Decided to put plugs in the wife's truck yesterday.
Found oil in the first three coil pockets. (a lot) several ounces in each.

104,000 miles, clean daily driver, running great until I found this.

So I feel like it probably needs a valve cover gasket and the O-rings replaced. Got them! PCV hose was corroded and collapsed.

Do I have to take the intake off. I have the fender well out and I cant even see a bolt. What all has got to come off if I may ask? The intake looks like a plastic cover. GM should be ashamed!

I got all the tools and i'm a pretty decent mechanic so I'm not afraid of it but Daum every time I work on this thing its a PITA.

Anyway, I got to fix it. Any advice from the pros.
Thanks a million,

 

check pcv hoses, both, replace. could be the source...

oops, not a pro..

 

Man, If you have spent time under the hood on one of these things that's PRO enough for me.
I was just gonna put plugs in it and POW! oil in 3 out of 5.
The one the goes into the back left facing the motor was all gummed up. I have a new one. The other side hose looks fine.
So how would the oil get there? Is it sucking it through the valve cover gasket?

The gasket its not a problem, its the intake removal to get to the gasket I'm worried about. I cant even see a bolt head!!!

 

one hose feeds clean air to the crankcase , from there air goes to the other hose to the intake. there is an orfice in the output side and a "trap" for oil.
dont know where your problem is but try ez stuff first huh.

not a pro!

 

You are asking us where the oil is coming from, no pics provided, and you are looking at it?

The intake only has a few bolts, and they are not that difficult to get to.


BTW.... straight block modern autos/trucks have been using plastic intakes for years, they do not require the heat protection from the cylinder head valley of a V block.

 

I was asking where it came from to try and understand it because it didn't flow in from the top. It must have come through the valve cover gasket or O-rings around the coil packs Right?
I asked about the PCV hoses to understand what might have caused it to suck oil into those coil pack holes. It did not leak into the hole from the top because that hose was bad. Did it cause a vacuum?
With a normal PCV system it should not suck oil in like that right?

Its not normal to pull a coil from an engine and it be full of oil.

Thanks for all the positive feedback and help!

BTW: I personally don't drive this truck. Its my wife's. I drive diesel pickups so most everything is either Cast iron or aluminum!

 

wow, big job. ive not heard of this here since ive been here,sorry.

 

Not familiar with the H3 5 cylinder (mine's the Alpha), but every other inline engine that I've worked on could easily get oil into/around the plugs if the valve cover O-rings are bad.

 

If the breather passage (PCV) in the cam cover (valve cover) is plugged/blocked the pressure will have to escape somewhere.

Might have to remove the cam cover and clean the breather passage.

 

Was there oil inside of the plastic resonator box of the air intake or its coupler closest to the TB?