Cadillac XT5 Engine problems by year

evasive maneuver, especially at low speeds where pedestrian and parking-lot conflicts occur. Suspected root cause per owner reports and GM service documentation: engine coolant thermostat failure triggers a false engine temperature signal, and the electric power steering system reduces assist as a thermal protection response. Companion symptoms reported: inoperative/incorrect temperature gauge, cooling fans running at high speed continuously, A/C performance loss, DTC P0128. Manufacturer documents: Cadillac Service Bulletin 20NA215 (corrects "Steering Assist is Reduced Drive with Care" on 2021 XT5); GM Service Bulletin 17-NA-284 (2017-2018 XT5/GMC Acadia, reduced steering assist message with DTC C0460 Sym 5A, steering angle sensor trim error); GM Special Coverage N252508350 for the engine coolant thermostat (15 years/150,635 miles, expiring March 1, 2036). The vehicle carries a rebuilt title, so GM's warranty block applies and the owner may be denied the special-coverage remedy that a safety recall would guarantee to all owners regardless of title status.

"Steering Assist Is Reduced - Drive With Care" warning and a check-engine light. The steering felt normal despite the warning; I am not claiming an actual loss of steering. The temperature gauge has remained on cold, and the air conditioning has malfunctioned. The exact date the steering warning first appeared is UNKNOWN. On October 21, 2026, another Chevrolet dealership documented diagnostic code P0128 and recommended thermostat/coolant-temperature-related repairs. Those repairs have not been performed. The manufacturer was contacted and declined repair assistance. Dealerships have inspected the vehicle; I am not aware of a separate inspection by the manufacturer. I am concerned about the persistent shuddering at highway speeds and the warning of potentially reduced steering assistance. The cause of the shuddering and its relationship, if any, to the other symptoms remain unconfirmed. I still have the vehicle. Repair records, diagnostic information, and photographs of warning messages are available.

The vehicle would not restart and was left immobilized in the middle of traffic, creating a serious risk of a collision. The "Low Battery" warning appeared only after the engine had stopped. There was no indication of a low-battery warning before the shutdown. A check of the vehicle's VIN showed no outstanding safety recalls. We are concerned that an electrical, engine-control, or power-distribution malfunction caused the sudden shutdown and loss of steering assistance. The exact cause has not yet been established. We request that NHTSA review this incident as a potential vehicle safety defect because an unexpected shutdown and loss of steering assistance in moving traffic creates a substantial risk to occupants and other motorists.

at the time of the failure. Had this occurred at highway speeds or while crossing an intersection, the sudden loss of propulsion could have significantly increased the risk of a crash. This unexpected loss of power increased my risk a potential highway hazard. The vehicle was subsequently inspected and diagnosed by an authorized Cadillac dealership. The dealership determined that the engine suffered an internal mechanical failure, including rod bearing failure and metal contamination throughout the engine. The dealership advised that the engine required complete replacement. The vehicle has been properly maintained and serviced. There was no owner misuse, neglect, overheating event, or other known condition that would explain such a catastrophic failure. The engine failed unexpectedly and without any prior warning to the driver. I am submitting this complaint because a sudden engine failure resulting in immediate loss of power presents a significant safety concern. I believe NHTSA should investigate whether similar failures have occurred in other 2020 Cadillac XT5 vehicles and whether a manufacturing or design defect may exist that could place other drivers at risk.

back to the dealer, where it was diagnosed with an internal leak in the engine. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 30,000.

purchased from Carvana. The vehicle was taken to the dealer, who determined that the brakes and rotors, front control arms, radiator, unknown sensors, and several other unknown parts needed to be replaced; however, the contact stated that the recommended repairs were not related to the failure. The vehicle was towed to the residence. Carvana was contacted again and referred the contact to the second dealer, Herb Chambers Cadillac of Warwick (1511 Bald Hill Rd, RI-2, Warwick, RI 02886), who determined that the computer was not communicating with the key fob, and the coolant sensor, the air conditioner, and several other unknown parts needed to be replaced; however, the dealer informed the contact that they were unable to file a claim with Carvana to repair the vehicle. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 68,000.

strain on the brakes to slow down. I pulled over and initially shifted to neutral, but the engine was still revving high (4000 rpm observed). Then I placed the car in park which did not change the high RPM. Then I shut off engine and let it rest. Then I turned auto back on and all was normal. The problem has not yet been reported to dealer but will occur in coming days. There were no prior symptoms, problems, or warning lights on dash display prior to this occurring.

(Engine Coolant Temperature Below Thermostat Regulating Temperature). The dealer explained that a malfunctioning thermostat caused the steering assist reduction message to appear. However, at no point did the vehicle illuminate a Check Engine Light, despite the presence of an emissions-related fault code.I am concerned for several reasons:A critical engine fault (P0128) did not trigger a Check Engine Light, leaving me unaware of any underlying issue. The vehicle reduced power steering assist as a result of an unrelated thermostat malfunction, creating a sudden and unexpected increase in steering effort. This behavior poses a safety risk, particularly in situations requiring quick steering response or low-speed maneuvering.Cadillac has issued Service Bulletin 17NA158, which acknowledges that thermostat or coolant-temperature-related issues can trigger steering assist warnings. This suggests the manufacturer is aware of the problem, yet no recall or corrective action has been issued.Given that steering assist reduction directly affects vehicle control, I believe this issue warrants investigation. A driver should not lose steering assist because of a thermostat fault, nor should a vehicle fail to illuminate a Check Engine Light when a diagnostic code is present.I respectfully request that NHTSA review this matter to determine whether a safety-related defect exists in the 2018 Cadillac XT5 and similar GM vehicles. Sumitting this for my mother. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

and removed. The contact stated that coils were damaged, and the thermostat housing was cracked. The vehicle was repaired, but the failure recurred. The local dealer was contacted, who determined that the catalytic converter had been replaced, but the failure persisted. The dealer informed the contact that the parts were on backorder. The manufacturer was not contacted. The failure mileage was approximately 100,000. The VIN was not available.

vehicle. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was notified of the failure but provided no assistance. The contact was advised to take the vehicle to the dealer for assistance. The failure mileage was 40,000.

had 80,805 miles so I had to pay $1010 to have it replaced by an outside repair shop. The technician says since we had to have them both replaced and the car is only 8 years old, it is probably a design flaw. He told me to report it. I see another complaint for the same thing and I see they did a recall on some from California vehicles for something with the catalytic convertor and a recall on some in 2022 and 2023 vehicles for an issue with the catalytic convertor. I expected better from GM and Cadillac. I wonder how many other Cadillac XT5 owners have had this problem but haven't known to report it. You should contact the Cadillac dealerships and see how many they have changed out.

Care. The dealership has test driven the vehicle several times and has been unable to replicate the problem. However, I do have an audio recording of the engine's idle speed at various points during one incident.