G35 valve cover replacement

[mb32]

I have oil leaking into the plug wells on my 2006 G35 which requires complete replacement of the valve covers, due to non-serviceable plug well seals.

Has anyone installed aftermarket covers and gaskets? Rock Auto has ITM covers for less than OEM covers, but I have never heard of this brand before.

Is it advisable to replace the plenum gaskets at the same time when the intake is removed?

 

[bowlofturtle]

I've heard most non-oem covers end up leaking after 1 year or so. Most people who post up getting non-oem post about no leaks after a month or so. But rarely see long term reviews.

$100 non-oem plastic ones VS $300ish OEM ones. All because nissan didn't make servicable spark plug tube seals.

I need to do my covers as well, Normaly driver side rear cylinder with a little pool of oil.

 

[FlyNavyP3]

ITM makes nice stuff, they're an import only company focused at OE quality replacement parts, or at least they used to be when I sold their parts 15 years ago.

 

[ctechbob]

https://g35driver.com/forums/engine...-cover-write-campaign-8.html#post5772720

Well, there's always that option.

Not sure what Nissan was thinking with that design. I've never known a tube seal to not leak over time, on any brand.

 

[mb32]

I ordered the ITM covers but will order factory OEM cover gaskets as well. Not worth taking the chance of having to do the job again with cover gaskets that leak shortly afterwards. Found a few posts about that happening. Didn't seem like there was much concern with using aftermarket covers. Mine are 13 years old and don't leak, it is only the inner plug well seals that are the problem.

Will also change out the plenum gaskets just for good measure while everything is apart.

 

[The Critic]

We have purchased a few sets of the generic Chinese valve covers for G35's off ebay. It has been a while since I have ordered (I ordered 10 sets last time), but I think they were only $60/set including gaskets.

The covers do work, but you must complete several modifications or else you will have a massive oil leak. First, the oil cap has to be sanded (it is usually not flat for some reason). We installed a set and had a massive oil leak after starting the car up; that is how we learned of this issue.

Second, there are several areas on the cover which will need additional RTV. If you compare the cover to the factory, you will see where (and why).

 

[CBR.worm]

I replaced mine with OEM valve covers, I figured it wasn't worth the risk of having to do it again. If the car is in good shape and you plan to keep it, I wouldn't skimp unless you are completely comfortable overcoming the potential drawbacks of aftermarket.

As for the plenum gasket, you need to replace the gasket between the two upper halves, I believe they tear when opening, and it is very easy to replace the (MLS?) bottom gasket as well. I used OE for everything. Or, this could be your chance to add a spacer and a thermal isolating base gasket.

 

[bowlofturtle]

Originally Posted by The Critic
We have purchased a few sets of the generic Chinese valve covers for G35's off ebay. It has been a while since I have ordered (I ordered 10 sets last time), but I think they were only $60/set including gaskets.

The covers do work, but you must complete several modifications or else you will have a massive oil leak. First, the oil cap has to be sanded (it is usually not flat for some reason). We installed a set and had a massive oil leak after starting the car up; that is how we learned of this issue.

Second, there are several areas on the cover which will need additional RTV. If you compare the cover to the factory, you will see where (and why).



But how was the original problem with leaks going into the spark plug tube?





Originally Posted by CBR.worm
I replaced mine with OEM valve covers, I figured it wasn't worth the risk of having to do it again. If the car is in good shape and you plan to keep it, I wouldn't skimp unless you are completely comfortable overcoming the potential drawbacks of aftermarket.

As for the plenum gasket, you need to replace the gasket between the two upper halves, I believe they tear when opening, and it is very easy to replace the (MLS?) bottom gasket as well. I used OE for everything. Or, this could be your chance to add a spacer and a thermal isolating base gasket.


+1 on the spacer and Iso thermal gasket. Get the 5/16 for good mid-range power gains. It is literally no additional work if you are doing VC on the VQ35. I've had a motordyne 5/16 spacer for the last 10 years and no issues.