What is this engine noise- knock or just timing chain / tensioner? Engine is Nissan VQ35DE https://youtu.be/OsMNwD77DWY?

Dan: Web search

Web search: "VQ35 timing chain guide problem"

don r

To me, it sounds like connecting rod knock. Check the rockers with a feeler gauge to eliminate them being too loose, then drop the oil pan and see which connecting rod is loose by hand shaking them. You will see bearing flakes in the oil.

thebax2006

That sounds more like a valve or collapsed lifter. Those motors are very sensitive to the oil level and you need to change the oil and filter every 3,000 miles or every 5,000 miles if running synthetic oil. The timing chains go bad and the cam advance actuators start throwing codes if you don't.Still sounds like lifter or valve related noise to me.

FlagMichael: Cheap and easy to do

Cheap and easy to do: try an inspection of all the bolts that fasten the exhaust manifold to the heads. The VQ35DE was notorious among Pathfinder fans for broken exhaust manifold studs. The symptoms were as you describe - loud tapping when cold, dropping to a softer tap when warm. Exhaust manifold leaks sound eerily like metal tapping. EDIT - a sure indicator of an exhaust manifold leak instead of an internal tap is that the exhaust leak can't be heard through a mechanic's stethoscope (or screwdriver used as a stethoscope) anywhere on the engine.

Barry

May be piston slap and/or valve gear wear. I doubt a worn chain would quieten when warm. Use fully synthetic 5w-40 oil as this may delay failure! Don't buy Mobil. Get it at Walmart.

Anonymous

Sounds like a rod knock.

coxx

Change oil and filter.

The Jet Set Duo

Sorry- meant to say the engine makes a loud rattling noise when started then it quietens to like it is in the video. Only got the car yesterday (was sold as having a noisy engine)