Redramman Posted September 3, 2008 Share Posted September 3, 2008 Hi I'm new. My Son just bought a 4cyl.5spd. 2wd 1990 Comanche .I read some other posts on this ...The rear small hose has vacuum and its grommet hole is open, the hose to air cleaner is not blocked although elbow has a crack.Oil is leaking or spraying out of valve cover and filter box. Could the baffle in valve cover be blocked ? the truck runs good .Any Ideas? Also about how many mpg do these trucks get,we could do the math but he never has enough $$ to get past 3/4 tank. Link to comment Share on other sites More sharing options...
maddzz1 Posted September 3, 2008 Share Posted September 3, 2008 On a 2wd 4 cyl I would think around 25-28 MPG. Alot of people seem to have the problem with oil in the air filter; some actually just run a catch bottle to catch the oil. I would pull the cover and clean the baffles and see if that helps. Just be careful as the valve covers on the 4cyl are plastic. Link to comment Share on other sites More sharing options...
Pete M Posted September 3, 2008 Share Posted September 3, 2008 The blowby in my 4.0 is so bad I had to install a bottle inline in the hose. This was a last-ditch effort (and was installed on the road), but works great. The tube runs in and sticks in a few inches, and then a second tube comes out but doesn't stick in as far. It traps the oil spray in the bottle and then the tube continues on to take the contaminated air to be burned in the engine like it's supposed to. Link to comment Share on other sites More sharing options...
FxRacing282 Posted September 3, 2008 Share Posted September 3, 2008 its redneck and i like it :cheers: Link to comment Share on other sites More sharing options...
The_Slow_Norris Posted September 4, 2008 Share Posted September 4, 2008 I had this problem in my old XJ. I found a right up online that said to replace the CCV valve on the back and replace the inlet fitting (on the intake manifold) with one from a 2001+ TJ. It essentially has a larger hole. And clean out the valve cover good. The result? No more blow-by, slightly cleaner emmisions reading AND no hillbilly-looking "catch" bottles. :D Now temper this with the fact my XJ had the H.O. 4.0L engine setup... I've been so busy with my CJ5 I haven't looked or compared the Renix setup on my Comanche, but it ain't got no blow by and it's up at 176K. Link to comment Share on other sites More sharing options...
ORCA Posted September 4, 2008 Share Posted September 4, 2008 I had this problem in my old XJ. I found a right up online that said to replace the CCV valve on the back and replace the inlet fitting (on the intake manifold) with one from a 2001+ TJ. It essentially has a larger hole. And clean out the valve cover good. The result? No more blow-by, slightly cleaner emmisions reading AND no hillbilly-looking "catch" bottles. :D Where's this 'right' up you speak of? I'm gonna miss my hillbilly bottle :cry: Link to comment Share on other sites More sharing options...
Redramman Posted September 5, 2008 Author Share Posted September 5, 2008 Thank you all for the info .We will be (carefully) removeing valve cover soon to check the baffles and clean it. I also wonder if the oil drain back holes in head are clear maybe we should run a small engine cleaning brush down them. The bottle oil separater idea is a good Idea I'll do that if ,or until this can be fixed. I'd also like to see that write up on the TJ hoses. I was thinking about converting to a PCV system but slightly larger hoses and fittings might work. Link to comment Share on other sites More sharing options...
wooky48 Posted September 5, 2008 Share Posted September 5, 2008 You could also make a "hot rod" out of it :brows: . After changing the broken plastic valve cover with an aluminum one I also took the hose out of the loop from the filter box by putting an Edelbrock breather (out of three it's the only one that would fit :roll: ) in the cover, no more oil in the box and the engine still gets filtered air for ccv sustem to work Link to comment Share on other sites More sharing options...
ratrapp Posted September 5, 2008 Share Posted September 5, 2008 i was also wondering about changing mine to a pcv system or something better than the old ccv system.i remember reading somewhere about how to convert to pcv but can't remember where i read it.does anybody else know where i could find this?maybe we could make this a sticky. Link to comment Share on other sites More sharing options...
wooky48 Posted September 5, 2008 Share Posted September 5, 2008 mine did have a pcv on the old cover, new one just has a hose nipple and the hole for the pipe/hose from the filter box, hose now runs from TB base to the nipple. Link to comment Share on other sites More sharing options...
Redramman Posted September 5, 2008 Author Share Posted September 5, 2008 Wooky48 Thanks! Yea I thought about that too (the breather) .I wonder if any will fit the stock 4cyl. valve cover. I should measure the hole with and with out the grommet and then check my parts catalogs. Is the tube to intake vacuum about 1/8"small inside diameter? Link to comment Share on other sites More sharing options...
wooky48 Posted September 5, 2008 Share Posted September 5, 2008 Out of 3 breathers I found the only one that fit was an Edelbrock, had to take the rubber off it and use the original, double check yours for fit, the hose I can't remember the size but 1/8th sounds right, again doublecheck what you have might be slightly different than what I have here Link to comment Share on other sites More sharing options...
Redramman Posted September 5, 2008 Author Share Posted September 5, 2008 BTW is the port at intake or TB threaded in? I wonder if going to a 1/4" vacuum hose and /or PCV would effect engine vacuume or performance? I'll try every thing else first to see if it will work with stock CCV hose. Link to comment Share on other sites More sharing options...
Redramman Posted September 5, 2008 Author Share Posted September 5, 2008 Wooky48 You have the 4cyl right? Thats what my Son's Comanche has only it's a 1990,sounds to me like the same or very simmular set up. Link to comment Share on other sites More sharing options...
Redramman Posted September 5, 2008 Author Share Posted September 5, 2008 I also need to check how much hood clearance there is above the front of valve cover. Link to comment Share on other sites More sharing options...
wooky48 Posted September 5, 2008 Share Posted September 5, 2008 yup, 89 4 cylinder, had plastic cover, got an aluminum cover from a '92 4. The TB port was the same one that went to PCV but the PO adapted somehow, another "repair" I had to fix. The setup I have now with hose to the nipple in the cover it still tuns great and decent mileage too. Link to comment Share on other sites More sharing options...
wooky48 Posted September 5, 2008 Share Posted September 5, 2008 Clearance for........?? The aluminum cover fits, no prob. Link to comment Share on other sites More sharing options...
Redramman Posted September 5, 2008 Author Share Posted September 5, 2008 Clearance for the hieght of the breather. Most breathers seem to be for 1 1/4" hole using a grommet thats 1 1/4" OD. and 3/4"Id hole ,K&N makes vent filters for 3/8,1/2,5/8,3/4,and1" holes. I also saw a 1.22" OD grommet (don't know the hole size on that one but probably is 3/4"ID). Link to comment Share on other sites More sharing options...
wooky48 Posted September 5, 2008 Share Posted September 5, 2008 I hope this works, link to my changing cover, pics are from another guys Jeep but looks like mine now 'cept for A/C and p/s, and hose on mine runs to TB base not to intake http://comancheclub.com/forums/viewtopi ... highlight= Link to comment Share on other sites More sharing options...
Redramman Posted September 5, 2008 Author Share Posted September 5, 2008 Cool! Link worked thanks for the help and Info. Bye (its way past my bed time got to get up at 4:30AM)Goodnite. Link to comment Share on other sites More sharing options...
The_Slow_Norris Posted September 6, 2008 Share Posted September 6, 2008 Here's a little interesting tibit in avoiding the hose assembly... http://74.125.95.104/search?q=cache:-Mj ... cd=6&gl=us I am still looking for the write-up involving that TJ part. Link to comment Share on other sites More sharing options...
ratrapp Posted September 6, 2008 Share Posted September 6, 2008 i think i'm going to try the pcv swap mentioned in the last post unless someone can find the tj write up. Link to comment Share on other sites More sharing options...
The_Slow_Norris Posted September 9, 2008 Share Posted September 9, 2008 Jeez... If I at least had my MJ I could take a picture of the piece and email it to you, Then I'm sure your dealer could match it up with there 2001 TJ diagram. Alas, my MJ have been in the shop for 2 weeks. :cry: I know it's the same tread pattern for the H.O. 4.0L that was in my 91 Cherokee... I'm not sure about the renix system in my 89 MJ. Link to comment Share on other sites More sharing options...
Redramman Posted September 9, 2008 Author Share Posted September 9, 2008 Did some measuring and my valve cover holes without grommet are both 1" dia..With engine running I removed front hose going to air filter and held a rag over hole,the rag pulsated sucking in an blowing out. A compression test shows #1 at 60psi, #2,#3,and#4 at 100psi .I did not retest with oil in cylinders but think its rings because compression biult up from low psi with every stroke. I might re-do test and put oil in cylinders and hook up air compressor to gage hose to listen for air leak location? Truck runs good even whith such uneven compression but this explains the slight vibration over 65mph. I wonder if rings could be just stuck? It seems like valve guids would have to be realy worn to biuld up that much preasure in valve cover so I doubt thats the problem? Thanks for the (link) info on hose recall and Napa parts. Anybody else have simular compression readings ? Link to comment Share on other sites More sharing options...
Redramman Posted September 12, 2008 Author Share Posted September 12, 2008 Finaly had a chance to work on Jeep. went to Murrays auto got a chrome breather and gromet I'll let you know if it keeps the oil from leaking everywhere. At least the air filter should'nt get soaked in oil.Still trying to figure out which motor flush or seafoam to use to try to loosten rings and clean engine . Link to comment Share on other sites More sharing options...
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