Engine has had this noise since it was built, i have tried numerous oils, changing fuel systems, tuning ect but cant figure out what the issue is.

Before i just pay someone endless amounts of $ i would love some help identifying some potential things this could be that i can either check or give the list to the mechanic.

sometimes if car is not run for days i can hear a knocking noise for few seconds when starting.

http://i40.photobucket.com/albums/e208/Davis_711/G35%20Driver/Engine%20Noise_zpszlab8cfg.mp4
Thank you very much, really appreciate you guys help !

 

incase link above doesnt work
http://vid40.photobucket.com/albums/e208/Davis_711/G35%20Driver/Engine%20Noise_zpszlab8cfg.mp4

 

Sounds like lifter tick

 

Once engine starts sound goes away. Turn car off then start again and its ok. Must be left like an hour before sound comes back when starting. Does lifters do that?

 

most high mileage VQ motors do this. Mine does, just not as loud. I have 125K on mine.

I agree it's a lifter problem, once the oil pressure pumps them up, they are fine.

 

Also engine was rebuilt for FI, new everything inc tensioners.
Lifters should not be worn as they were new.
Would a correctly installed tensioner / guide / chain be an issue if i turn the car off once stated and then start again and no more noise until oil is all drained ~ 30mins +

may be a separate issue or the same but sometimes when initially turning over you can feel / hear a knock. ill try and get a video of this

 

I bet no one has written this before as i have spent alot of money figuring it out.

Here are the 3 things

1. Chain tensioner, a $80 part that fills with oil and pushes a rod out and puts tension on the chain, the initial few seconds of rattle can be this and then once oil pressure is up it goes away. If you turn car off and start again soon it will not happen until car is cold
http://www.courtesyparts.com/13070-t...4_715_716_725&

2. Cam gears, they have a spring that pushes a plunger and locks gear into place and allows the VCT solenoids to advance or retard , the spring and plunger breaks over time and will make nasty rattle noises, but they are $400 parts x2
http://www.courtesyparts.com/13025-s...4_715_716_725&

3. the cam gear covers, there is a little washer inside the middle of the cover like 50c size and it helps hold oil pressure in the cam gears, these are $50 part each
http://www.courtesyparts.com/13041p-...8-p-17111.html

I replaced every timing chain and guide and still had the issues before i replaced the gears and then only a tiny noise and then replaced the covers as mine had no washer for some reason and now noise 100% gone, no noise on start up at all.

This can cause P0011 and P0021 issues

No where has this been mentioned before..
It can throw a P0373 Engine Position Error code (no goggle search will tell you what that is but it means your cam gear/s are broken(