Every variable valve timing system is slightly different, but there are three general rules to follow to ensure proper performance. First, regularly service the engine oil and filter. Second, use the manufacturer’s required engine oil type. Lastly, service the engine oil and filter after you install new solenoids or sprockets.
A few specific applications that are known to have high failure rates for VVT solenoids include the GM 2.4L and Toyota 3.0L and 3.3L. As you can see below, NAPA® Echlin® has these applications covered.