Clickity clack noise

[energysound]

I have a 2001 QX-4 makes a clicky sound, when you rev it up it gets worse. It has always done it at start up for a few secs but has always gone away quickly. After a little research this seemed to be normal at start but now it does not go away. Did some digging around on the Internet and from what I could tell the majority of folks pointed to a stretched timing chain or weak tensioner. So I replaced the timing chains and all three tensioners. Timing was off one tooth on the passenger side head.I got it all reassembled last week and it started right up but the noise is still there. I am hoping it has not bent a valve or anything. I have read a bunch of threads here today and saw the one about the screws coming loose on the rail in the intake, one of my screws was missing, I got a screw & locktighted it in. Checked the rest they were all still tight. I will go through and lock tight all of them after reading about them coming loose. How can I tell if that screw has killed my motor? Any way to check without pulling the head off ?? I pulled it back down to the timing cover last weekend but have stopped to do a little more research before I take it down to the head. Any feedback or suggestions will be appreciated.

[Towncivilian]

Unfortunate that you were affected by a power valve screw coming loose. I would call 1-800-NISSAN1 and see if Nissan will do anything at all about it. It might be impossible to tell the extent of any damage without a tear down. I'm not sure what the noise could indicate. Could you upload a video of it, perhaps? Definitely apply red threadlocker to the remainder of the power valve screws. Does your QX4 burn oil?

Welcome to NICO. I wish your welcome were under better circumstances. I deleted your other duplicate post.

[fleurys]

i guess if you are lucky, it means the screw is still in the cylinder chamber and has not passed yet through an exhaust valve.. If I were you, I would take a magnet on a stick and remove each sparkplug , one at a time, and see if I could pick it up like this... Just a thought... The other reason I know about a tick noise is when the truck is low on oil...(but Ithink this was with the 3.3, not the 3.5)...still worth a look...

If you engine is not taking oil, then the screw has not killed your engine yet... but you can be sure that if it goes through a valve port then it will most certainly do some damage.... go get a magnet fast...and don't use it until you know for sure nothing is in there....

S.

[Alfredo24.pr]

I have a 2001 QX-4 makes a clicky sound, when you rev it up it gets worse. It has always done it at start up for a few secs but has always gone away quickly. After a little research this seemed to be normal at start but now it does not go away. Did some digging around on the Internet and from what I could tell the majority of folks pointed to a stretched timing chain or weak tensioner. So I replaced the timing chains and all three tensioners. Timing was off one tooth on the passenger side head.I got it all reassembled last week and it started right up but the noise is still there. I am hoping it has not bent a valve or anything. I have read a bunch of threads here today and saw the one about the screws coming loose on the rail in the intake, one of my screws was missing, I got a screw & locktighted it in. Checked the rest they were all still tight. I will go through and lock tight all of them after reading about them coming loose. How can I tell if that screw has killed my motor? Any way to check without pulling the head off ?? I pulled it back down to the timing cover last weekend but have stopped to do a little more research before I take it down to the head. Any feedback or suggestions will be appreciated.

loose wheel lug nuts perhaps?

[CanuckQx4]

loose lugs causing a startup noise that quickly goes away??? .... cmon

Sounds like a power valve screw to me

[Alfredo24.pr]

loose lugs causing a startup noise that quickly goes away??? .... cmon

Sounds like a power valve screw to me

lol it could happen

didnt read that part right

[energysound]

Nope not a lug nut. It is parked wheels chocked & not going anywhere. I will check the cylinder. I will see what manifold runner was missing the screw & look into removing that plug & see what I can tell from there. Maybe I can find a buddy with a borescope & see if I can see into the cylinder through the plug hole. It can only go straight down the intake runner into that cylinderif I am asuuming correctly. only one place to go. No it hasn't used oil about 1/2 quart between oil changes at 5k miles. I will go Investigate. Get back to ya all later, Thanks so far for the help.

[Towncivilian]

1/2 quart per 5k miles is acceptable oil consumption. Good luck in your search for the screw.

[energysound]

Well I didn't see anything telling yet. Pulled out center plug & tried to look down hole to cylinder. Didn't see any apparent damage but I cant see very far down the cylinder. plus it is too cold out to operate well. It's around 40 out there. I am going to need to spin the piston down to the bottom of the stroke & get a better look around in there.