One problem related to engine clicking and tapping noises has been reported for the 1999 Cadillac Deville. The most recently reported issues are listed below.
The contact owns a 1999 Cadillac Deville. While driving approximately 60 mph, the vehicle stalled without warning. The contact heard a popping sound coming from the engine as steam accumulated on the windshield. The vehicle was not taken to the dealer for diagnostics. The contact inspected the vehicle and discovered that the head bolts had become loose from the engine. The vehicle was not repaired. The approximate failure mileage was 94,000.