I have a 1999 S-80 T6 with 75k miles. It can go a couple of weeks without a problem. Then if I really get on it the dip stick pushes out about an inch and I find the top of the engine covered with oil. It seems to loose about a quart and make a stinky mess. I'm guessing the PCV is plugged or restricted but don't know where to find it? Anyone else have this issue or know where the drain box is located?

 

The vent box is under the intake manifold like right behind the A/C compressor.

 

ok this is news to me, i thought the whole pcv system was tied to some box under the engine and one had to lower the subframe to get at it, what is this "vent" box under the intake ? and how can you clean it ?

 

You have to remove the intake manifold to get to the vent box.

 

so whats the other box under the engine ? and what does the vent box do ?

is this something that should be part of regular maintenance ?

 

The Vent box takes the positive crank case pressure and reroutes it back to the intake manifold and burns it.
Well I would say if it has not been done in like 100k I would do it.
It is on the front of the motor like right behind the A/C compressor.

 

Ok, that will shoot an afternoon. I assume it's like all the 4 cyl., more trouble to clean than it's worth? Any special tools or easy to break clips I should know about?

 

no special tool required.. kindof a pain the the first time but very doable. remove turbo tubing, remove fuel rail, disconnect large bolt holding banjo line to bottom of the intake (located on passengers side of intake manifold) remove intake manifold (leave throttle body attached and disconnect wiring from harness) remove serpintine belt, unbolt the air compressor and set at bottom of engine compartment, remove alternator, unbolt and remove the accessories bracket off front of motor leaving power steering pump attacheched. u are now looking directly at the oil box. its black with like 2 or 3 bolts holding it on. removal of box is self explanitory. after removing spray some carb cleaner or brake cleaner in it and slosh it all around until u feel its pretty clean OR easy solution just order a new one since u will have to order some other things anyways like a new intake manifold gasket and all the transfer tubes and seals and o-ring to reinstall the old box. mine were all goopy and yucky. also clean out any lines that connect to the oil box or at least check them for blockage.. and id also check that banjo line i mentioned earlier for blockage too as i think that has something to do with the whole pvc system stuff. i did mine in a day and to do it again i could probly do it in a couple hrs..

ive heard some people have had luck NOT removing all the accessory stuff to get the box out so u may want to try it b4 u waste ur time. the reason u need to pull it off is cause one of the bolts holding the oil box on is behind the accessory bracket.. maybe u can make or find a tool to get it out..

good luck.. oh do a search in these forums for this topic cause i know there have been a few discussions about it..