blow by or bye bye

jeep90

New member
Don't know much about trans

yj with a 2.5......after running for a while i was getting smoke out of the dip stick sleeve, and when i took off the oil cap there was smoke coming out of there. the yj that i used to own did not do this, but the cj with a 4 banger did (alot more too). it is getting the usual oil in the air filter too. i guess this is just the normal jeep blow by, or is it going to need rebuilt soon? if thats the case i may not buy this yj. its a 1995 with 95000 miles.

thanks for the help
 

I'd pass on it. It already needs to be rebuilt if it is getting blow-by that excessive.
 
i thought that the blow by was a normal thing in these jeeps. every four banger that i checked out had the same problem. is there anything out there that would help, like lucas oil or something. i used lucas in my cj and it seemed to help the blow by signifigantly but that is not a permanent fix. i would be getting this jeep at a very good price, i just dont want to pass it up because of a problem that i will encounter at sometime or another with any jeep. i guess my question is.....is this a normal thing for the four cylinders? i am looking for a 4.0 and have been for a while but i just cant seem to find one, or they are way over priced.
 
I don't know if it is normal to have a little blow by. Mine has a ton, but the engine is extremely worn in mine. How bad is the blow by. On mine, everything around the air filter box is soaked in oil, but I know its not supposed to be that extreme!!
 

New Video Out

not real bad just spots on the filter, smoke coming out the dip stick sleeve when the dipstick is pulled, and the valve cover when the oil cap is off. the more i search for this topic the more normal it seems.
 
I think you're confusing the word "normal" with "common". I too have a YJ with 2.5 and it gets the typical smoke out of the oil cap. I can tell you this... I put Castrol High-Mileage motor oil in with my last oil change, and I feel like it really helped. I got a little pep back. See, I had my buddy at a machine shop do a compression check on each cylinder and my #3 cylinder is weak, meaning I'm getting blow by in that one cylinder, but not real bad. For 164K miles, it's to be expected. The rings are worn and old.

I would suggest you go to a local machine shop and have them do a compression check like I did. You can get an idea ahead of time by pulling your spark plugs and if it's oily on the spark end, then you prolly got blow by.

My machine shop buddy also said... "drive it till it blows up. No need to replace something that you could get an extra 20-40K miles out of."

$.02
C
 
I have a 110, 000 on my 94 and have no blow buy. see if you can get the rig for cheap cash cause the motor is dead, (thats what you tell them) and drop a brand new crate engine in there with the left over money. now you have a running YJ with a 36,000 mile warranty!
 

thanks for the replies, i think that im going to get it tonight. after i seen that most all four bangers have this problem and still have well over 100k miles it SHOULD have alot of life left at 95000 miles. and going from a 4.2 and driving this four cyl, the four cylinder has alot more power than the 4.2 did. maybe not torque, but there is signifigantly more hp.
 
Careful! Don't assume that because we have similar symptoms in our 2.5L, that that motor will be "okay". If that guy ragged his gas-pedal... then he might have real problems which he's passing on to you. Mileage means crap when your talking 95,000 or 195,000 on an original motor. I'd be reluctant to buy unless you're getting a great deal. A 1995 with 95K miles... i'd say no more than $4,000.

C
 

I would say that you should go for it if it's what you want. I bought my '88 from a friend, and he was always really rough on it. He was always spinning the tires and trying to make it go real fast (which Jeeps don't usually like). It now has almost 200, 000 miles and still runs alright. The cylinder walls all have huge cuts in them, which you can easily snag your fingernail on!! Most of the seels and gaskets are blown out. The blow by is so bad that the whole area under, and around, my air filter box is always soaked with oil. So in my opinion, Jeeps are tough, and a little blow by isn't bad at all. Just make sure it doesn't smoke at all.
 
Yes. For $2,000, you need to jump on that. You should've stated that in the first post, then we wouldn't have had all this discussion.

C
 

got it last night......its nice to have a jeep again :lol:
 
I need advice on the air cleaner assembly for straight six

oh yeah....when we were getting the title transfered the notary asked how much i paid, and i told her. she looked at me confused and said that it was worth 6100 private party. the kid's mom was a little upset after.
 
Not necessarily blowby, could simply be that the CCV system is not functioning properly. The CCV often becomes clogged, causing it to vent the crankcase in reverse, pushing oil into the airfilter and venting crankcase fumes through the dipstick and oilfill cap.

Check the condition of the two hoses attached to the valve cover, one in front and one in rear.

The front hose should have strong suction from the intake manifold. This hose attached to a brass boss on the valve cover. This brass boss should be removed and thoroughly cleaned, it's small orifice easily becomes clogged.

The rear hose should pull air from the airbox into the valve cover. Remove the end from the airbox and see if it's blowing or has vacuum.

You shouldn't have any blowby at 95K, that's low miles for the 2.5L and about what I have on my '95 2.5L engine.
 
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