Unique need for my VQ, burning, squawking

[aualtima3.5]

What's up guys, haven't been here in about six months. It's feels right to be back.

My Nissan has a unique problem: timing chain rattle not only at startup, but also at about 2k rpms and coming down on revs.

It gets worse as the car gets hotter. It isn't audible in the first 5-10 minutes of driving. Theory: Oil gets thin and can't pressurize tensioner.

Here's how I have been bandaiding this problem: thick oil!
Castrol 0w30 for about 10k, but used way too much oil.
Now using M1 0w40. About 1/2 of GC consumption.

Does anyone have a suggestion for a good oil? The M1 got rid of the startup rattle (95%), but the rattle during driving is still there. I know this is a mechanical problem, but I don't have the cash to fix it now. I have a feeling a slightly thicker oil at op. temp will fix the rattle, but I don't want to go to a 50w.

 

[aquariuscsm]

What kind of Nissan do you have? There`s some posts on this very subject on MY350Z.COM

 

[mcrn]

My guess would be he has an Altima.

 

[mechtech2]

Use the thicker oil until you dive in and get those parts fixed.
Start planning and getting parts now, because it's in your future.

 

[aualtima3.5]

So any oil suggestions? Have I run out the options? I would to stay synthetic since I do ALOT of short trips (3mi one way)

 

[02zx9r]

Dino's can handle short trips as well. I am not to sure which are the thicker dino oils but I thought I read that maxlife was a thicker oil. Could be wrong

 

[tntt]

I have similar issues w/ my 02 V6 altima. I very seldom get that timing chain rattling sound at start up and when it happens, it's only a couple of seconds. However, I get that rattling sound after the car has warmed up. It usually happens after 15 minutes of driving and at 1,800 to 2,000 rpm. The rattling sound happened all through out summer and fall but have not have any issues this winter. I thought this was pinging and I've brought it to Nissan. They could not find anything wrong. They said that I try switching gas brands (I've always used premium) but that didn't help. I've been using Shell, Sunoco 94, and Petro-Canada which are all top tier brands. The speed shop I brought this to said it was definitely not detonation but was not able to diagnose exactly what it is.

I'm also burning some oil and have tried Amsoil and GC. I also do a lot of short drives, 15 - 20 minutes to work.

There have been a number of possible solutions discussed at Nissanclub.com. As I recall these are:

1. A loose heatshield - I've done this and seemed to reduce the rattling sound but not completely eliminated

2. There was the issue of something like a cam gear (not quite familiar w/ this part) needing replacement.

3. In our y pipe (exhaust) right after the flex pipe, there's a metal part/collar that can break and it also rattles. (haven't checked this)

4. Using regular gas (VQs prefer premium gas) - I have a more pronounced rattle/ping w/ regular gas

5. There were several who said that blow by gases go through the pcv valve and a fair amount of oil is collected in the lower intake manifold. They said something like this the oil in the manifold gets burned by the engine but can also cause the pinging in the process as it lowers the octane of the fuel being burned. - I haven't checked my intake manifold but this has been discussed at the maxima, 350z and g35 forums. They've installed DIY catch cans b/w the pcv valve and the intake manifold.

6. Low oil level seems to cause the rattle as well in my experience. - Now, I keep my level at the full mark.

7. Another issue w/the vq is that oil gets into our spark plugs through the seals in our head cover. You'll have to replace the whole head cover. I haven't checked mine recently but last summer, i had my spark plugs replaced and I was told they were clean.

8. I've had my pcv valve replaced and I was told it was plugged. However, I was still have some oil burning issue.

9. The last thing is that it could be the pre-cats. I'm hoping that this will not be the case. There have been lots of cases of damaged pre-cats (which may cause the rattle) and particles get sucked in and destroys the motor. This has been a known issue for the QR 25 engine but there have been a lot of VQ35De affected by this as well.

Currently, I'm running auto-rx hoping that it will clean my engine and reduce the oil burning. I do not know yet if my rattling issue will come back when the weather gets warmer. So far, I do not have any pinging/rattling sound but it's still very cold here in Canada. I still have some oil issues but I'm just in the middle of the cleaning phase.

I hope this helps. Good luck.

 

[aualtima3.5]

TNTT: you have a pm.

 

[ThirdeYe]

My old altima's timing chain used to rattle a little bit when it would drop below 1,500 rpms, I was told it needed a new timing belt tensioner but the labor was over $400 to have it done, so I just held off and it never gave me any problems aside from the annoying sound. But I wouldn't recommend putting it off like I did, I was very naive at the time

 

[tntt]

Thanks AuAltima, sent you a reply