Oil inside Plenum?

[Mint Q45A]

Hello, When removing the plenum today, I found some oil (probably half a teaspoon) inside the plenum, right behind the TB; aroung the opening that goes to the EGR valve. Is this normal? Where is this oil coming from? Is there anything I should look for and correct?

Tks!!

[qship96]

Oil is coming from PCV system,the more worn the motor,the more oily vapor is deposited into intake to reburn.Some use whats called an oil catch can plumbed into crankcase ventilation lines to capture this oil to prevent it from entering the intake path.Why you must occasionally clean throttle body and plenum

[Infinitiguy19]

Hey I have been looking into this and If I were to use this Oil Catch Can Would I still have to clean the TB plenum and runners or would I have to do it less often?

I know that the air filter lets some crap through and over time it builds up but is this a viable option for only cleaning the TB, runners and plenum every 6 years or when ever the KS, hoses, injectors... goes bad under the plenum?

[maxnix]

It's just not time, but engine running rpm x time x volume of contaminants in air not caught by intake filter less frequency of intake fogging.

[AlabamaDan]

Blow-by!

[Infinitiguy19]

Blow-by!

what do you mean?

Do you mean the hose?

[AlabamaDan]

worn piston rings allow oil to pass (blow) by them into the combustion chamber. I'd route to a catch can.

[Q45tech]

Blow by occurs during deceleration when rings are pulled in opposite direction. Rings wear the piston groves allowing movement.

Using expensive fully synthetic oil reduces oil evaporation [of lightest fractions] and thus reduces PCV oil migration into plenum.

As the miles accumulate more and more frequent plenum cleaning is required..................at 300k+ I do a cleaning every year or 15k whereas at 100k I could get by with an every 2-3 year cleaning.

Depends on what spotless means to you.