I thought I saw a thread about this recently but haven't found it.
Anyway, I replaced the plenum plate and gasket with a hughes kit last winter (and replaced pcv with dealer one right after) yet something must've went wrong because the intake had oil in it and coolant was leaking from intake gaskets.

So replaced everything again (minus the plate) a few months ago. Took an 850 mile trip and didn't lose a drop of oil. Then a few hundred miles later I checked the oil and it was a quart low. I already knew it was the intake eating it up, but checked to confirm, and I was right.

So what now?
Is it possible the intake is warped or I got an uneven plenum plate?
Or is the intake sucking in oil thru the PCV valve for some reason?
Maybe the air in Ohio is really oily? ...idk

 

Are you 100% sure you torqued everything correctly?

I torqued the intake bolts a little extra because the actual specs just felt way too loose.

PCV valves are really finniky. Try another one although I doubt a bad one would eat a whole quart.

 

A blown headgasket? A PIA but pull the spark plugs and see if any are wet with oil(oil ring)to many things too guess..

 

Hambone, I also torqued the bolts a tad bit more. I had a wet #8 and #7 plug before I did the plenum and I just checked those plugs last week (almost a year after the fix) and they were dry. Matt, sounds like the first time you might have not cleaned the gasket surfaces of the intake and heads well enough. I had to work to clean those mating surfaces. Or maybe the gasket shifted on you when you installed. It's really hard to keep gasket in place when putting intake back on.
Do you have a baffle inside your passenger side vc? I've heard several stories of a vc without a baffle sucking a bunch of oil through your pcv. Look on the elbow of the pcv that your hose from intake connects to and see if you have oil a lot of oil in it and the tube going to intake. That might tell you something.

 

First time around a ft lbs torque wrench was used (converted in lbs to ft lbs of course) so tht may have been the problem. Second time everything was done right from what I could tell.

How would a blown head gasket allow oil into the intake?

The pcv is on the drivers side for later years just FYI. And it had the valve inside it when I installed it and I doubt it came out but I could check for the hell of it.

 

the baffle should be built into the valve cover to prevent oil splashing from valves to have a direct path to the pcv. Not sure a blown head gasket would allow oil into intake. I've read here that some people can see an oil stream on the inside of the manifold at the pcv port by removing the Throttle Body and looking down inside plenum. That would at least tell you if oil is being sucked in there by the bucket fulls. Never tried looking there for my oil leak but it would be easy enough to do! good luck. that must be really frustrating to have done the plenum twice!

 

We had a ft. lbs and inch lbs. torque wrench when we did my plenum, but the inch lb wrench is Japanese I think, couldn't figure out how to read the damn thing.

Did it the same way, converting inch lb to ft lbs, haven't had a problem with mine, did the plenum last New Years Eve.

Still have some oil loss, but I know where it's coming from.

 

Are the plenum bolts TTY, or just the intake bolts?

My Dakota was bad when I bought it (5.9, bought used with ~40k) and within 10k miles of the dealer fixing it the plenum was sucking oil again. I did the Hughes fix and didn't have a problem with it. When I pulled the heads off at over 100k it was still good.

 

Plenum bolts are standard bolts, the intake bolts are TTY.

 

I used grade 8s for the intake, lol, a year later seem to be working. I can't think of a way to get oil in the intake other than the plenum plate or the pcv....