Hubby and I noticed the AC would suddenly not cool, sound of running motor and would require turning off the engine. Then AC would go back to working beautifully. This happened once or twice over a week period, then started happening daily with a check engine light. Brought it in to our regular Firestone mechanic found no issues with engine or AC. (Car had 175,000 miles.) Took Enclave to GMC and they also found no issue with engine or AC and claimed everything was working and they ran AC for awhile with non issues. Service provided was new air filter and Freon. Problem persisted and within 3 weeks had total engine failure.