It's been about 4 months since I've replaced the plenum on my 5.2 magnum and I think it's held up well for the most part. Ive took the throttle body off and looked down into the intake and it's not perfectly clean, there's oil that's blown in there from the pcv, as far as I can tell it's not puddled near the back, so Is it holding up well? And should I be able to see the edge of the gasket from inside the intake near the back?

 

I put an oil catch can on my beast. It's been in there, with a Mopar PCV, for about 5 years now. I haven't had to clean my throttle body or my IAC pintle. The Plenum is dry n clean...still. Even with a mopar PCV valve, the oil intrusion into the intake is always there. Yes, I replaced the valve stem seals already. Try it, you'll like the results!

 

I'm just trying to find the root of my engine being so weak, I feel like I gotta stomp on it just to get it to go. My exhaust is leaking at the y pipe I have in place of the cat so I think that's part of the problem, but I also think I hear a lifter tick but I don't know if that's what it is, when I rev the engine it's not smooth there's like a crackle behind it and it crackles when I let off until it idles down. When I replaced the plenum, I changed the spark plugs, cap and rotor, and spark plug wires and it ran good for about 2 days I'd say, the tone of the engine changed and I could feel a little more power, but it seems low on power again, I remember being able to hear the air suck through my 14x3 air cleaner and now I don't hear it at all so I wonder if there's a vacuum leak, Im not really sure where to start when it comes to all of the "issues"

 

What year is your truck, and how many miles are on it? What plugs did you install? Any other work done on it recently?

 

I agree with the catch can idea 100%. I used to get oil in the intake and frequent spark knock (pinging), but every time I did the vacuum test for the plenum gasket it passed. I installed a catch can a couple of years ago and haven't had any spark knock since then. The intake has never been off of my engine and it's nice and dry inside now. My only regret is that I didn't do it years ago.