Some Cadillac CT5-V owners have reported that the cabin heater in their sport sedan will fail to generate heat, even after the engine has reached its normal operating temperature. Now, General Motors has identified the root cause of the issue and released a bulletin outlining what’s going on. Unfortunately, the solution isn’t minor, as it requires an entire engine replacement.
According to GM bulletin PIP6050, published March 14th, 2025, the issue stems from a defect in the engine block itself, which prevents heated coolant from reaching the heater core. More specifically, the defect involves a casting over in the rear coolant passages of the CT5-V’s twin-turbocharged V6 engine. This blockage restricts coolant flow through the heater circuit, starving the heater core of warm coolant while still allowing the engine to regulate its own temperature normally.
The bulletin advises technicians to first perform diagnostic flow checks through the heater core hoses. If coolant flow is severely limited, the engine must be replaced entirely. There is currently no alternative repair or workaround.
GM specifies replacement engine part numbers for both AWD (12708353) and RWD (12708354) configurations for the Cadillac CT5-V. The repair is covered under the powertrain warranty. The bulletin notes that this issue may affect units of the Cadillac CT5-V produced between the 2023 and 2025 model years. To note, this bulletin does not apply to the Cadillac CT5-V Blackwing, which is equipped with the supercharged 6.2L V8 LT4 gasoline engine.
As a reminder, the Cadillac CT5-V is powered by the twin-turbocharged 3.0L V6 LGY gasoline engine, which delivers a maximum of 360 horsepower at 5,400 rpm and 405 pound-feet of torque at 2,350 rpm. The V6 connects to the GM 10-speed automatic transmission as standard, and is available in both rear-wheel-drive and all-wheel-drive configurations. The CT5-V rides on the GM Alpha 2 platform, which it shares with the CT4 and sixth-generation Chevy Camaro. All CT5 model variants are assembled at the GM Lansing Grand River plant in Michigan.
Comments
What a major screw up!
Wow. A little voice in my head has been saying is the $60k price worth it. Pass.
I like my 4 cylinder CT5 just fine.
Unbelievable, where’s the quality control. Nothing has changed from the previous year car motors, how can Gm screw up something that should be bulletproof by now. Same engines for the 4 yrs or more.
This is beyond laughable. Has all quality control left the manufacturing processes at GM?
I understand people not wanting to buy a first yr model yr but this have been around for a while. Too many union members must be smoking weed on the job. Life long Gm buyer, 3 in my garage now but that might be changing soon.
I actually bought a first year CT5-V. In fact, it was the first one at my local dealer. The engine and trans were great, but electronically, it was seriously buggy. I can’t recall how many, many software patches it got. In fact, a mechanic friend plugged a scanner into it one day just for fun. It came back with over 50 “communication faults” which GM refers to as “spurious”, meaning “just ignore them”
Considering GM is focusing on EV`s and placing 4cy`s in what will be left of ICE vehicles they will offer… NO THANKS…
I would have bought a Blackwing if I had been in the market.
I replaced my 2020 CV5-V with a 2024 CT5-V Blackwing.
LOVE it!
From Roger Smith to Mary Barra, if nothing else at least gm management is consistent. Consistently atrocious!
Has GM released any numbers on how many 23-25 CT5-V’s have been affected or is it all of them? Also, what about 20-22 CT5-V, are they also affected or did this problem only start in 23?
My guess is they probably have no idea. Thus “No heat? New motor”.
Like the 6.2 truck lifter bores, QC should’ve caught the FIRST bad one versus letting it go for years.
These quality issues are among many things that show gm is a company completely void of leadership. In order to chase misguided visions of “all electric future”, “triple zeros”, and DEI scores, they completely neglected their current customer base. I’m sure gm’s layoffs of the month did not do wonders for quality.
Wow
Enough with blaming DEI! GM quality was dreadful in the 1980’s, when DEI wasn’t even dreamt of. This is more about the American obsession with short term results and share prices, over long term strategic goals such as quality-based customer loyalty.
Dear Jamie. In the 80’s DEI (didn’t earn it) was called ‘Affirmative Action’. Same thing, different name.
You are too wrapped up in Politics. Gen Lloyd Austin a West Point Grad and lifelong in the military with a long service record and commands was replaced as a DEI for Pete Hegseth. So DEI is just a term to replace who and what Trump doesn’t like with loyalists who are completely unqualified.
The heater in my 1995 Chevy Metro 3 CYL works really good.
Based of a Japanese vehicle, so that makes sense.
Yep, its a Suzuki Swift.
ICE have become an afterthought at GM they will push EVs until ICE cars are gone guality and innovation will suffer.
Sadly, quality continues to be a problem for GM. They are not alone. Ford leads in recalls and warranty expense. Toyota is facing a major recall to replace entire engines. Honda has has large recalls. Seems that the required speed to market and supply chain problems have overwhelmed makers quality control programs. Remains to be seen who can reverse this trend.
Not surprising when you consider that GM eliminated the Brand Quality department.
I have a 21 CT5V RWD and love it. Although I’ve had to replace all door handles now under warranty. No issues with tech otherwise. I knew that I was buying GM quality and not a Lexus. So, I will never be complaining about my purchase here.
What country was this POS engine block produced in?
More than likely it was produced in enabler to mediocrity’s weak, insignificant country.
NOT the best news ever, but at least they have a fix and its warranty, just hope people get it fixed without to much down time .
Keep up the good work, Mary .
I waited to purchase my Cadillac CT 5V the 20th anniversary after taking the car out in April while it was still cold weather. Istored the car four the winter. I noticed one evening when I turned on the heat and wasn’t getting very much heat if any at all, and had to rely on my electric seat heaters Now I understand what’s going on. the real question is how much damage is gonna be done to my car after they pull this engine and put a new one in what will mechanics forget to do or tighten or replace correctly so that I don’t have other problems with the vehicle after this has been done. Sadly disappointed in GM will think twice before making another purchase from GM.
I work in IT, where testing is required to make it correct.
This applies to cars, where testing is required to avoid issues like this.
Depending how many vehicles are affected, this recall could cost GM up to $700 million, despite this expensive recall Mary Buick Envision Made in China-Barra will still be paid $30 million/year. The cost of this recall should come out of Mary Buick Envision Made in China-Barra’s paycheck.
There must be a reason why Mercedes-Benz, BMW and Lexus sell 300,000/year in America while Cadillac struggles to sell 150,000/year on their own turf. All Cadillac executives should be fired.
This is so bad that it seems almost purposeful- Negative press about one of their last ICE sports sedans. “This’ll make ’em want an EV!”
Na it will just push customers to Lexus.
Atleast the intelligent ones.
I have a 2024 CT5-V (AWD) and the heater pumps out plenty of hot air…and in Canada, I need the heat! I’m lovin the car. The only issue was a creased leather seat (driver side) which was replaced with a slightly better version. The twin turbo V6 is quick, smooth and sounds great with the variable exhaust system. I test drove the 2.0 L 4-cylinder and it’s under-powered and sounds anemic.
CT4-V 2.7L 4CYL 380 TORQUE
CT5-V ENGINE SOLUTION
2.7L TURBOMAX 430 TORQUE
Not to be smart – but does the new engine have the same defect?
Replace the entire motor – rather than just the casting?
How come some castings have a problem?
How many out there are borderline? We won’t know until December!
Is the 3.0L engine in the CT5 Premium Luxury version also affected? It is essentially the same engine with a little less HP than the CT5-V. The article only references the CT5-V version.
I don’t know enough about the architecture of this engine, but usually the source of the coolant going to the heater core is a coolant jacket in the head or even the water pump itself. I would think if there were a casting issue, that could be rectified by opening up the blockage, even if it meant a bit of disassembly and grinding. That would save an immense amount of money and could be a quicker fix. Maybe GM doesn’t trust their dealer service techs to make this type of repair with repeated success.