My xj 4.0 is pumping oil into the air filter box. Soaking half the air filter w oil and puddling up in the intake box. What causes this. Was told the 4.0 does this a little bit but omg this isn't just a little bit of oil. It's coming from a tube from the front part of the valve cover just in front of the oil fill cap and runs into the airbox. Please help me out.

 

yes a little is normal, but it sounds like you are spitting to much. take the little tube off of the valve cover and make sure your baffle is still there.

 

I have the valve cover off to see what's going on under there and these r just gummed up w nasty deposits so I took them off to clean it

 

also make sure your back tube and connectors are not clogged either and theres vacuum on the intake port. no vacuum means it'll blow out into your air filter. i did mine a couple of months ago.

 

actually its not "normal", but its common. when I bought my XJ, there was a quart of oil in the airbox. turns out the vac line going from the valve cover to the TB was clogged, so the oil was blowing into the airbox. I got rid of that tube, put a double barb fitting in the VC, and ran some vac hose. problem solved.

 

heres a pic to show you what im talking about. its the hose going to the back of the valve cover.

 

The tube in the back is new( like 1 1/2 months ago) but the oil is coming thru this pipe. WTF is this? Lol not sure what it does. And where can u buy it. Oreilly's here don't sell it neither does autozone. They say the dealer. I'm not sure so... This thing is getting the best of me.

 

Y'all r such a huge help here.

 

WOW! Thats a clean engine bay!! Looks brand new! Mines horrible compared to that!

 

the back hose is attached to a vacuum port, see if that port is clogged and i see you cleaned out the inside of the vc. the intake sucks the fumes in from the valve cover, which in turn it sucks fresh air in the front, from the air box. if the back is clogged up somewhere itll just blow out into your airbox,oil that is. you can go to the junk yard and probably find those parts,although they might need to be cleaned up inside as well.

 

The back hose is the CCV (Crank Case Vent) hose on a 1990 some refer to it as a PCV but it is not the same as a PCV Valve, it should be a hard line like the other vacuum lines coming off of that connector by the large hose you are talking about. using a soft line will cause it to pinch from the vacuum allowing the intake to suck oil through the breather hose (the large front one) and dump it on the air filter since this is now a higer source of vacuum than the CCV is being supplied with. I was able to find a new CCV with grommet at checker for $7. it is made by Dorman part number 46005. when I pulled off the old grommet and the soft line installed by the PO and installed the new hard line the problem went away. You may have to have this part special ordered or try and find it online. do not leave the old grommet in just because it it a PITA to get out, do it correctly.

 

^^ X2

 

I ran a soft line and I have had no issues. you would have to pull ALOT of vacuum for it to collapse

 

lol thanks, it was a mess when I bought it but I stripped it down to the longblock and replace the gaskets and painted everything, pretty sure most of the paint on the block is just covering grease

 

Well it's all back together now, put in a k&n filter this time, now I'm gonna run it a few days pretty hard then check the filter and see if she has oil back in the air intake box.