One problem related to engine failure has been reported for the 2005 Cadillac CTS. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Cadillac CTS based on all problems reported for the 2005 CTS.
Engine quit without any warning (noise, engine warning light) going 55mph down highway. Engine is ruined. I bought this car new and kept it for almost 8 years. I had all routine and recommended maintenance done by dealer. I sold this to my friend who this happened to. I have determined this was probably caused by the gm recommended 10,000 miles oil change. Engine failures apparently have been happening for quite some time according to the internet and gm or my dealership never once told me to have the oil changed sooner or warned me about this. I feel this is a real safety hazard. If I would have pulled out on the freeway where I normally do to blend into 70 mph traffic and the engine would have failed, I would have had no place to pull over and coast to a stop as there isn't a shoulder for several yards. I could have very well been hit from the rear and a chain reaction accident with potential loss of life could have occurred.