I can't answer that question, but I'm sure somebody on here probably has a few ideas.

 

Well.. found oil in the well closest to the driver. Made an appointment with Beshoff for them to look at it. 69350miles on the odo!

 

I just bought my 2005 G35 manual sedan this summer and while researching (read: lurking) on here I found out about this issue. I decided to change my spark plugs early just to check for the oil leak. Sure enough I had it on cylinder 6 and didnt check anything beyond that. I have about 69,000 miles on the car so I took it to the dealership and they're going to replace both valve covers under warranty.

If anyone hasn't checked for this yet I highly suggest you do. My dealership quoted me at around $1100 to replace both sides.

 

I have an early 2003 G35 sedan with slightly over 90,000 miles on the clock. Oil consumption has never been a problem and the car still runs great. I have been taking care of business with the recommended 90K services. Full AT oil flush, new belts, new hoses, new coolant. I have owned the car since new and since 7000 miles the engine has been lubricated with 5w-30 long life Mobil 1 engine oil, which gets changed every 5000 miles. Between changes, oil usage is less than one quart.

Today I went to change my original plugs for NGK Iridiums and found a fair quantity of oil in the spark plug tubes for cylinders 3, 5, and 6. The spark plugs had never been removed before, so this was my first look at the oil leakage issue.

The oil went down into the cylinder the instant I removed each plug. As I replaced each plug, I cleaned up the oil residue as best I could and installed the new plugs. Upon start, the engine fired immediately and smoked for a couple of minutes. The car runs perfectly normally; maybe even a little better than before, but that could be my imagination.

If time and money were no object, I would have the dealer replace the valve covers/gaskets to make it perfect again. I'm just not sure this is justified. Based on all of the reports on the forum, I'm pretty darn sure that the oil leakage has been going on for quite a while, with no detrimental effect that I can detect.

Seems to me that while the engine is running that there is a very small oil leakage which is passing from the inside of the valve cover to the spark plug tubes. When the engine is shut down, there is no oil standing in the galleys on top of the cylinder heads, so the oil in the tubes may leak back down to the cylinder heads, and drain into the sump. In all likelihood, this has been going on for a very long time, and my G35 engine has never missed a beat due to a spark arcing across an oil-wetted spark plug electrode.

I think I will just continue to drive the car, exactly like I did before I was aware of the oil level in three of my spark plug tubes. If the engine ever misses a beat, then we can talk about replacing the cam coversand associated gaskets.

 

I just changed the plugs on my 04 with 106K miles. Pretty much the same as others, found some oil. driver side rear had the most oil in it. Surprisingly my old plugs looked pretty good. After installing the new ones the car fired right up, I didnt notice any smoke. Took it for test drive and can feel a minor increase in acceleration. Everything else feels normal.

 

Oil won't leak down past the plugs. Believe me, it accumulates. Consider the pressure working against the threaded hole for a spark plug during combustion, the oil has nowhere to go. So, other than some reduction due to heat over time, whatever you find is pretty much what's there. That's why you won't see oil level drop, once the tube is full, it's full until you drain it. This is usually a very, very slow leak.

 

Look at the motor...spark plug sits down in a tube that allows it to reach down into the combustion chamber, the seals sit on top of that metal tube:



The oil forces its way between the top of that tube and the VC seals.

 

found one of my valve cover leaking by the dip stick. should I have the dealer replace one or both of the valve covers / gaskets?

 

I decided to check it as well.

Here is what I found in #6

 

How many miles?

 

56k miles

 

Just in case anyone needs a passenger side valve cover I am selling one on Ebay and it ends in two hours. Only at $.06 so far so you will get a good deal. It is used and I just never installed it before I sold my G last week for an Xterra.
http://cgi.ebay.com/ebaymotors/ws/eB...%3AMESELX%3AIT

 

Early 2003 G35 sedan here and changed my original plugs yesterday per the schedule. Cylinder #6 tube had a lot of oil in it. The coil shaft, inner spring, and boots were completely saturated - I disassembled everything and dried it out. All other cylinders spark plug tubes were bone dry.

The oil drained into the cylinder when I pulled the old plug and I simply put a new plug in. I had no issues with misfires and the old plug was not oil fouled so I'm just going to drive it. No way am I spending $500+ to have this fixed unless it starts to cause driveability issue or oil consumption (leakage) gets much worse.

I do occasionally get a smalll puff of smoke after startup and consume about 1/2 quart of oil every 4000 miles so now I understand why. Upon startup after the plug change the car bellowed white smoke for a minute after all of the oil that drained into cylinder #5 burned off.


Brian

 

taking my car in on tuesday, i just bought an 06 in august. i havent checked the valves yet, not confident in my skills yet to take somethin out like this. hopefully they ll check for me

 

wow there are soooo many of us with this issue i am not sure why there has not been a recall yet but i am hoping my dealer will change mine under warranty i got it with 67,000 and i have 69,000 now but it has manufacture date of 03/04 so it may be past the time for powertrain W. If not will have to get the parts and DIY cuz i ain't paying the stealership labour that i cud do myself. Just it will be getting cold to do work outside soon.
Love this G to death but man she is costing me a bundle i think i will have to do the unthinkable and switch to BMW or Merc they have problems too but they take care of them not deny it like infinity does and leave you in the deep