Got a rattle or thumping or knocking noise not sure which one is which right now cuz it only happens when the engine gets warm & it's running at idle. You can rev it & hear the rattle also. Performance doesn't seem to be lacking.

Today 4/24/16
6 New NGK spark plugs & inspect coil packs - all good
*Noticed a little oil on some of the old plugs & they still looked good.

New Injen Intake system - all good

Last Sunday
New oil 5qts & oil filter - all good no flakes of metal
M/T fluid Nissan - Almost 4qts worth - all good no flakes either

New parts to be put on will be CNT High Flow Cats & DC Headers when I have time to do the work. I have a fuel damper with hose coming - Part number FPD55 for $68 bucks new.

Adding the new cats & headers i'm hoping that it's just a rattle from the heat shields when warming up. Also I heard the stock cats could be plugged up.

Changing out the damper isn't a bad idea either if you go by the Alldata TSB report.

My question is why is this noise occurring when the engine gets warmed up?
If a rod & cap is the culprit wouldn't a noise be heard right away at start up?

Other stuff I wanna look into is timing chain guides, timing chain tensioner & spinning my pulleys just to see if a bearing isn't f'ed up causing a noise.
But again should a noise be heard at start up if any timing chain guides are messed up?

Any feed back would be great. Thanks

 

Have you tried the disconnect a plug cable at a time to see if its knocking?
Compression test?
How is vacuum?

 

If it is rod knock/bearing etc you are going to hear it whether the plug is connected or not - the cylinder is still in operation.....

 

The test gives you an idea to isolate the issue.

Been there, done that.

 

Drive side cat was plugged & is now replaced with a CNT high flow cat & my engine is back to normal.