if you read the instructions, it says nothing about removing the throttle body, so the answer is no.

I did read the instructions, but in another thread, the guy did remove it:

http://g35driver.com/forums/faq-diy/...t-job-diy.html

removing the throttle body is not necessary

thanks!

Do you know how big the opening for the driver's side crankcase port is (at the rear of the valve cover)? Any pics of that by chance?

Sorry to open up an old thread, but I'm getting ready to replace my valve covers tomorrow. The service manual mentions putting RTV on the edges of the camshaft bracket. Anyone have any insight into this? The picture isn't clear in the service manual. Thanks.

Attachment 424396

For future references.

Gonna give this a shot soon...thanks for this. Nissan quoted 500 bucks for this service. Are there any performance gaskets out there other than the ones sold at oreilly/pepboys/autozone?

i did mine a couple of months ago everything seemed fine and parked the car for about 3 months,now the passenger side is leaking from the back so i bought a new gasket and plan on replacing it before a fire starts from hitting the header...had a pinched gasket....recommend putting rtv on gasket to hold in place flip valve cover let it sit for like 30 min then install valve cover...I kept having problems where the gasket kept coming off when I was installing it.

Gonna do it a third time tonight...had to buy new valve covers because theyre both leaking into the spark plug wells. At least I know how to do it from beginning to end so it shouldnt be too long.

Same issue here one of my spark plugs was flooded by oil, were did you order the covers from? And for time wise I got down to the valve covers in less than an hour, so maybe two hours tops for the complete install.

Thanks for your DIY, OP. I have a couple of refinements to offer:

Instead of loosening the coolant tube under the throttle body first, you can initially unclamp that hose above the driver's side manifold and empty the manifold/throttle body passages first at the side of the engine. You can catch the coolant more easily there, and not a drop of coolant will be released when you then free the manifold from that hose at the manifold.

The other thing I recommend instead of covering the intake with a towel is to cut a narrow piece of cardboard to cover the intake ports - and use the manifold nuts to hold it in place.

I'm doing this project now, because I was smelling hot oil in my cabin at times, and the underside of the car is completely dry. I did see oil/soot in the vicinity of my dipstick port though, so I'm hoping I'm not doing this for nothing (though when I removed the manifold, I can see slight oil seepage (it's wet) on the inner edge of the driver's side valve cover - but not enough to drip into the engine valley at all (it's dry down there). I cannot see any overt leaks outside of the valve covers - and I'm about to pull the plugs to see if the plug ports are wet.

There was also a tiny bit of oil around the manifold bolts corresponding to cylinders #4 and #6, and a tiny bit in the intake channels underneath that 6 bolt cover under the manifold.

I have 185k on my Z, and it gets 26.5mpg on the original plugs and runs flawlessly - though every once in a great while it stumbles/idles roughly for a brief moment upon startup. I gotta believe I'll at least get a performance boost by changing plugs. Anyone have ideas of other things I should tweak (intake spacer?) while I'm in here?

If you've a DE engine, the 5/16th spacer is a big improvement.

thanks for the suggestion!

I don't see any leaks - at least on the driver's side - so far. The plug tubes and plugs are completely dry. The plugs - OEM NGK - have worn electrodes, but they're in amazing shape for having 185k miles on them: brown, dry, and the sign of a healthy engine.

I wonder if changing the spark plugs jostles the plug tunnel seals and actually creates the leaks. :icon43:

We'll see. I'm doing the passenger side tomorrow. Anyone have any other ideas where a semi-slight hot/burning oil smell would come from if not from the valve covers? I can see that the dipstick tube must not have been properly seated a while back (there's oily grime in the vicinity and along the edge of the valve cover - but not on the exhaust manifold cover). It doesn't look like enough to have caused a smell.

It's not coming out of my tailpipe; it's not at the bottom of the engine or anywhere else I look.

I'm stumped. I'm cleaning up as I go; hopefully that eliminates the smell I picked up. I'll do a search for 5/16" spacer to see about putting that in.

Yeah, keep checking around, that can help, also check for leaks in the manifold/before the cats.

Chances are, when you remove the plenum top, you'll see all the oil that's sucking through the PCV system. You can't go wrong with the Motordyne 5/16th spacer.

Ok - here is no question that the plug seals for #5 - and #3 a bit also - have failed. The plug socket was full of oil after fishing down to extract the plugs. The plugs themselves look as good as the rest of them, though.

I'm going to try something that was alluded to by another poster. The way these seals are designed (stupidly - it seems to me that the best design for this centered plug tube would have been to create a sealing lip for each tube ON THE COIL ITSELF, so that when the coil is bolted down, it seals off the top of that tube, completely cutting off any chance of oil running down that tube from the bad seals on the valve covers), there is a small gap between the metal plug tubes, the valve cover body, and the seals in that cover. I vacuumed out the oil in that space, and then dried it out using paper towel dipped in carb cleaner. I used Permatex non-hardening gasket maker, and forced it into that ring gap - filling the space - and then I ran my finger around the edge to seal and make a smooth transition.

I cannot see how this wouldn't work - but if it doesn't, I don't see any harm that it could do either.

Will I get an oil smell at times because the plugs are getting wet on the OUTSIDE of the plugs? I don't see any other leaks, and I don't want to remove the valve covers to fix something that ain't broke.

I never saw any leaks - and I did see a bit of oil when I removed the plenum top, but not much (which I suppose is good).

Thanks!

You will get the hot oil smell once enough oil is outside the engine and it has gotten hot enough to give off fumes.

You won't see too much in the plenum due to the design, it has a baffle plate that covers the intake from the PCV valve, i can't remember if you can remove that, but if you take off the pipe on the front of the lower plenum, you will have oil there.


A side note here, i just took mine off that connection after a few thousand miles after fitting a catch can, and there isn't even oil vapour in there! :)

I could probably do a catch can at some point, but it isnt urgent for me. I just don't have much if any oil under that baffle plate (which I took off: it's connected with 6 bolts).

Now I'm chasing down my next problem while I have it all taken apart: my AC stopped working last year in an instant cloud of steam which I'm assuming was all my refrigerant escaping when something burst. I don't know much about AC systems, but with a failure that instant and catastrophic, some component failed, and I have to find it. I think I'll have to find fittings for the AC hi/low ports so I can pressurize the system with air and listen for the hissing.