Hi All.
I'm new here, just got a 2005 Daytona Blue 350Z w 68k miles.
Something that I did not notice when I bought it was a knocking noise coming from the engine.
It still runs smooth and pulls hard so I'm wondering if it is normal for these engines to make that noise. If the fans are running or there is a lot of outside noise then you can't really hear it. But when it's quiet then you hear the knocking from inside and outside the car.
Any info would be greatly appreciated.
Thanks.

 

A knock is definitely not normal. You might want to have a mechanic take a look at your car.

 

^^ I agree; this is not normal and should be checked ASAP.

 

Yeah, will do. Thanks.
It's weird, only does it when hot, not cold.

 

Stupid question, does it disappear when you push in the clutch. Mine does this after it has been on a long drive. Sounds like a cement mixer with a brick occasionally thrown in. Push in the clutch it shuts up. Drives fine and everything.

 

That’s a clue…
Your engine lubricant becomes less thick after warm-up. Try changing the oil using a heavier grade.
--Spike

 

Change it with some 10w 30 or 0w 40. You probably have a bad cam follower.

 

I have an auto but yours sounds like the throw out bearing for the clutch.


I'm taking it in this week to get checked but I will try the thicker oil too.
Thanks for the help guys!

 

Yeah mine is one hundred percent clutch related but I've grown use to the chatter. The only when hot threw the flag of maybe you had the same problem. But good luck with at the shop.

 

When i purchased my 05z, it was the engine bearings going out. Mine still pulled hard until the very end. Check is sooner rather than later.

 

Yeah, everyone's TOB started to sound like crap after about 500 miles from new. I think I got 300 miles out of mine when it started making noise. Nissan went so far as to tell its techs that the noise was "normal"

 

Unfortunately, the TOB noise is "normal", since it's not an actual TOB "problem". It's a bit of slop that develops in the linkage and on the shaft. It's common in all vehicles that do not have a shaft mounted slave.

Bk88, I would love a video of this engine knock, it makes the guessing game a lot easier.

 

Could be TOB, clutch, something by the fire wall tapping, valves, exhaust leak ( bad one if it is lol) transmission, loose bolt somewhere, extremely bad piston slap ( doubt it cause its still running), bearing on its way out, loose cam shift ( have seen it before believe it or not) exhaust bolt etc... The list goes on and on. Move your head around the top of the engine while bumping the revs up to 2000rpm to pin point the location of the sound. If it is engine knock and it's about to blow then you'll hear the knocking coming from the bottom of the engine. Trust me you'll know if it's engine knock once you rev it close to 2k cause it'll be the worst metallic rattle/knocking noise it can make ( not loud just distinctive ). If it is then shut it off and tow it to a shop for repair. Unless you wanna do it yourself

 

All of your good points (and you make good points here) reinforce myfirstzcar’s request for a recording of the “knocking noise.”

I think we all agree if it is a true knock, the engine might be shot, even with an immediate tow (and no engine running).

--Spike

 

Hes right unfortunately. Sorry for the bad grammar btw. I was in a hurry earlier today at my job. Military keeps me running around all day lol

 

to the OP:
My car had the same issue, an engine knock sound that went away after warming up. took it to a local tuning shop that specializes in Z's, they couldn't find anything wrong with the car mechanically, but they told me to put 10W40, which I immediately did. after doing that the noise was virtually gone! hope this helps!

EDIT: yesterday I went back to the shop. figured out exactly why this noise was happening to my car- it's burning oul around the piston rings. so once again changed the oil but this time put 5W40, added lucas oil pure synthetic oil stabilizer, and the noise is fully gone. one quick check for this would be to look at your idle oil psi (after engin has ran for at least 5 minutes) should be about 15psi. at 2000rpm it should be about 45psi. if it's lower, then check your oil level. if you're low on oil then you're either leaking or burning it. top it off and the noise should quiet up or cease completely. again, hope it helps.

 

Thanks for all the info guys.
I'll try to record the sound soon but have an appointment with a shop this Saturday.
Will keep u posted with the results.

 

Good luck! Sounds like the previous owner might have known about this issue and sold it.

 

So does that mean that the aftermarket clutch kits (i.e., Jim Wolf) won't resolve the TOB rattle simply due to its French design?

 

Bonjour, unfortunately the only thing that might eliminate the noise would be swapping to an internal slave, which I don't think is possible.