I recently purchased an 03 with top end noise. Pretty noisy on first start up but quiets down once everything gets oil to it. I’ve gone through top end on gm motors, and plan to LS swap this one some day. Originally planned to right away, because the kid I bought it from thought it was a rod knock but it’s definitely not that and in the top end, so I think I’ll fix it and drive it as is for a while.
That being said I’m just looking for some good resources on top end work for these motors as I’m not familiar with them like gm engines. I’ve got a haynes manual coming, and just looking to do my homework before I tear into it. If anyone has any suggestions or good resources I’d greatly appreciate it.

 

Factory Service Manual!

This is what I use for anything extensive.

http://www.nicoclub.com/FSM/350Z/

This guy is pretty good too. I've been watching his vids for when I decide to do a complete teardown

https://youtu.be/DtVD2SZu7Vs

Just follow the parts from the first vid

 

aside from the noise coming from the top end what other tells do you have that it's not rod-knock?

Do you have a video of the noise?

Have you changed the oil recently? see what's in the oil or filter? You could do an oil analysis to further track the problem if you wanted.

The factory service manual is pretty good as long as you have engine building back-ground.

 

Betting it is the infamous VQ valve / lifter tick

 

oh yea … it always is.

I always listen for consistency in the chirps where a spun bearing will be inconsistent.

 

I literally just got the car home late Sunday night, and it needs a battery so I haven’t messed with it much yet.
I’ll get a video maybe this weekend, I’m not claiming to be an expert, I’m only 29 and have limited experience but just my opinion and a couple other mechanics that I know agree it’s in the top end, it quiets down a few seconds after start up and everything gets oil, and you can hear it best on the left side if you get your head right over the intake there.
i plan to put some Lucas in the oil and run it a little to see what that does. Won’t be out much if it doesn’t quiet it down any.
I’ve watched a few videos that others have posted of valve/lifter ticks and it sounds the same to me as well.

 

I don't know either based off the info and I too am hardly an expert. But it could be valve tick it could be a rod bearing going out.

Is the noise consistent with respect to engine speed? meaning does the tick increase in frequency as engine speed increase? or is it all over the spectrum of ticks?

having the sound settle after start-up could indicate rod-knock … as the oil pump has established oil pressure and it's filling in the oil clearances.

I don't know if valve tick gets better or worse after warm-up...

post a video and there are some very smart and experienced people on the forum all who would off you their 2cents.

congrats on the purchase btw

 

I’ll get a video this weekend. I haven’t really rev’d it up or ran it much. Trying not to hurt it any worse if it is in fact top end and easier repair.
If all else fails I’ll go back to my plan of an ls swap, although it would be fun to drive it for now.
im in the middle of redoing a 48 Chevy pickup with an ls motor, so I’m hoping to get it done before swapping the z

 

Valve tick does get quieter as the car warms and does increase with RPMs. I assume it gets quieter after startup once oil begins to fill in the clearances similar to what you mentioned with the rod knock. Mine has had the tick since I bought the car 8 years ago, at only 46k miles. No problems almost 100k miles later.

 

Finally got a video. After running the car a little more it may indeed be a rod knock. Didnt have anyone to run throttle for me in video so it’s just idling, but sometimes when getting out of the throttle the noise goes away completely. It does increase in frequency when revved up.

 

I cant say … that sounds pretty consistent … here's my rod-knock from last year:

 

So what says you, Beall? It's definitely not valve/lifter tick. Sounds like something much more detrimental.

OP, I'd really suggest taking it to a quality mechanic to have it checked. I'd hate to say it, but start setting money aside in case you need a new motor.

You could always DD the new one, follow Bealljk's thread, and build rebuild this one into a monster!

 

I'm saying it very-well could be abnormal valve lifter / valve train noise ... sounds too consistent to be a rod (from what I can hear).

But yea, take it to a mechanic for a formal diagnosis.

lol - It's coming along! Thank you for the kind words!

 

Well I certainly don’t want to sink much money into this motor, my whole plan all along has been to LS swap it with around 5-600 hp.
im in the middle of redoing a 48 Chevy pickup with an Ls1 though, so most of my funds are going towards that right now.
i May tear into it this winter and see what the problem is, and see where I’m at with the 48 and decide if I want to rebuild the v6 or just yank it out and prepare for the LS motor.

 

Fair enough. Good luck with whichever direction you choose to go. I don't think you'll regret an LS.