Oil in EGR passages........

[Fastbird]

This is weird because I have the cover plate on the bottom of the manifold, and the egr is blocked off. But there's a TON of oil in my EGR passages which is believe is contributing to what little smoke I'm seeing. And I have zero clue how it's getting in there.

Flipped the manifold over to clean up the gasket surfaces and it just poured out of the two exit holes right behind the TB. I don't get it. Anyone have any idea? I'm tempted to find a way to just seal the EGR passages up since they're not getting used at this point.

[AdamG]

I had the same thing happen to me when I took my manifold off. Because it was so Light I even questioned if it was truly oil and not some type of carbon and steam. I think what is happening is that it is converted to steam and then comes in from the pvc system and then cools in that passage an turns back to oil or by product of it.

[Fastbird]

Not on my car though. I have the PCV routed to the intake tube to the turbo, and bolt valve covers run to a dedicated breather tank for each side. The PCV port is isolated from the EGR port on the LT4 manifold I have, I confirmed this today by removing the plugs from the bottom of the manifold. It's NOT coming in through the IAC ports on the runners because those are clean. I'm kind of lost here because it's enough oil to actually pour out if I stand up or flip the manifold over (notes to self, do not drive inverted until problem solved).

[Badbird_96]

Definitely no corkscrew jumps either. Maybe its a reserve tank for oil just in case you get a little low have some friends roll it over and presto it's on the full line again.

If they aren't being used and you sealed them, how would you seal them?

[Fastbird]

That's what I'm trying to figure out. I could go old school like the Acura or whatever guy who tried to polish his intake runners by dumping sand into a running motor......figure if I dump enough RTV into the thing it'll seal them up......I jest I jest. I really don't know.

One thing that perplexes me though. THe little IAC ports at the bottom of the manifold runners. Those are directly tied into the EGR passages, yet those EGR passages dump into the manifold directly behind the throttle body. Seems to me it kind of defeats the whole "isolated IAC passages" thing if they're tied into an open dump behind the tb.

[Badbird_96]

I've thought that as well. Jb weld maybe? Be cheaper than welding them shut if it would hold.

Just remember like the guy on the mustang forum. To clean your crankcase empty all oil then put a running water hose in the oil fill and start it

[Fastbird]

Yeah, could always just fire a mig into the manifold and see what happens too............

[Alex94TAGT]

Mig welding aluminum isn't particularly fun.

I can only think of a few possibilities:

1) EGR plug on the bottom of the intake manifold isn't sealing properly, or a hairline crack perhaps, which is allowing vacuum in the intake at idle to suck oil into the EGR passage from the lifter valley / PCV passage underneath the intake. If you have the intake off, seal that big EGR allen plug with an anerobic sealer (I like high-temp RED locktite).

Note that the EGR passage is entirely separate from the IAC passage:
http://i.imgur.com/gfUAJ.jpg
http://i.imgur.com/xKKnU.jpg
http://i.imgur.com/UmHmW.jpg
http://i.imgur.com/TlBpp.jpg
http://i.imgur.com/aSzU5.jpg
http://i.imgur.com/84YMq.jpg
http://i.imgur.com/AL53G.jpg
http://i.imgur.com/6pKlv.jpg

2) Weren't you having trouble with oil seepage past your valve guides? Have you inspected your valve guides / valve seals for wear? Reversion (exhaust gasses pushing back into intake manifold during overlap) could possibly sputter that oil back into the main intake plenum, to drain into the EGR ports at the front when the engine is shut off. Hypothetically. Maybe.

3) It isn't oil. Perhaps fuel or your methanol injection fluid settled down there, mixed with pre-existing oil/carbon deposits. This is perhaps the least likely -- I trust you have a pretty good idea of what oil looks like.

4) Voodoo magic.

[Fastbird]

Good Pics Alex. I know it was oil seeping past the valve guides as part of the problem, but that cleared up when I moved the turbo oil return to the back of the intake manifold where a distributor would normally be. It was an immediate difference in the smoke I was seeing when I made that one change, and another indicator is that the intake runners on the heads are absolutely spotless and clean. The rest of the inside of the intake manifold is surprisingly clean, and it's definitely oil in the EGR passages. The way everything looked I would have sworn it was all tied in together but I may have been mistake. I'm going with option 4!