What's this hole for? (Valve cover drain hole)

[crtalon]

Hi guys, I have been a silent reader for a very long
time. It is time for me to ask a question.

Background:I am in the process of heli-coiling my head. All the
studs are out, none broke in the head. The problem is that I by
mistake drilled into one of the holes too far. I know that cut into
the wall slightly because I can stick a zip-tie into the hole and it
goes down in all the way(the zip-tie is like 2x the length of the
hole) The hole is on the bottom row, the one in the middle.

I really didn't want to pull the valve cover just to see what is in
back of that wall I destroyed. I want to say that it is a hole for
a valve cover bolt, but who knows. I figured that one of you may
know. Just in case any of you are curious, yes this is my 1st heli-
coil job, yes I now have to step to all 10mm bolts, and yes I am in
the middle of a turbo install(ETE32)

Thanks a million!
Bruce

 

[2GAWD4U2NV]

I'm finalizing the last little problems I have before getting my car tuned and I noticed I had oil beginning to sit on the valve cover. I have NEVER had a problem with oil sitting on the VC. It is not the oil cap as it seal beautifully and dry.

Pulled my wires and the plugs were dry like they should be. So I was baffled as to where the oil could be from. That's when I found the hole close the the cam/timing belt.

I believe the oil is seeping from this hole. I used a small zip tie to show that the hole is completely through the VC and the zip tie also picked up oil when I stuck it through.

Can anyone explain this hole and its purpose?

 

[snowborder714]

It's normal. It's a weep/drain hole for the valve cover.
http://www.dsmtuners.com/forums/newbie-forum/175324-whats-hole-valve-cover-drain-hole.html

 

[Bud92gsx]

Have I just never looked hard enough to notice a hole..OR as that thread says, it is normal?

 

[snowborder714]

I would say it's something you just haven't paid attention to. But I can go look at every single valve cover I have at home later this week and see how "common" it is if you'd like.

 

[bryanwheat]

I've got 5 valve covers and they all have that hole in them. It shouldn't leak oil. It just goes from the middle of the valve cover to the outside. It seems to be a vent for the valley in the center of the valve cover.

 

[2GAWD4U2NV]

Have I just never looked hard enough to notice a hole..OR as that thread says, it is normal?

Lol. I was the same way. Hours after hours and I've never realized it...

That makes the leak even stranger then as my plugs and wires are bones dry as well as my oil cap. :/

 

[Bud92gsx]

If you have time..I actually would like for you to take a quick look..Cause I have never seen it before..And would really like to know how commom or miscommon...

 

[snowborder714]

Yup, I'll check out the box of valve covers I have, as well as pictures of ones I can pull up in my collection.

I'll be interested to see if my Hyundai ones have it, as I really haven't paid attention to them.


*Merging with above linked thread.

 

[Bud92gsx]

I've had a couple vc's myself and have never seen the hole in the front for sure...It would be interesting to see how many came with the holes..

 

[romeen]

Every VC I have ever seen has had the hole. OP, one possibility is a hairline crack. It's easy to crack our VC if the bolts are over torqued. These are hard to see with the naked eye. UV dye works great for this type of thing.

 

[Detective Coating]

I have easily powdercoated over 500 of these valve covers and every last one of them has had the weep hole. It is just so small that most people over look it, it is a breather hole for that side of the vc since there is no other vent on that side of the baffling. Yes oil may come out of it because your crankcase pressure is too high and it will push it out of there along with other places.