Found traces of oil in the intake, what's this mean?

[jkufen]

When taking off the throttle body of my parts engine I found a large amount of oil in the intake. When I took off the throttle body in the engine I am driving now there was a slight trace of oil but everything was relatively clean for a 26 year old engine. Can anyone tell me what would cause this? I am most likely not going to use the bottom end but just curious what would cause this. Cant hurt to learn something for the future. The previous owner said the engine was blown but that can mean a number of things coming from a person with no mechanical knowledge. Thanks!

 

[70roadrunner]

my neighbor had the same thing happen recently. turned out to be the PCV valve. hope this helps

 

[MPRanger]

^^x2. Change the PCV.

 

[jkufen]

Wow i thought it would have been.something more serious like a burnt valve or blown gasket but if that is all i now know the PCV valve is no good!

 

[RonD]

Yes, PCV, clean or replace, and clean the rubber hose as well.

There is also a Vent hose on most engines that runs from the valve cover(oil filler tube) to air plenum/air filter, this needs to be check and/or cleaned once in awhile.