Half moon help!

[Southtwnr]

I am changing valve cover gaskets in hopes of fixing an oil leak but I cannot find the "half moon" at all. I have removed the cam plug (drivers side rear) and I feel like an idiot but I can't find it.

It's a 1999 6 cylinder

If someone can point me to a photo I would appreciate it.

Thanks

 

[Southtwnr]

Seems like it should be directly behind the cam plug but it's not......?

 

[LittleCaesar]

There are two per head, one in the front and one in the back. Find the cam that doesn't have a sprocket on it for the timing belt and you will see the half moon embedded in the head in front of and behind that cam.

Gently pull them out, clean off all old gasket and reseal.

 

[sterbenlicht]

It's beside the "hockey puck" cam bore seal. Look just beside the round black seal just an inch or two away on the cylinder head and you'll see the metal half circle sealed to the head with form in place gasket. Across the surface, it'll probably look like a very smooth section where the valve cover gasket just rides straight over like it's part of the cylinder head. It can blend in very well, but it's located directly at the end of the cam. It's there because that's how the head was machined for the cam.

 

[awpsome]

Found this picture on google, this will show you the one thats on the firewall side, i feel once you understand what they look like and find one, you should be able to match them and find them all.
One front and one rear on both sides.

 

[sterbenlicht]

That's an awesome picture. That pic looks like it's being put back together. I don't know if you're using a walk-through for this job, but just in case it doesn't mention it, first you pop it out and clean the old gasket from the surface of it and the cylinder head where it goes, put it in with fresh gasket material. Then clean the bulging material up on the valve cover mating surface away and put a little pinch of gasket material right at the joints between the surfaces as well as smearing some gasket material around the hockey pucks when you throw them in. All of this stuff should be done relatively quickly so it doesn't dry until you have the valve cover back on and tightened back down. If you don't totally seal those cam bore seals, it'll still leak. That's actually where they usually leak from in the first place anyway.

 

[Southtwnr]

Thanks guys. I am embarrassed it was so easy to find! I was presuming it was behind the cam plug. oops!

I got the vc back on and will finish up tomorrow. I am hoping this fixes an oil leak!!

 

[Southtwnr]

Pretty bummed. Looks like I will be having the rear main seal replaced:cry2:

That's too big of a job for me.

 

[LittleCaesar]

Are you 100% positive even after the VC replacement? Maybe give it a couple of days and recheck.

If indeed that is the cause of your leak, you may want to try using a high mileage oil. I had a leaking rear main seal in my Bronco and until I had the money to fix it I used Mobil Super High Mileage. It reduced the leak by about 60% until I could replace mine. If you have the money now, then get it done when you have the time.

Use only an OEM seal. Good luck.

 

[Southtwnr]

Are you 100% positive even after the VC replacement? Maybe give it a couple of days and recheck.

If indeed that is the cause of your leak, you may want to try using a high mileage oil. I had a leaking rear main seal in my Bronco and until I had the money to fix it I used Mobil Super High Mileage. It reduced the leak by about 60% until I could replace mine. If you have the money now, then get it done when you have the time.

Use only an OEM seal. Good luck.

I guess I am as sure as I can be. The leak rate seems unchanged after two days. I may try to buy some dye to be sure nothing is coming from the valve cover area.

I'm trying to look on the bright side as I changed the plugs and put it all back together without incident.

I think I'm looking at close to a grand to have the rear main seal replaced. Does that sound about right?