1. #1
    Join Date
    Dec 1999
    Virginia Beach VA


    Posting this for someone else:

    I have a 2.5L comanche - 1986 with the typical oil blow-by into the air box. What is the right way to fix this? It doesn't seem that rotten hoses would suddenly suck oil into the airbox?? What's the fix? Thanks.

    My 2005 Wrangler Build Thread

    “He who is without oil shall throw the first rod.” -Compressions 8.7:1

  2. 135000

    HEY-Blowby is cause by excessive wear in the cumbustion chamber. i know you dont want to hear this, but you need a ring job. Possibly to rebore the motor new pistons and rings. or find a nice 4.0L drivetrain.

  3. #3


    For your information:
    I had a similar problem with my YJ258 that might help. There are two large hoses on the valve cover, the rear one is from the cover to the air cleaner/box and the front one is from the cover to intake vacuum, with a pcv valve installed at the cover. My problem was a lot of oil was ending up in the air cleaner/box. The solution was the valve cover/pcv/vacuum hose had a small orifice inside the middle of the hose(that I couldn't see until I removed the hose) which was plugged and eliminating vacuum to unequal the pressure inside the valve cover which caused oil to blow through the rear hose into the air cleaner/box.I sprayed carb cleaner through the cleaner/pcv/vacuum hose and has NO MORE OIL! INSTANTLY! P.S. I was told I needed valve jobs to a complete engine. Sorry, all it was was !1.99 can of gumout.A year to find and a minute to fix, and that was about 60,000 miles ago!

  4. 137000

    I had a similar problem with both of the comanche pickup's I had. They both had the 4.0 Liter motor in them. I replaced the hoses mentioned above with some a little bit larger in diameter. It helped a lot but the problem really completely went away. My opinion is....either clean those hoses real good or replace them and drive the hell out of it. I treated my first Jeep truck as bad as you can possibly treat a truck and it still ran good the day I sold it and it had 185,000 miles on it. Toughest damn truck I ever seen.

  5. 1043818


  6. #6


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    What the deal with the .!?!?!?!

    Is that your way of bump or BTT -ing it? [addsig]

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