Start up noise

[Kestral]

Strart up rattle or noise seems to be common on the VQ40DE V6 in Nissan Pathfinders, Frontier trucks and Xtera's. I noticed it a few times when it was cold out on my new to me PF at startup and over on the Frontier forum this seems to be quite common. Some say it is piston slap some say its the timing chain and others say its rod knock? I don't think its a rod knock I had a car with a rod knock and lets just say it was quite different. Although this seems common on the V6 many notice it since birth through many miles many have well over 200K so the noise does not seem to effect anything? anyway I just thought I would comment on it. How may of you notice a start up rattle or quick noise before your oil pressure comes up?

[JAHBLESSINGS]

common issue. all cars have that noise until oil reaches the head. some louder than others.

[skinny2]

I have it and have had it for quite a long time. Mine sounds kind of like a plastic noise for just a second or so and only does it after sitting overnight. Reminds me of sticking something in a fan.

[eieio]

I wouldn't think piston slap or rod knock would have anything to do with it
Those are symptoms of older, worn engines
Modern engines have very close tolerances

[slavabon]

Short 1-second rattle on cold start can be fixed by switching o better quality oil filter. The cause for this is your oil draining back from the system. Also, I don't consider OEM oil filters - best quality filters. Some of them Will cause this. Put a Bosch or K&n or equivalent and the rattle should go away. Had this tested several times on 06 Xterra and 2 pathfinders I have owned in the past several years.
The piston slap or prolonged engine rattle that goes away after a few minutes or until the engine warms up is somewhat common in VQ40, at least according to the forums. I think it really depends on how anal you are about noises. Most people don't notice it, but this slight cold engine tapping noise on my 2010 used to drive me nuts, but I can also hear faint piston slap in some new Toyotas idling in the parking lots . Then I started using 5w-40 Shell Rotella synthetic oil (its a bit thicker) and things got better.

[Kestral]

Short 1-second rattle on cold start can be fixed by switching o better quality oil filter. The cause for this is your oil draining back from the system. Also, I don't consider OEM oil filters - best quality filters. Some of them Will cause this. Put a Bosch or K&n or equivalent and the rattle should go away. Had this tested several times on 06 Xterra and 2 pathfinders I have owned in the past several years.
The piston slap or prolonged engine rattle that goes away after a few minutes or until the engine warms up is somewhat common in VQ40, at least according to the forums. I think it really depends on how anal you are about noises. Most people don't notice it, but this slight cold engine tapping noise on my 2010 used to drive me nuts, but I can also hear faint piston slap in some new Toyotas idling in the parking lots . Then I started using 5w-40 Shell Rotella synthetic oil (its a bit thicker) and things got better.

I have used Shell 5w40 Rotella synthetic in several vehicles with great success and would probably use it in my 2012 PF if the warranty did not specify 5w30 grade oil. I have just 8,000 miles on the truck now but after the warranty expires I will probably make the switch.

[volvite]

I used to own a 2006 Mazdaspeed6 and the only oil I used and other members of the many car forums used was the 5W-40 Rotella. It worked wonders in that car. I've yet to use it in my Pathfinder as it seems that the Mobil-1 I use works fine. However if others have had success with the Rotella in their Pathfinders I'm ok switching.