Most likely, that long block was ordered for another build and never got used. OP just got lucky that his replacement happened so fast.

We'll never know, you have your opinion and I have mine apparently.