Quick update for you all. I took the throttle body off cleaned it really well I shined my light inside the intake manifold and noticed small remnants off oil inside near the front and middle of the intake. However inside in the back of the manifold there’s a small pool of oil. Is this normal? Also I changed my pcv valve and grommet (which was cracked) a few days ago as well. Thanks!

 

I've included pictures of what I'm seeing. The first is looking straight down into the intake manifold. The second I stuck my phone down inside the intake manifold and used the flash so y'all could see the small pool of oil inside the intake manifold. Any ideas??

 

Also like I’ve said. We replaced the plenum a little over 3 years ago

 

If oil is pooling in there, either the gasket is blown, or the PCV valve has to high of a flow rate..... The gasket being bad would give you a nice vacuum leak, and account for your unstable idle.

 

This is the plenum gasket you're referring to?

 

Yep. The gasket between the aluminum manifold, and the plate on the bottom that seals it.

 

I see spots on it but no "pools of oil".
Did you use a fel pro gasket and lock tight the bolts in?

 

Okay guys here’s a quick update. We replaced the plenum gasket and all new intake manifold gaskets because there was oil inside the intake manifold. We used a healthy dose of silicone to and make sure everything was torqued to spec. Upon starting the truck it ran fun for a while but these last few days the idle has continued to fluctuate. We’ve replace the tps, iac, map sensors and o2 sensors multiple times. Any suggestions where to go from here? Could it be the evap canister, purge solenoid or speed sensor? I’m lost. Also we took the entire wiring harness out a little over three years ago and inspected everything to make sure everything was in good condition. Appreciate all the info!!!

 

Remove the pcv valve and plug the line, This will eliminat the pcv as a problem. Also there is a vac line under the left side under the throttle body that goes to the evap stuff that likes to leak. Look at the other vac lines also, The one going to the cruise actuator(under the battery) almost always is cracked or broke. If all is good it may be the iac itself.

 

Yeah, I have had troubles with aftermarket IAC motors.... unstable idle, stalling, etc. Seems they just don't react fast enough. Either that, or the 'steps' move the pintle a different distance than the Mopar units......

Probably wouldn't hurt to put a vacuum gauge on it as well. See what it's doing.