1998 yukon, is my intake manifold really bad at all?

[exp500]

^^^^^Dist also has flat gasket on base at attaching flange.^^^^^^
If gasket broken, then a very small leak. Normally a small seep if anything.
Take it to carwash , leave engine running. Don't spray dist. Then on way home buy a few cans of brakekleen and a small stainless or brass toothbrush. I think your leak was oil sender or valve covers. Have to remove starter and lower cover on trans to see rear main. Same there, clean and run a few minutes then inspect.
Inspecting each item after cleaning and a shortrun should show. PITA but works.

 

[Eman85]

Wash everything down and dry it. You need a inspection mirror and a good flashlight. Oil will run downhill like other things and there is nothing pressurized that can leak aside from the sending unit which you say you've resealed. The intake gaskets are notorious to leak coolant out of the corners where they meet the heads. The only place the intake would leak oil is where the intake seals to the china walls with RTV sealer, usually not a problem unless someone worked on it. Distribtor does have a gasket under it but not common to leak. Spray powder like foot spray can help trace the oil trail.

 

[OR VietVet]

Wash everything down and dry it. You need a inspection mirror and a good flashlight. Oil will run downhill like other things and there is nothing pressurized that can leak aside from the sending unit which you say you've resealed. The intake gaskets are notorious to leak coolant out of the corners where they meet the heads. The only place the intake would leak oil is where the intake seals to the china walls with RTV sealer, usually not a problem unless someone worked on it. Distribtor does have a gasket under it but not common to leak. Spray powder like foot spray can help trace the oil trail.

How does that powder foot spray work? Interesting.

 

[wjburken]

How does that powder foot spray work? Interesting.

I imagine it acts as an aid in seeing where oil is leaking as it provides a nice contrast so you can see the dark oil that is absorbed by the white powder.

Similar to using penetrant die and developer in looking for cracks.

 

[OilBurner2003]

Is an o-ring on the shaft of the distributor

Thank you! I will look at that. It would make a lot of sense.

 

[OilBurner2003]

I imagine it acts as an aid in seeing where oil is leaking as it provides a nice contrast so you can see the dark oil that is absorbed by the white powder.

Similar to using penetrant die and developer in looking for cracks.
View attachment 379008

Wow, that's interesting. What brand of powder is this?

 

[wjburken]

Wow, that's interesting. What brand of powder is this?

What I posted was a photo of dye penetrant used in non-destructive testing. It’s made by Magnaflux, a prior employer of mine.

I would think, like @Eman85 said, some talc or gold bond powder might do the trick. I think they even have gold bond in a aerosol form that might work.

 

[east302]

You mentioned the oil pan - is there oil at the balancer (front crank seal or front oil pan lip) being blown back by the fan? There’s just not much on the middle/forward end of the passenger side other than the valve cover. Is there oil on the head at the exhaust manifold? Spitballing, could that one stain be an exhaust leak? Spark plug threads on that side are dry?

Is the front china wall seam on the intake dry?

I like the powder ideas. Going to have remember that (unfortunately).

 

[Eman85]

The powder trick was actually from a GM tech bulletin back before cell phones. You can use regular baby powder if you can dust it in the area but spray foot powder or something similar works. It will show the trail of oil. You can also buy fluorescent dye and add it to the oil and use a blacklight just like what's used to detect AC leaks.