New user question - timing chain a concern?

[georgy_d28]

Hello,

I have been a stalker of this forum for the better part of a year since I bought my repo 2007 M35. 112k miles, but with a replaced 82k mile engine, new radiator and cooling fan assembly... all before i bought it.

This is my FIRST Nissan product EVER.

I have had 7 Honda/Acura products since 16 and they have served me amazingly, even with the transmission debacles of the early 2k's

I have done a fair amount of research and have seen common failure points and will address those as needed, but here is where I seem to be at a loss.

I know the the timing chain tension guides fail, understood, but they only seem to produce knocking noises and I think my situation is a little unique/ maybe not please advise.

when the car is warming up above 75 plus degrees it is quiet and normal, but when the cold start temp is below that it seems like there is a louder "running" noise from the top front of the timing chain area. almost like a bad engine mount, (but without any excess movement when tested) when heard from inside the car.

when the car is below 35 or so degrees the engine is significantly louder inside the car and around the top of the engine, but completely DISAPPEARS when engine is at least 1/4 operating temp, not to return until the car has completely chilled all night. I have opened the tension-er inspection cover and it is still intact and the water pump side is not loose either.

sounds ridiculous but should i just plan on a timing chain soon? To be honest I'm not shy of an engine but haven't seen anything like my symtoms, hopefully one of the great minds here can help me..

Thanks so much

Eddie

[EdBwoy]

I know when Nissan first came out with the VQ35, most of them had timing guide issues, especially in the FWD applications. I can't remember of any complaints about timing chain rattle on the Pathfinders of that era, nor have I come across any complaints in the G35s that came out - my assumption was that their longitudinally mounted engines got special treatment and got good timing guides.
Secondly, with time they improved the designs of the timing guides and by 2006 I don't think (m)any FWDs had rattling timing chains any more.

On a relatable note, every Nissan I have ever owned has lifter tick on a cold start. My Maximas & i35s had it, the Qx4s have it, Q45 had it, M45s have it... and especially my 06 M45 has a very annoying-to-me tick/tap at startup. It is just as you describe, more pronounced at the top of the engine and mostly goes away when the engine warms up.

Not saying you should totally ignore this if you feel like yours is a bigger issue, but dealing with noises that would have previously made me uncomfortable at startup has been part of my Nissan experience.
Surprisingly enough not many people around me notice these things. I HEAR and SMELL EVERYTHING, so if I'm unsure if I'm tripping I just ask my passengers if they hear or smell anything new.

[Ilya]

Hi there, I agree with EdBoy (he's one of our more knowledgeable members BTW). Also, I updated your thread title so it's serves a slightly better purpose for search purposes, etc.

[EdBwoy]

Hi there, I agree with EdBoy (he's one of our more knowledgeable members BTW). Also, I updated your thread title so it's serves a slightly better purpose for search purposes, etc.

Thanks for the kind words IlyaKol.

[Mgran]

EDboy, Have you tried any of the various oil additives to quiet the noise? Do you think it is an issue with the variable valve timing mechanism? I asked the service rep at Sacramento Infiniti and he said, they do that from time to time after sitting for a few days. I can't help but think those loud noises are harmful. Mine is a 2008 M45 and it has done the rattle about four times, the rattle is accompanied with some smoke and a bad smell, is that consistent with your experiences?

[EdBwoy]

Well, in all all the other Nissans I had, I really did not do anything about it. I think the valve lifter designs on most Nissans are such that they give good performance, but sacrifice in the noise-at-cold-startup department.
However, this 06 M45 that I was talking about ended up throwing a rod "suddenly". I put that in quotes because this engine, like many I had, made some noise when cold. Looking back at the videos I recorded, it seems like I should have caught this earlier on.

As you could imagine, with gravity, engines will drain their oil to the lower compartment. Let them sit for too long and the upper compartments are sort of "dry". To me, this explains why our engines make such a racket at startup if they've been sitting too long.
The second part (and I really have to study the oil path to confirm this theory) is due to oil draining from the top and pooling in the cylinders. After a long hiatus, it means your initial combustion includes a decent amount of oil to cause your blue smoke.

Here's a catch. The V8s in the 06+ M45s as well as some Fx45s seem to have oil issues. These lead to rod bearing issues and make a different kind of sound than lifter tick. I have a lot of youtube videos and forum threads that I have been referring to when trying to diagnose these issues, as well as 2 personal incidences of damaged engines.

Concise answer: No, I haven't tried oil additives to cure the noise, but I have used seafoam to get rid of carbon build up. If you can, post a video of your engine exhibiting the noise and we can do our best to tell you if you should be concerned.
Also, give us some history on the car.