TEF1701

I'm looking for someone who is really good at reading spark plugs. I've attached a couple of pics. All plugs look like this except #4, which looked perfectly normal. The plugs are NGK. I'm pretty sure I know what would cause the crud on the plug, but I thought I would get some outside opinions.

Rogviler

I would say it's almost certainly oil, due to the cleaner tips and shiny appearance. When it's a rich condition the black is very dull, soft, and even fuzzy. It will often cover the tip, as if you spray-painted the plug. Due to the nature of CIS it's less likely that a rich condition would show on only some of the plugs as well.

It's likely that it's coming through the PCV hose into the intake, so I wouldn't necessarily start worrying about worn rings and all that yet. See if you can confirm the presence of oil in the intake first.

-Rog

TEF1701

Is the PCV valve the giant valve on top of the intake boot? I'm only asking because they are usually small and grommeted directed in to the intake manifold.

Rogviler

As far as I know, none of them had a PCV valve. It should just go straight into the intake, with a fork going into the hose that connects the idle stabilizer valve to the intake boot.

I bet a catch can would solve the problem.

-Rog

TEF1701

Thanks Rog. I think I know what hose you are talking about. Is it the rubber one that comes off of the lower driver's side of the engine, that then goes into a metal pipe, which then goes into the intake boot? I think I may even have a catch can somewhere among my many hot rod parts. I'll have to look and see.

There is definitely oily crap just inside the mouth of the throttle body. I never really gave much thought to the oil that gets sucked in to the intake. I wonder how much better our cars would run if the EPA never got involved. Of course we would then be driving boats instead of cars because of global warming causing the ice to melt which kills the polar bears and causes the oceans to rise... sorry I was rambling