2004 - 2011 Cadillac Deville equipped with the Northstar Engine requires four platinum spark plugs. The recommended spark plugs are ACDelco 41-110 or NGK BKR5EIX-11.
If you are replacing the spark plugs yourself, be sure to follow the manufacturer's recommended torque specifications for the spark plugs and spark plug wires. Over-tightening the spark plugs or wires can damage the engine.
Spark Plug Replacement Interval
The spark plugs in a Northstar engine should be replaced every 100,000 miles. However, you may need to replace them more frequently if you drive in dusty or dirty conditions, or if you use low-quality gasoline.
Symptoms of Bad Spark Plugs
Bad spark plugs can cause a number of problems, including:
Engine misfires
Reduced power
Rough idling
Increased fuel consumption
If you are experiencing any of these symptoms, you should have your spark plugs checked and replaced if necessary.
