So when I changed my oil, diff fluid, and plugs yesterday I made a terrible discovery. There was oil in the cylinder area where the spark plug sits. Not to much, but enough to raise an alarm. The only way I can see this happening is the gasket on the valve cover around the area is failing. It's only on two cylinders, 5&6. I'm just wondering if this issue is common, how alarmed I should be, and the difficulty of pulling th valve covers off. Looking at it I see it being about a 3-4 hour job with plenty of derp time included to make sure everything is right to replace the VC gaskets. Thoughts?

This is on an 04' sedan.

 

You're pretty much exactly right. The spark plug seals are molded into the valve covers, so you have to replace the whole valve cover (thanks Nissan!). It is a time-consuming job. If you are interested, there are companies that you can send your valve cover in and they will replace just the spark plug seals by redrilling holes and putting in their own - I have no experience with this, but you can search here for info. Would obviously require some downtime for your car.

The valve covers are very expensive parts, if you have not already looked it up yet.

Spark plug seals go all the time in cars with high mileage. The difference is whether you can buy spark plug seals individually ($4 apiece) or, thanks to Nissan, the whole valve cover at North of $250 apiece depending on where you get it. Find an OEM supplier rather than the Infiniti dealer, the 20-25% off really adds up on expensive parts like that.

Good luck. FYI, the passenger side is worse to do than the driver side.

 

I get it. The high mileage thing doesn't make sense though. My car just ticked over 66,000.

 

I forget what the warranty is on this, it is either 60k or 70k, someone will chime in. Maybe you will get lucky on that. LOL I have twice the mileage you do on my '03. Yours is insanely low, but good for you.

 

Powertrain warranty is 6 years/70K miles so OP you're out of luck there.

 

seems to be very common, and as long as it isnt alot its not going to affect you.

 

If you want to fix it yourself without replacing the entire valve cover read through this thread.

https://g35driver.com/forums/vendor-...lve-cover.html

Here's another DIY for replacing the cover.

https://g35driver.com/forums/g35-sed...placement.html

 

There is also this for a couple options, I wasn't able to access the above link so it is likely a duplicate
http://my350z.com/forum/engine/54492...ve-covers.html
https://g35driver.com/forums/g35-sed...follow-up.html

 

Ufff. This us gunna suck.

 

yea it does suck..mine have been leaking the whole time i've had my car and i haven't had any issues

 

I'v made this operation in mileage about 90k in Russia.
I bought original new valve covers, both, it's about 250 USD each.

But! I see this on changing spark plug in 80k mile, and replace on 90k.
So, all this time oil level was fine and engine works normally.

 

That's what I'm understanding. Replacing it is more of a "peace of mind" fix then something that is absolutely required. I figure when winter comes along and the car goes into storage I will have plenty of time to replace them. Should be safe until then.

 

Mine was leaky at 65k then gotta around to replacing the vc at 100k
Sparkplug driping with oil

 

 

YUUPP leaky valve cover over here too!! Two of my passenger side ones! lol but I have no problems with it yet. I got extended warranty so Im bringing it in soon. I found out when I changed my spark plugs.

MAKE SURE to clean up the oil in the spark plug area or else when you stick the coil pack back in they wont go in all the way with oil in there. Oil doesnt compress. If you push down on it and it pushes it back up still then theres still oil in there.