Hey,

i have an 04 350Z DE auto with an engine knock on the drivers side of the engine only when at operating temperature. When I start it cold, runs great, strong oil pressure. It is not down on power but not running hard due to the knock. Have had the valve cover off looking for anything obvious, everything looks sound. It’s not a tick, more of a knock. Have good oil pressure when warm. If it were a mechanical knock due to something breaking or broken I would think it would be constant no matter the temp. So I’m thinking oil temp related. Any help would be greatly appreciated.

dave

 

Assuming the valve train looks good, you most likely have bottom end damage (spun bearing most like). But it's still possible you have a valve issue. Take a video of the "knocking" and upload it. Have you tried listening to the knock with a long screwdriver or auto stethoscope?

If you have bottom-end damage, I would just slap in a rebuilt or used engine. You may not notice any serious issues now, but that could change fast. You might be looking at a simple valve issue though. My buddy has an 04 pathfinder (also a VQ35DE). It's had a valve tick since he purchased it. Still running strong without issue 3 years later. The tick hasn't gotten any better or worse.
-Icer

 

Thanks, I’ll try to upload a video.

 

Run thicker oil?

 

Will try thicker oil and also try to upload a video. Thanks for the replies.

 

You Tube

 

are all your butterfly bolts still there? mine fell out and was in the cylinder smashing about the butterfly plate was sitting ontop of the valve. this is on a VQ35DE out of an elgrand but i think they have the same intake in the 350z>? correct me if im wrong..

 

hm did you do the screw driver trick to listen to where is is coming from?

 

I did, definitely louder on the driver side of the block

 

Sorry asked the same question the other guy did.
From my experience its well worth ripping the top off to look at the cams and rule that out.
Like i said mine was tiny screws in the cylinder. If it is big end you may be able to polish the crank and put a new shell in but i dont see that as the issue unless its had wrong oil or poor servicing mixed with thrashing

 

I’ve had the valve cover off and did not see anything broken, loose, worn or binding with the cams or buckets

 

This intake is really specific to the Pathfinder or other VQ35DE chassis models. The 350Z intake is very different and doesn't suffer from the butterfly valve screw problem (common among that generation of pathfinders).
-Icer