Changing The Rocker Cover Gasket

[Mike_]

Rocker cover gasket change in a series 1 R33 GTS-T (RB25DET):

Disclaimer:

Do this at your own risk! I accept not responsibility for injury or damage to any part of the engine or otherwise as a result of following this guide.

For Torque specs and other specific instructions, see the bottom of this post.

What you will definitely need:

New gasket(s) from nissan

New rear cam-shaft seal(s) from nissan

Gasket goo

Large phillips-head screwdriver

Medium phillips-head screwdriver

Spanner set

Socket set

Allan key set

Around an hour - more if it's your first time.

What you don't need but should probably use:

Carby cleaner

Relatively clean rags/towels

Throttle body gasket

1. Go to Nissan and purchase the rocker cover gasket(s) you require. This guide goes through the process of replacing both.

Part numbers for RB25DET:

LEFT (exhaust side) gasket: 13270-58S01

RIGHT (inlet side) gasket: 13270-58S11

(Consult your nissan dealer to be SURE of this. I am fairly confident that I have left & right correct. I bought both for $72.05.)

'Half moon' Cam gear seals: 11051-58S00

2. Pop the bonnet.

3. Remove the crossover pipe.

There are a number of things that you must disconnect/unscrew to fully remove the crossover pipe and associated bits and pieces. These are highlighted in red on the image below.

It would be worthwhile putting a clean cloth in either end of the crossover now that it is removed, and also in the throttle body to prevent any unwanted debris entering the engine.

4. Now remove the two hoses on the rocker cover breather:

Mine split when removing as they are very stiff hoses. I will need to get new ones from Nissan and I will update this with part numbers when I do.

5. Remove the coilpack cover.

Disconnect the two connectors highlighted in red below, and then use the appropriate Allan key to remove the 8 screws holding the coilpack cover to the rocker covers (highlighted in blue)

6. Unscrew the left rocker cover

Take particular note on how tightly these screws are done up: NOT VERY TIGHTLY AT ALL. Remember not to do them up very tight when you put the cover back on. just to the point where u can see the rubber washer undergo a bit of pressure. Torque specs are at the bottom of this post.

Also, on some screws the rubber grommet will also come out with the screw, on others it will not. Do not lose these grommets!

Be very careful not to let any dirt or other crap into the engine, or into the rocker cover.

The 10 screws are highlighted on the image below (right hand side not visible)

Removing the rocker cover will now expose your camshaft:

7. Remove the old gasket from the rocker cover, and replace with the new one.

Use gasket goo or sealant on the raised half circle on the front side of the cover, highlighted below:

While I had the cover off, I cleaned the outside with Carby cleaner, being extra careful not to get any inside the cover.

Use a pair of needle-nose pliers to gently lift the old half-moon rubber from the back of the rocker assembly (highlighted in red below). Coat all outside edges of the new half-moon with gasket goo, and then reinsert it.

8. Replace the left rocker cover by replacing the screws

Remember, not too tight at all.

The process for removing the right cover is slightly different:

9. Remove the screws on the right of the cover.

Note that there is also smaller screws that need to be removed, that are currently supporting the wires:

Either that or unfold the support and remove the wires. I did it the hard way.

10. Remove the screws on the left of the cover.

Removing the screws on the left of the cover is more tricky. If you have an angled screwdriver, go for it right now! If not (I didn't) you will need to unbolt the throttle body assembly.

There are 4 bolts you need to undo. well, actually two nuts on the top, and two bolts below.

The top two nuts can be done with a spanner. Use sockets for the bottom bolts, as if you use a spanner you will need to remove the Throttle Position Sensor.

Once the TB is unbolted, unhook the throttle cable from it's position and carefully lift the TB out of the way, allowing you access to the rocker cover screw beneath.

The gasket may break in this step, so it would be handy to replace it while you are doing this. I didn't have to, but probably should have

Throttle body and throttle cable (red) and TPS (blue):

The top screw is tricky, but just involves holding a lot of stuff out of the way to get to it. Magnetic screwdrivers work well here.

11. Repeat steps 7 & 8 for this side, and then perform steps 10, 5, 4 & 3 in reverse order.

If putting the allan key screws back on the coilpack cover is proving difficult, try tightening the inner screws of both rocker covers just a little to bring them closer together.

Make sure everything that was disconnected is now properly reconnected, and all hose clamps are tight.

And you're done:

12. Start 'er up!

An abridged (but specific) guide from a workshop manual is as follows:

Hope this helps

Edited November 30, 2006 by Mike_

[RANDY]

Co-incidentally I have just done this today!

I don't see any mention of the half-moon rubbers that should really be replaced. You highlighted and said to put goo around that area, which is correct. (or goo the half-moons before you put them in).

Anyhoo, they're a seperate part number, and apparently these motors leak from there before they leak from the gasket, so while you're already there:

7. use a pair of needle-nose pliers to gently lift the old half-moon rubber from the back of the rocker assembly. Coat all outside edges of the new half-moon with gasket goo before reinserting.

Edited November 22, 2006 by RANDY

[Mike_]

I don't remember seeing any half moons aside from the raised half circle part of the gasket itself...

I'm not too familiar with mechanics in general but I know enough to get me by, so it's likely that I missed this.

Can you give me any photos of what you're referring to?

[tridentt150v]

The gasket I used had the half moons on it as part of the gasket.

[Mike_]

Ah, if thats what you're referring to then mine did too. its all one gasket, as you can see in the pics above.

[r33_racer]

the rear camshaft seals is what he means. Half moon that slips in the back half moon cutout...but by the sounds of it the new rocker cover seals have them built in now. Good idea nissan!

[RANDY]

Nope! I can see the gasket pics, and they don't have the half-moon built in. They ARE a different part number, and I had to ask for them seperately. I bought mine 2 days ago now, and they weren't built-in.

So you guys above who say you can see it built-in, that raised arch is for the front, but the rear camshaft seals (half-moon) can come out. When in, it makes the back flat, which sits flat against the flat part of the rocker gasket/cover.

I didn't take pics, but next time someone is doing this, they will be able to see what i'm talking about... as R33_racer mentions also.

So if you're still leaking oil around the back, and down onto your gearbox, those half-moons will need to be replaced and resealed! =-]

[Mike_]

Cheers for that randy, I know what you're talking about now - I will have to go to nissan and get those on my next day off. I'll update this with part numbers and instructions once done!

[RANDY]

Wicked! Nice thread in any case!

[Mike_]

Cheers

does anyone have torque specs for the throttle body and more importantly, the rocker covers themselves? I really need to get myself a workshop manual!

[justin911]

i got nothing better to do

[Mike_]

Cheers justin, you're a champ

I've edited them into the first post now

[Mike_]

First post edited with part numbers for half-moon camshaft seals and pics of replacing them

[jjman]

just about to do this job n have a query for those out there that have done it...

some of the little rubber grommets that sit under the screws around the end of the cam cover n hold it down look pretty perished on mine.

are these something that also needs to hold an oil seal and therefor need to be in good condition or what?

n if they do need to be in decent condition are they just a standard grommet or are they something im going to need to source the specific OEM part for?