I just ordered two new covers because i did not want to do a ghetto job and just drill my seal out and put a new one. I am replacing both, is that a good idea? one of them is not leaking at all but the other leaked a lot into one spark plug.

 

Yup. Good job. Replacing both is the way to go

 

You don't need to replace both, but you might as wel since you are there with the tools already doing the other one. Won't add much time to your project and it would suck if the other one started leaking 3 months later and you have to do the job all over again when you could have just gotten it done now

 

How does one see this problem without taking apart the spark plugs? Are there any symptoms, does the car act in any specific way? Usual locations? Any way to spot this just bu looking with a flashlight?

 

You don't need ot take out the spark plugs, just remove the coils and peer down the spark plug tubes

 

Also no symptoms, take your the coil and see if it's soaked in oil. If there's too much you might get a misfire. My car was fine but the oil leak can't be good for it. Can anyone tell me what the ultra grey is for/ where to put it? Thanks

 

You can dab a little of the ultra grey on the corners of the VC gasket.

I should look into mines now that i'm at 106k, i did plugs at 90k and it was dry. I know its not an IF but a WHEN these covers are going to go.

 

I had found the leak at 110,000 miles while replacing spark plugs. I cleaned all oil but didn't fix it. Some years later at 160,000miles, I checked it again but it wasn't that bad. We can live with them together. lol.

 

Just changed my plugs at 99000 on a 05 and it PS closest to the firewall was filled.

 

You don't need ot take out the spark plugs

 

Bumping this thread again. After speaking to a few G35 owners here at a local meet, there were a few who have not had this problem despite there cars having over 100K+ km. These owners all had the same thing in common after I ask them about their oil, they all used conventional 5w-30 either DIY or just regular dealer service bulk oil. Could there be a correlation with using synthetic oil and having these leaky gaskets? I was planning in making the switch to synthetic but now I'm not so sure. Can anyone provide some insight?

 

I have been running synthetic oil since I bought my car 5 years ago. Two different engines, one at 150k one at 30k. Neither had leaky spark plug well seals... I don't think synthetic oil is the main cause.

 

My car at 172K miles does not have leaky seals. I've run nothing but Castrol GTX 5w-30 conventional since it was new.

No idea if that's the reason but just more info for you.

 

I tried to call R & D Factory (909-287-3511). I was told that they are out of business. Any info where to get the seals? Is the seal for Nissan 350 z the same seal for the Infiniti G35? For example: http://www.partsgeek.com/qc37y5n-nis...+Tube+Seal+Set

 

Yes it is but don't do that its super sketchy. You need to drill the old ones out and use some liquid gasket and ****. Its much better to replace the valve covers for 400~ you can do spark plugs and plenum spacer or whatever else on the way.