when car sits for awhile lifter noise very loud for about 3seconds then quits and no more noise until it sits again.

 

Check oil level

 

may need adjustment or if hydraulic then may want to replace them, check if ur losing oil first or any smoke at the exhaust when the noise happens.

 

It's pretty typical for the vq35 motor especially if it sits for more than a day. All of the oil drains back into the pan and it takes a second for the pressure to build back up. If it happens all the time you need to check your oil.

 

You definitely need to check your oil, when was it changed last? There's another possibility, our Infinities make a strange grinding noise when they're started but it's the VDC engaging but only lasts 2 seconds. Could that be what you're hearing?
Gary

 

Multiple issues which could be the common timing chain tensioner or the VTC sprockets. It has to do with oil needing to get up to pressure during start up on the timing chain tensioner. Depending on the type of oil filter you use and how long the car sits for is if you have the noise. This issues has been going on for a long time on the VQ platform and if you really want to spend money then you can overhaul your timing components like guides, tensioners, chains and sprockets. More thank likely this is the component you need to change.





Also I am no master technician but just a regular joe schmoe but I do believe our vehicles do not have adjustable lifters but instead have shims that are used to bring that back in spec. Then again I would recommend you do some research and maybe hit up a qualified master infiniti technician.


Here is the sounds of it listen to the first start up and ignore the rest. Is it the rattle you hear around 7-9 second mark.



http://my350z.com/forum/forced-induc...tensioner.html