One problem related to transmission noise has been reported for the 2003 Cadillac CTS. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Cadillac CTS based on all problems reported for the 2003 CTS.
The original transmission was replaced at 600 miles due to a rattling noise in 2nd and 5th gear. At 800 miles the noise reoccurred in the new transmission. Cadillac claims to be working on a fix, however no one in the Cadillac organization can comment on when the fix will take place. The noise continues to get worse and continues to get louder.