theksmith 3,667 Posted November 22, 2020 (edited) my goal this weekend was to replace the leaky oil cooler, change the spark plugs, and replace the PCV valve. here's the parts: fully committed: what a freakin' mess! i was not able to replace the PCV valve. i could not figure out how to get my hands and a wrench in there to remove the lower screw - i'll have to pay someone for that service. however, i'm hoping one of our resident Jeep geniuses can shed some light on why my intake manifold is so full of oil (@ob1jeeper or @Curly perhaps) - could it just be from a worn seal on that weird PCV valve? note the entire intake manifold's interior was this way (all the runners), but the plugs were all dry. thanks in advance for any help on this. Edited November 22, 2020 by theksmith 2 Share this post Link to post Share on other sites
Curly 766 Posted November 22, 2020 I'm not familiar with that engine, is that the upper manifold in the 2nd pic? If so, I'd say it was the PCV. Strange that the oil seems concentrated around the seals and is not as bad in the runner. 1 1 Share this post Link to post Share on other sites
theksmith 3,667 Posted November 23, 2020 (edited) 3 hours ago, Curly said: I'm not familiar with that engine, is that the upper manifold in the 2nd pic? If so, I'd say it was the PCV. Strange that the oil seems concentrated around the seals and is not as bad in the runner. thanks Tim. that picture is the bottom of the lower intake manifold (that's the tip of the 4 hole injector you see in there). the inside of all the lower's runners are wet with oil and a thin layer of slimy gunk. the inside of the upper manifold was also wet with oil though not seemingly as "gunky" as the lower. there was even some very tacky goo (oil i guess) that had pooled at the bottom of the throttle body. this engine has a centrifugal air-oil separator attached to an end of one of the camshafts and the PCV then hugs that end of the shaft. i think that as the seal on the PCV wears, it allows oil or very oily air to leak out through the PCV, which i would expect then dumps into the upper intake manifold - but i'll have to double check the hose routing. i didn't know if there was another common reason besides a bad PCV seal or stuck-open PCV that could cause so much oil to get up into the intake. Edited November 23, 2020 by theksmith Share this post Link to post Share on other sites
4x4tographer 2,532 Posted November 23, 2020 4 hours ago, theksmith said: Wow. What do you even do in this situation? Try to soak as much up as you can with some shop towels? Looks like a lot of debris in the bottom on the photo. 1 Share this post Link to post Share on other sites
theksmith 3,667 Posted November 23, 2020 (edited) 43 minutes ago, 4x4tographer said: Wow. What do you even do in this situation? Try to soak as much up as you can with some shop towels? Looks like a lot of debris in the bottom on the photo. that valley is actually fairly deep so the first try with paper towels wasn't getting me anywhere, nor did a turkey baster. then i remembered i had this MityVac thing, which worked fairly well to suction most of it out and i cleaned up more with rags as best i could. after it was all back together i went to the car wash to spray a ton of degreaser down in there and around the back side of the engine. the underside of the trans, t-case and their skids are still kinda oily even after spraying them down for a while... maybe the dust from the next run will soak some of it up and then another good degreasing will be in order! as far as that oily pine needle type debris at the front, i didn't mess with it a ton while things were apart for fear of dropping bits in one of the many bolt, coolant, an oil holes that were exposed. hopefully the car wash sprayer dislodged some of it. Edited November 23, 2020 by theksmith 1 Share this post Link to post Share on other sites
Curly 766 Posted November 23, 2020 Again, not familiar with this engine, but a Dakota 3.x V6 I used to own had bad lower gaskets on the intake, that allowed oil to enter from the crankcase. I had to pull the upper and lower intake manifolds to access the seals. It was pulling oil out of the Crankcase into the manifold because of engine vacuum. The lower intake had what amounted to the equivalent of a oil pan seal that was defective. That may be what is happening here. 1 Share this post Link to post Share on other sites
theksmith 3,667 Posted November 23, 2020 on the funner side of things, we're an all-Jeep family once again! 1 1 Share this post Link to post Share on other sites
dzJeepChic 2,376 Posted November 23, 2020 You said 'funner', lol. Love that you guys have practically matchy-match Jeeps again! I think you should name @aimee's Jeep Zipper because she's Gadget's friend and she's little and zippy. 1 1 Share this post Link to post Share on other sites
ob1jeeper 454 Posted November 24, 2020 I'm probably late to this conversation, as yiou likely have it all back together by now... But is there any oil in the intake system upstream from the PVC ? (IE: Do you see traces of oil in the intake closer to the air filter ?... ) It appears there may be a trace of dirt/dust in the oil film that I see in the manifold runners??. Which begs the question... What airfiltering system have you installed? (sorry, did not re-read the 60-odd pages to get that background info)... Share this post Link to post Share on other sites
theksmith 3,667 Posted November 29, 2020 (edited) On 11/23/2020 at 6:00 PM, ob1jeeper said: I'm probably late to this conversation, as yiou likely have it all back together by now... But is there any oil in the intake system upstream from the PVC ? (IE: Do you see traces of oil in the intake closer to the air filter ?... ) It appears there may be a trace of dirt/dust in the oil film that I see in the manifold runners??. Which begs the question... What airfiltering system have you installed? (sorry, did not re-read the 60-odd pages to get that background info)... that dirt in the intake was from this summer when my air filter had come loose for an unknown amount of time, good eye. there's no oil in the air intake before the throttle body (where the crankcase fresh air in tube connects). rather it all seems to be coming from the PCV valve directly into the intake manifold after the throttle body. upon more research it would seem that is perfectly normal and common with this engine - even to the point of having the inside of the manifold completely coated in oil. Joe at On Point Performance & Offroad told me the 3.6L draws a high vacuum on deceleration and i guess a fair bit of oil mist makes it past the factory oil-air separator no matter what. my intake valves did not appear to have a bunch of carbon build-up (as far as i could see them when the manifold was off). also my oil level has never noticeably lowered between oil changes. all signs point to there NOT being any issue here, however i'm still going to do 4 things... try again to replace that PCV myself (in case it's stuck open or the internal seal is bad). Joe let me know to remove the battery tray to access it better. send Blackstone Labs a new oil sample for analysis. they will be able to tell if i'm getting excessive blow by (worn rings). install an inexpensive catch-can between the PCV and intake manifold so i can see just how much oil is getting back in. run a can of Mopar combustion chamber cleaner though. i've had noticeable results with it on previous vehicles, and Gadget is at nearly 110k miles already! Edited November 29, 2020 by theksmith 2 Share this post Link to post Share on other sites
