Pathfinder Engine Knock while Engine is Cold

randy71

It sounds like a liffter tapping only while engine is cold and goes away after it is warmed up. i use 10w-30 castrol oil. If I went to a SAE 5W-30 would this help???? Or Hurt ???

asa

5W-30 is the recommended engine oil, right? It may not do much tho, as the 4.0L in my '06 Frontier does the same tapping thing as yours. I use 5W-30.

99accent

I once wrote about my valves tapping when engin was cold on my 03 pathfinder, I did get quite a few answers with help ,however I remember one person mentioned something about some tiny screws coming lose on the engine so they used lock tight to secure those screws, and its been an ongoing thing with some v6 engines,does any one have any idea of what or where those screws come loose on the engine ?

99accent

my pathfinder does this slight knocking very dull under he Right passenger side when its fully warmed up , if I let it cool off for 5 minutes it goes away but sure will be back when its fully hot at idle in park,most mechanics say don't worry about it just drive it ,I really would like to know what the possibility's are here are some in my searches . worst case Rod knock , piston slap, wrist pin wear, flex plate on tyranny cracked, timing chain tensioners,right manifold on block loose,Fan belt pulleys one worn ,fan hitting the shrowd. I'm baffled , the manual says don't run this engine without a battery or you can ruein the computer box, so is it OK to take the fan belt off and run it with out the alternator turning just to determine where the noise is ?