#8 Cylinder on my 390 is boogin' plugs

[amdscooter]

I'm almost afraid to ask... but #8 is having issues. All 3 plugs in the photo were pulled in the last month o so. The plug on the top in the photo only I pulled on Tuesday after coming back from a local show and shine and has about 40 miles on it. All the other plugs look fine and I had the heads refreshed (hardened seats, viton seals, etc.) maybe 2500 miles ago. What are the chances I'm looking at a valve seal gone rogue vs. rings or something worse? It'll be coming apart as this is obviously not going to fix itself, I'm fishin' for advise on what I should/could be looking for when I get into it.

Thought I'd also share this photo of a nice 64 Galaxy 445FE that showed up...



 

[ScotiaFE]

Intake gasket leaking?
It's sucking in oil.

[shady]

a compression check is where I would start.

[WConley]

+1 on the intake gasket.  Print-o-Leaks?

That's a lot of oil.

[amdscooter]

Well just had the valve cover off and removed the rocker assembly. The valve seals are where they should be and everything looks normal otherwise. I'm going to borrow my buddy's leak down tester next. At this point I'm praying for a sucked intake gasket. 

[machoneman]

What make are the intake gaskets? Hopefully they are Print-o-Leaks and new gaskets will fix her up.

[amdscooter]

I used a Fel-Pro gasket set, here is a photo just prior to installing the intake...



What are the chances that one got sucked in at #8??

[ScotiaFE]

It didn't really get sucked so to speak. The angle cut at the back just above
the oil drain back is probably weeping and that is the source of the oil entry
into #8. If it was an aluminum intake then the rear bolt may have been a tad loose.
Over the years I have found that it is like a spring get the car ready thing. Put small box end on each intake bolt and give them
a snug. That is a pretty big chunk of alum, that does a lot of heating and cooling.
A small smear of goo on it will help also.

[amdscooter]

^^^ I'm really hoping you are right.

[machoneman]

Those don't appear to be the 'bad' Fel-Pros. As noted, perhaps a re-torque will help. I've noticed as well that sometimes the head gasket tabs aren't your friend! The intakes can slip a tad when plopping on that heavy FE intake and hang up the gasket.

Btw, if you do pull the intake, save the old gaskets. One can 'mike' the edges around a few good ports and compare same to the #8 port. Intake twist, misalignment, etc. could be a cause and the gaskets telegraph just how much crush, or not, they have. 

[NIsaacs]

When I see plugs like that, my experience has been a cylinder problem as the cause. Rings, piston or piston pin loosing a snap ring and gouging the cylinder wall.

Nick

[ScotiaFE]

All Nick's gloom and doom aside.
As Bob said, put a wrench on the intake bolts and snug them down and give it another try.
If it works great, if not it needed fixing anyways.

[amdscooter]

^^^ To be fair, the same thoughts Nick voiced have been running through my head as well  . There has not been any metal on the plugs I have pulled from #8 and when I pop a new plug in it runs great.... until the plug fouls. I'm hoping that if I lost a ring, landing, etc. it would run a lot worse regardless of whether there was a fresh plug in it or not. That's what I'm hoping for anyway. I'm going to put the rockers back in tonight and snug up the intake to see of any of the hardware is loose. Leakdown as soon as I have my hands on the equipment to do it.

Thanks for all your replies. 

[MustangGT]

Those plugs look exactly like the #8 plug on my old 390. Replaced the intake gaskets even though they looked decent and problem was gone

[amdscooter]

Those plugs look exactly like the #8 plug on my old 390. Replaced the intake gaskets even though they looked decent and problem was gone

^^^ That is damn encouraging news, thanks for the morale support!