Hey guys,

I'm only posting because I've searched plenty of time for an answer to this question and haven't found anything definitive as of yet. Is the semi circular plug on the driver side rear of the head removable? I've been leaking oil from this area for quite sometime even though the valve cover is seated correctly and torqued to specs. If this "SCP" is leaking, is it capable of leaking a lot of oil as well. Lastly if this is removable, can I just reseal the current one or do I need to hit "Satan" for a new one?

Thanks guys

the semi circular plug you're referring to is called the 'half moon' key IIRC. yes, it is removable.

Its a small piece of aluminum that sits inside a groove. get it out by hitting the top of it on one of the sides and it will start to spin upwards on the opposite side. It's a little stubborn to 'break' loose from the sealant underneath, but it'll come eventually. Take caution when hitting it downward from one of the sides as it's aluminum and you dont wanna create leaks down the road. Use plastic, wood or something like that to hit it.

Once it's out, use a tiny bead of rtv on the groove and push it down on the groove. You can use a small piece of wood to lightly hammer it down in place on the head. RTV might squeeze out a bit, just wipe excess.

here are a couple pics with the first pic showing it missing, the next pic showing it installed.

Mike comes to the rescue! Thanks man. Going to knock this out first thing tomorrow morning.

Just a point of interest; that half moon works so good that my 4g63 buddies also use them in their heads. Seals better.

Gotcha. Definitely a good thing to know.

Originally posted by bullettdsm
Just a point of interest; that half moon works so good that my 4g63 buddies also use them in their heads. Seals better.

I have had issues with mine consistently weeping oil. Not quite sure why..

Originally posted by Ebster1085
I have had issues with mine consistently weeping oil. Not quite sure why..

Crybaby......

Haha...thanks Mark. Seriously though, mine seems to be a pain in the ass. Last time I did the valve cover I did the extra step of removing that piece, thoroughly cleaning it, and then putting it back on with a nice bead of RTV, and it still weeps a little. Really don't get it, and at this point I have decided to just deal with the small leak.

I think I fixed mine for sure. It hasn't leaked since I resealed it. I've had that leak for so long and it wasn't a little leak for me that I almost got used to it. Fingers are crossed right about now.

Not to burst your bubble, and I hope it is fixed, but when I did mine last time it didn't weak for a long time, and then started leaking again...

So I'm about a month in after resealing the half moon key and have not seen one leak from that area! Moving on to the next project.

Thanks dudes!

Good deal :thumbsup