oil in exhaust ports after rebuilt head install

[mjboehm]

I had a machine shop build me this head. I put the head back on the car started it up and noticed it was smoking really bad oil was coming out of the exhaust ports. So I replaced the vavle guide seals in the head which had 3 cuts on each valve guide seal. The car compression is 185 across the board. It has a new turbo, arp head studs with mls hd gasket. The bottom end was rebuild about 500 miles ago didn't smoke be for. Any info would be great. Here are some pictures.

 

[Rob10_99]

Looks shiny like a fresh coat of oil. I would say your MLS isn't holding up, what's it torqued to? And did you get your block nice and clean before you put the head back on?

What's the head doing off on a freshly rebuilt bottom end? Plugs look like they were burning oil?

 

[scottr126]

Oil in the exhaust ports is a common issue with the 4G63 heads. Typically due to bad seals, because either they are old, were installed incorrectly or in dual spring applications they may have caught the inner spring. Did the problem remain after you replaced the valve seals? What kind of springs do you have?

 

[mjboehm]

Well the turbo died and caused the other head to leak oil. I torqued them down to 90 ft pounds with arp molly lube, yes the head and block where nice and cleaned. Spark plugs had oil on them. The head was checked for crackes. It was decked. If the head gasket wasn't holding up would not have good compression correct? The smoke is a dark gray and smells like burning oil. It is a thick cloud.

 

[mjboehm]

Yes the problem wasn't fixed after the new guide seal install also I have stock springs.

 

[TSIfreek]

Were the valve guides replaced?? Most likely not as most heads dont get this needed step on a rebuild. If the valve guide to stem clearance is to large or out of spec (most likely it is) this will cause oil to seep down the valve stem like you have pictured.
I like to use bronze guides as you can run a tighter clearance with them and the valve job lasts longer as the valve motion stays straight thew out its motion. Valve to head seal will be better its just a win win situation with them.
Replacing the guides will require the head to have a valve job again as the seats are cut off the axis of the valve guide.
I would also get a new set of blue viton valve seals as removing the old seals will damage them.
Unfortunetly your going to have to remove the head to get the service it needs to cure your problem.
FYI you dont put copper spray on the exhaust manifold gasket as the manifold get so hot its just burned off. Use a mitsu 4 layer mls EX gasket and it will seal tight

 

[mjboehm]

The vavle guides weren't replaced. I aked the machine shop and they said they were fine.

 

[TSIfreek]

The vavle guides weren't replaced. I aked the machine shop and they said they were fine.

They all say that as they just want to get you in and out of the door. Im sure that head has over 100k on it and the guides look like hour glasses on the inside meaning the top and bottom clearance is larger than the center.
Why else would you have that much oil in the ports??

 

[mjboehm]

You make a good point. There isn't a way to test them is there.

 

[Guzman08]

nope.. they dont cost that much. you can take off your valve cover and try to look at them from there.. you dont need to take off the head to do the job but its just easier like that. i just replaced mine and oil comes out of the exhaust too. but i am thinking its my piston rings but not sure.. doesn't smoke though ..

 

[Rob10_99]

How do you replace guides with the head on, they go the other way...

 

[TSIfreek]

How do you replace guides with the head on, they go the other way...

Im sure he is refuring to the valve seals