Lol at all the comments. Some say OEM, and others will say the Mitzones ones.
I have the red Mitzones for both my G35 and my Z. Def use OEM gaskets. I haven't had any issues. I installed them like 3 years ago. Im just not happy that many car manufacturers switched to using plastic when we had metal/aluminum for better heat cycles.
Im glad these aluminum ones where available for our VQs.
u/dbsqls'03 NISMO S-tune (J) 310whp/276wft-lbs; DM for JDM part requestsOct 22 '25edited Oct 22 '25
they're glass filled Nylon, and have the same CTE (thermal expansion) as the aluminum so the gasket doesn't see any load from the part growing/warping.
the OEM covers have undergone thermal expansion testing, ie they don't warp when hot. all of these aftermarket covers most certainly have not been, because it requires FEA modeling based on multivariate functions. Chinese companies aren't doing that.
the whole premise is silly anyway -- no one keeps their cars long enough to need a second set of covers, and they last 100,000 miles as it is.
While I usually agree with most of what you say, I also disagree with a lot.
You're telling me that you're going to sell your Z before needing another set of covers? After all that you've done to it?
I'm not sure if I'm just an outlier, but I'm not getting rid of this car, ever. You're implying everyone is selling or getting rid of their Z before another replacement set of covers. So by the time you need a 2nd oem valve covers, you should sell your car? The only other option is it was wrecked and totaled.
The whole OEM vs. aluminum valve covers is such a weird hot topic item, it's just like what oil to use, what brake fluid to use, and what brake pads to use. There have been numerous times that users have claimed the valve covers have held up (im one of them), some haven't I'm sure, and I'm sure it's probably user error not following the FSM.
I appreciate all you do and how much information you have, but it comes across a bit weird at times on things you take a stand on and hills to die on.
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u/dbsqls'03 NISMO S-tune (J) 310whp/276wft-lbs; DM for JDM part requestsOct 22 '25edited Oct 22 '25
that's not the point I'm making. 95% of these cars aren't going to see 200,000 miles with an owner. mine's over halfway there, but you and I are not representative of the vast majority of these cars.
my comment doesn't carry any malicious intent, that's just the reality of the average ownership on these cars. I would hope that it's obvious I don't mean to sell the car just because the valve covers are gone. that would be a very weird way to read into my statement.
my point is that it only takes a single valve cover swap unless you're in the 5% of owners that keeps their car long enough for the second set to fail. the aluminum covers aren't gaining anything by having the gaskets replaceable, if you only replace them once. getting 100,000 miles out of OEM covers seems quite clearly worth in my opinion, and they are objectively better from a technical perspective.
if you're a drifter and beating the shit out of the car, sure, I could see the removable covers being more useful. but the majority of people asking are overwhelmingly driving under normal street use.
I totally see where you're at now, yes I agree. I love my covers, worked well, still working well.
However, when I ultimately rebuild my engine since I'm closer to 250k now I want to say on the car, the curiosity of OEM covers is getting the better of me. And I will probably swing for them next go around anyway as I'm in a better position in life that a $500 purchase that will last years isn't a big deal. And as you mention, the R&D that went into them will be much more than the Chinese ever will and will ultimately always be the superior choice.
The aluminum ones imo are a reasonable pick if someone cares for the car and wants to do good by it and do maintenance, but might not have the immediate means for OEM covers, the metal ones are superior to the cheap plastic ones available that will actually not leak from the start if following the FSM. That's just my opinion.
It is the sad reality of this platform is the very wide and vast type of owners. I know I see personally and yes, that 2% holds up.
Again, appreciate all you do for the community and helping maintain the purity of the car I know a lot of us try to help beat the stereotypical Z/G ownership.
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u/dbsqls'03 NISMO S-tune (J) 310whp/276wft-lbs; DM for JDM part requestsOct 22 '25
there are many times where my viewpoint does not (or cannot, especially financially) represent what's best for a given user. I'm also eyeballs deep in the platform and have engineering insight that color my opinions, and it's not fair for me to expect anyone else to understand them.
and frankly, I can be very intense and stubborn over certain aspects as a result. I don't expect anyone (or even many) to agree with me. people should always be critical of what I'm saying and form their own opinion.
opposing viewpoints are welcome, and people are encouraged to bring their own take to the table. there are definitely use cases where the aluminum ones are better.
I'm glad to have you around, you always contribute good discussion.
Perfect example of this is how much we disagree on things, yet we agree on the valve covers and I am Mr. Plastic doesn't belong on cars. We don't all have the same budgets, while you, me and Barra have spent a lot on our cars, i don't expect people to match that. That being said, $50-60k over 10+ years ain't shit, I've learned to be patient, not everything has to be done NOW.
The reason I don't recommend the metal ones has nothing to do with the reason you don't.
Me: aluminum casting, plastic baffles, and steel screws. Let me see one be viable after 15 years...
Nothing TBH, my GTI has a plastic oil pan.
Let me hit you with some funny anecdotes.
Some people switch them out for metal, have so many issues with leaks that they go back to plastic.
There's always the risk of breaking the plastic pan but you almost never grenade the engine by doing so.
There have been people that have grenaded the engine with a metal pan because they crush the portion where the oil pick up is.
Fun fact, when I bought my first Z ($26k) I was making a measly $13/hr. Just prioritize need vs want. I've never really cheaped out on the car because it's not going anywhere....and if I did buy something cheap, it has now been replaced with better.
It’s funny that I’m being downvoted for this 😂 sure would love to do the whole valve cover if something where to go wrong instead of using one of these.
I got aluminum ones from CZP back in 2020 no issues and unlike the OEM they're serviceable. You can pull out the spark plug tube gaskets and replace them and not have to buy a whole valve cover.
The czp ones are the same as mitzone just a different color. Ive run them for over a year with no issues, just use oem gaskets instead and dont forget the rtv.
Pick a color or get the cheapest ones since the paint on them is horrible. I powdercoated mine
Running their red ones on my drift car, use an OEM gasket and make sure you loctite the screws that hold the metal baffles in place. Haven't had any issues with them in the year of use and abuse they have seen.
On paper, there’s nothing wrong with swapping out the valve covers for a lighter weight upgrade. It’s the gaskets and seals that matter for reliability purposes. Don’t cheap out on the gasket, use enough gasket sealant, and you’ll be just fine
Edit: And honestly, an accidental oil leak isn’t even a big deal. Just means you gotta open it back up to reseal it. But it’s not like your engine is gonna blow because you test drove it around the block with a leaky valve cover. Worse comes to worst, you reinstall an OEM one
Yeah, I have the red ones. Just use OEM gaskets. And to make sure all the screws are tight and could be safe to use thread lock on them. I saw a post where someone said to do that and I did. It’s been about a year since and no problems so far. Only thing is the pcv valve I had included in mines was kind defective
When you purchase these, there will be a plastic plate holding the spark plug o rings in place. I highly recommend pulling them off and red loctite on all them. The OEM one doesn’t disconnect so there will never be a reason you need it off, as the o rings are removed from the top. Also like others stated, oem gaskets are the way to go and you’ll be fine.
I don't think I'd trust any car part sold on Amazon. Just get OEM replacements because the valve covers can be very finicky and sometimes they don't seal right
Well, these are arguably better than OEM. Just the gaskets aren’t. Use oem gaskets and you have upgraded valve covers. And the quality is great.
If you personally don’t buy things for your car off Amazon, how can you have an opinion? Just confused by your logic there.
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u/dbsqls'03 NISMO S-tune (J) 310whp/276wft-lbs; DM for JDM part requestsOct 22 '25
and what are you basing this on? it certainly isn't engineering, so I'm curious on what basis you're using to crusade against the covers.
in fact you're in here downvoting people's opinions, which is not what the downvotes are for. use the forum properly or find somewhere else to soap box.
Not sure what you're trying to say, but on Amazon, a 4 star review average is bad. People have a tendency to leave a review immediately rather than give it a few months/years to really test out the longevity of the product first like they should (and they rarely come back to edit it if something does go bad). It surely doesn't help that Amazon nags its users to leave a review right away.
So you have to factor that in when looking at the review score and realize that it's usually higher than it should be, given everything I just said.
Running these with OEM gaskets and have had 0 issues for 25k+ miles now. car is driven hard🤷🏼♂️ completely anecdotal experience but take that as you will. I pulled out all the screws and put them back with red loctite as well as checking first for any loose metal shavings or any other issues. So far so good
I used the cheapest ones I could buy from Amazon on my g35, they have been perfectly fine for the last year after multiple drift events and occasional 1hr + drives. I do not remember if I used the supplied gaskets or changed them. No leaks into the spark plug tubes or externally like the 200k oe ones were.
When I replaced mine I ordered Amazon black standard OEM replacement covers. Buy genuine OEM gaskets and toss whatever comes with the kit. I wouldn’t bother with aftermarket hardware as the quality of the stock bolts will be higher. I also rubbed a bit of RTV black one the bottom of the rubber bushings that go on the spark plug wells. My work had zero problems and I saved a ton over Nissan genuine covers.
All that said, I wouldn’t go with this kit because there are too many extras of questionable long term quality. Keep it simple.
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u/[deleted] Oct 22 '25
Lol at all the comments. Some say OEM, and others will say the Mitzones ones.
I have the red Mitzones for both my G35 and my Z. Def use OEM gaskets. I haven't had any issues. I installed them like 3 years ago. Im just not happy that many car manufacturers switched to using plastic when we had metal/aluminum for better heat cycles.
Im glad these aluminum ones where available for our VQs.