Okay, so the engine startup rattle / timing chain noise looks to be common for nissan/VQ motors. Having the dealer fix this looks to be more work than what it's actually worth, since it seems like you can live with this sound as long as it's only for a second or 2.

Now, has anyone looked into or installed an engine pre-oiler to alleviate this issue? If so did it work? It doesn't seem that difficult to install, plus it could be better overall for engine wear.

Here's a link to a discontinued version of it just to take a look at one:

http://www.smartsynthetics.com/produ...mk01-amk02.htm


Another:
http://www.engineprelube.com/


I'm sure there are other brands out there.

 

totally in for details on this.

 

That's one of the few modifications that really makes sense, and the cost is reasonable.

Since it's the oil system (the lifeblood of the engine), be sure everything in the kit looks top notch and goes together like it should.

 

From my understanding, the reason the timing chain rattles is because lack of oil pressure to the tensioner...Not necessary lack of lubrication...

 

oh so this actually creates OP before you start the car...not just like a cam spray bar or something...my mistake


This is interesting...hmmm

 

http://www.automotoroiler.com/order_now.html

229 shipped. easy to install as a catch can to be honest.

 

The timing chain tensioner is made so it doesn't go completely loose when the engine is shut off. It just goes back to the last notch on the ratchet in the tensioner. If your chain is making noise at startup, it may be worn beyond what the tensioner is designed to accommodate, and it's time for a new chain.

 

I refuse to believe a timing chain would wear out at 29K miles. A timing belt shouldn't even do that, the tensioner is ****, other than that nissan did an amazing job with our motors.

 

my new built motor also has timing chain noise at startup for the 1st 2 seconds at a cold start. I've also been looking into oil accumulators. This one is cheaper than the one sold at summit.

once I pull my meth tank off, i have a perfect spot to fit the larger oil tank. might try this to get rid of that noise. dont wanna pull the motor again.

 

Ouch, just had the motor out too that sucks, but keep us updated! Let us know if the noise permanently goes away.

 

I have a pretty good ear, so I hear all the usual VQ-DE start up noises that have been pointed out to me by knowledgeable Z owners and mechanics. If the oil pressure has drained from the timing chain tensioner unit it will make a single soft clack sound as oil pressure refills it. If you are hearing a pronounced rattling sound on a cold startup, (that lasts for a half second or so) it is most likely a variable cam-timing sprocket on one of the intake cams. This is not an oil pressure issue, but simply the sprocket re-indexing itself every now and then on a cold start.

There is a Nissan TSB that describes this and how to replace the offending sprocket. As far as I know nothing actually breaks down if you don’t replace the part. If you want I’ll track down a link to the TSB when my boss stops yelling at me.

 

^ya, its more along the lines of the VCT sprocket

 

To me, a cold start means low oil pressure. If the VCT sprocket is the culprit and it's not an oil pressure issue, then it would make the sound all the time the car is started, cold or hot, wouldn't it? This sound only appears at a cold start once the oil-pressure is drained out. Also, the sound goes away the instant the oil pressure light dissapears as well. (im assuming this is the same time that the tensioner extends out from the pressure to tighten the slack on the chain).

The extra slack would be the chain dragging along something until the tensioner extends the arm against the chain, tightening the slack.

http://carphotos.cardomain.com/ride_...0078_large.jpg

 

Couldn’t find the 350Z TSB, but here is one for an older Maxima that is basically the same. http://maxima.theowensfamily.com/tsb/ntb03-060.pdf

This is common on VQ engines with most people reporting that it will make this sound the odd time. However it will only happen on a cold engine start up. Once every week or so, my 04 Z will make this noise on the first start up in the morning.

 

in for updates

 

I would pick up a pre-oiler and try it if I wasn't saving for ART pipes and Osiris. Plus, if this is something that may or may not fix it then I'm not ready to take a hit for it yet. But, not sure if anyone would already have a pre-oiler lying around that could give this a shot, maybe from an old car (old muscle car people seem to use these more often). Anyone else with the start-up rattle wanting to give this a go?

 

Modified Mag did something similar to this on their time attack S2000... It's an Accusump:

http://www.accusump.com/

I'm personally looking into this particular unit.

 

Not on my Z, but I have them on my boat. The type I installed hook-up to the fitting for the drain plug. When you want to change your oil, there's a quick disconnect and youump the oil into empty jugs. These are the aircraft type. They work like a charm! It's the red pump next to the exhaust header.

 

A pump-type pre-oiler is quite different from an accumulator with a solenoid valve.

It sounds like you pump is getting oil from the drain plug fitting, then putting it into the oil system. Does it go through the filter before going into the engine?

The accumulator stores filtered oil under pressure, and releases it into the system when the ignition is turned on. That seems simpler, and simpler seems better.

How does the cost of the pump system compare to the accumulator? I'm thinking it's probably twice as much if it's using quality components. What added benefit do you see with the pump?

 

Looking around on the eenternetz, it looks like the rattle is common among all different types of cars, not just nissans. Some people have installed pre-oilers and it fixed it along with any other startup noises...

Originally Posted by SlingshotSEO
I have a slight engine knock and I'm wondering if it relates to this timing issue. I have a 2005 Xterra with about 32k miles on it. I noticed the extremely high rev at startup when I first purchased my Xterra. Will this end up shortening the engine life?
I talked to the dealer about the high rev on start up, he said there is nothing to fix it. I added a pre-oiler so at least it won't start dry. I don't hear the knocking sound I used to after adding it, but I need to find a bottle larger than 20 oz. to store the oil.