2018 Cadillac CT6 Engine Problems
- Complaints
- 3about this part
- Share
- 33%of 9 total for the year
- Median mileage
- 22,000miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 3 complaints about the engine of the 2018 Cadillac CT6, 33% of the 9 complaints for this model year. Where a mileage was given, the median is 22,000 miles.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“My Cadillac CT6 (2018) quit working while on the expressway. I was in the middle of no where, in georgia. This made for a very dangerous situation as the car suddenly lost all power going to the wheels while driving at approx. 75 MPH. I was barely able to get around traffic to be able to pull over as there was 0 power. When the tow truck from Cadillac arrived we were told we were not allowed to ride in the truck because of covid. We were made sit in the rain in 40 degree weather while I spoke with my home Cadillac dealer as well as the nearest to where I was. …”
NHTSA complaint #11389316, filed 2021-01, 22,000 miles“The brake makes a rattling and metal grinding sound, the dealership said nothing is wrong with the brakes, still problematic. The transmission shifts too hard. Dealer said nothing wrong. Yet cat kicks too hard.”
NHTSA complaint #11508253, filed 2023-02“Stuck Thermostat. Vehicle not achieving operating temperature in the correct time. ALL 3 of the people I know with CT-6's had the exact same issue this year.”
NHTSA complaint #11745961, filed 2026-06Related service bulletins
- 11026017Jun 5, 2025This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
- 11024485May 15, 2025The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the…
- 11020254May 7, 2025This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in…
- 11019503Apr 18, 2025This warranty administration bulletin provides policy information on vehicles outside of a California Emissions State who move to and register their vehicle in a California…
- 11017443Apr 2, 2025This service bulletin provides a repair procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3055 Set.
- 11017263Mar 25, 2025This bulletin advises the technician to flush the cooling system multiple times if oil has been found in the cooling system and replace the parts that may be contaminated due to…
- 11016942Mar 4, 2025This bulletin advises the technician to flush the cooling system multiple times if oil has been found in the cooling system and replace the parts that may be contaminated due to…
- 11014230Jan 31, 2025This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
- 11014233Jan 30, 2025This service bulletin provides service information to technicians on guidelines to replace Oil Cooler, Oil Cooler Lines and Oil Tank if the engine was replaced where large…
- 11013069Jan 9, 2025This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
Engine: other model years
Other parts of the 2018 Cadillac CT6
3 complaintsFuel system
2 complaintsSteering
2 complaintsBrakes
1 complaintsExterior lighting
1 complaintsForward collision avoidance
1 complaintsLane departure
1 complaintsBody and structure
1 complaintsSuspension
1 complaints
← All problems reported for the 2018 Cadillac CT6
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 28, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology