I noticed some oil leaking from the edge of the valve covers on my 2007 350Z and need to confirm that you can not just replace the gasket alone and re-use the plastic OEM valve covers, correct? ... You have to replace the ENTIRE valve cover piece because the spark plug shaft seals are molded into these valve covers, correct? 'Just wanted to make sure before I start ordering these valve cover parts because they are rather pricey (factory oem) – My ride is a base 2007 VQ35HR

 

That's correct. Unless you want to drill out the spark plug tube seals with a hole saw and replace them with new O seals that are replaceable. There's also some new aluminum valve cover option out there, but I don't know if anyone has tried them and given any feedback on here.

You could always take the valve covers off and inspect the spark plug tube seals to see if they still look ok, but if they're original and at that point, you might as well replace. Some people will add some RTV around the seals for some extra insurance when replacing.

 

I just installed the aluminum valve covers, last weekend and they fit perfectly. This is the best option out there because the spark plug seals are replaceable and the fitment was spot on. Just like the factory covers you will need to put RTV on the front corners, I also put a drop of RTV in each corner of the cover and then inserted the gasket to keep it in place when installing the covers. The only hard part to the job was getting to the rear bolts on the valve covers. You will need a long 1/4 extension with a swivel joint to get the bottom passenger valve cover bolt. It's a huge pain to get to.

 

Thanks for the replies, guys.... jg425, did the aluminum valve covers you use to replace have any deletions of ports/holes from the original factory covers?... as far as you can tell? would you mind pointing me to the ones you got? 'Appreciate it!

 

Here ya go!

The valve covers had all the necessary holes to mount all of the brackets and harnesses, just like the factory unit. The only difference between the aluminum covers and the factory covers is that the spark plug seals are serviceable and they are secured by the plastic cover on the bottom side. Just make sure to check all of these screws and apply some blue loctite, to make sure they don't back out.

 

Here ya go!

The valve covers had all the necessary holes to mount all of the brackets and harnesses, just like the factory unit. The only difference between the aluminum covers and the factory covers is that the spark plug seals are serviceable and they are secured by the plastic cover on the bottom side. Just make sure to check all of these screws and apply some blue loctite, to make sure they don't back out. Also the PCV valve was damaged during shipping, that was the only part on the valve covers that looked suspect, so I purchased an OEM PCV valve and installed it.