I'm about 2 do a cold air intake on my 89 xj and do away with the stock air cleaner box I have seen several diferent peoples and seen how they pluged and plumbed the vaccum and blow by lines my question is do I have 2 put a breathable oil cap on my valve cover a friend of mine said if I didn't it would blow every gasket out of the motor said that's what happened to his CHEVY inline 6 well my jeep is certianly no chevy but it concerns me I have a friend with a yj and a xj both with 94 4.0 with basically the air box removed a cone filter attached to the main line and all the lines plugged and has no problems or blew any gaskets but I know my renix is different any and all help will be greatly appreciated thanks

 

i think you will be fine just run your pcv tube down the side of the block

 

Thanks for the response I just needed 2 hear that from someone more educated about jeeps then me

 

yeah you should be fine... I don't know why your friend had that problem, that doesn't really make any sense to me. but i have the exact setup your talking about on my 89. it works fine. do it.

 

It isnt common but it happened to me also. It doesn't blow all the gaskets instantly but it did make oil leak from the rear main and valve cover. Im sure these gaskets werent in the best shape so the added pressure sped up the process. I removed the CAI and replaced the gaskets, no leaks. Could have been a fluke thing but its something to think about.

 

What all mods have u done 2 ur 4.0 dev daddy and thanks

 

Renixbeast I have yet 2 see a 4.0 that the rear main seal dosent leak lol do they make an oil filler cap with the vents in them???

 

You obviously haven't seen mine!

 

here is a pic of one for you. it wont blow out seals, just run the breather to the tube after the filter like it is stock. the build thread i took it from https://www.cherokeeforum.com/f46/built-not-bough

 

Just so you know, if your plans are to do it likethis^^^^^^^ It's not a CAI.

 

For what its worth:
https://www.cherokeeforum.com/f5/gut-air-box-86732/

Ron

 

this is true. Its not a true CAI, its a short ram intake.

 

the tube on the front of the valve cover needs to be connected to the intake tube running to the throttle body its so the vacuum the throttle body creates when off idle will relieve crank case pressure........

 

This is mine, you will have to plug the small vac line that goes into the back of the airbox for a renix

 

heres another version of renix