Your Nissan's timing chain ensures the valves on the engine close and open at the proper intervals. The timing chain must have the right amount of tension to keep the crankshaft and camshaft rotations synchronized and the engine valves opening and closing at the correct intervals. The Engine Timing Chain Tensioner ensures the timing chain in your Nissan Maintains the correct tension level to keep your engine operating as it should. Eventually, your vehicle's timing chain can loosen. The Engine Timing Chain Tensioner is there to make sure the timing chain stays in place and under the appropriate amount of pressure, even if any stretching occurs. If the Engine Timing Chain Tensioner on your vehicle is broken or worn out, the timing chain could lose tension and fall out of place. This could cause the timing chain to break if the vehicle is running when it happens. If the timing chain isn't functioning, the valves and pistons can collide, and your Nissan's engine will be unable to run. One obvious sign of an Engine Timing Chain Tensioner that needs to be replaced is a rattling sound coming From under the hood. A metal-on-metal sounding rattle could signify that your timing chain has lost tension and might be worn out. Over time, a rattling loose timing chain can lead to other issues, such as oil leaks. If you believe your Engine Timing Chain Tensioner is damaged or worn out, it's important to have a professional Nissan technician inspect and repair or replace the tensioner, as it can be a difficult process accessing the Engine Timing Chain Tensioner. If you need to replace your Engine Timing Chain Tensioner, replace it w/ a new OEM replacement tensioner From Nissan Parts. Find your closest authorized Nissan service center for help w/ professional installation. This Engine Timing Chain Tensioner fits your Nissan Frontier 2005-2019, Nissan NV1500 2012-2020, Nissan NV2500 2012-2020, Nissan NV3500 2012-2020, Nissan Pathfinder 2005-2012, or Nissan Xterra 2005-2015. See the What This Fits tab for more details. Xterra. Adjuster. Crank To Cam. Primary chain. Nv Full size Van.