Hello every one, I bought my truck a few months back and the guy said it had a rebuilt engine bored .04 over and pretty much new everything. And everything was working perfect ran great and all that. Exept one day in town am it started idleing super low, like about ready to die. And I took a look in the engine compartment and my weber was covered in oil, from the crankcase vent that goes to the top of the carb. Since then I've had a lot of blow by coming out of that hose and I built a mayonnaise jar catch can to catch some because it leaks out everywhere. And I have to drain that every day and a substantial amount comes out. I'm burning up oil about 1/2 qrt every few days, I only drive 12 miles a day. And my exhaust is smoking(blue) when I shift and on deceleration. Not when I floor it like rings would be. I ran a compression test 1-145 2-145 3-100 4-100. Wet test changed the compression less than 10 pounds. I have low vacuum. And new PCV/hose. I pulled the head last night an no major signs of HG leak. No crack in the head and it was not warped. And the cylinder walls look brand new! I'm running out of ideas. Any input is very appreciated!

 

Your rings are not sealing and or broke. Needs a rebuild. You can drop the oil pan, oil pickup, unbolt the connecting rods and push the pistons out.

Keep it all in order as you take it out.
Have the cylinder walls checked out.
Check the crank.

 

I had the same thing happen and was a pluged cat. May not be whats goin on with you but worth checking. good luck

 

There are many potential causes for this other than rings, although bad rings can sometimes look like this. That is the pcv (positive crankcase ventilation) valve. It sounds like you are building positive pressure in the crankcase for some reason.

X2 on checking the cat. Try removing the o2 sensor, and seeing if the back pressure relief caused by the hole this leaves relieves the issue somewhat. It will be louder than hell, but a good quick and dirty test.

Try googling or forum searching "positive crankcase pressure" for more causes. There was a user on here by the name of "bindergirl" who had a similar problem some years back, but i don't remember the root cause. She called her truck the "percolator" as a result of the oil mess it generated. A forum search on this mint turn up more info as well.

Good luck, keep us posted!

 

If its blowing that much oil by I would suspect rings. I just had the same thing happen to me 4 months ago. I replaced my pcv valve and it didn't help, finally it just got so bad I couldn't keep oil in it. I too had to use an old plastic container to catch the oil. Did a compression check and one cylinder was super low the other low but even. After that I knew it was losing way too much oil to be a pcv valve. I took the head off, dropped the oil pan and took the con rod caps off and push the pistons out to see my top rings on each piston broke. I just got it put back and rebuilt and its running like a champ with not oil blow by at all and 400 miles on the rebuild.

Also my cylinder walls had no damage either. If the rings just crack they stay in the piston ring grooves and likely won't scar the walls but they can't do their jib and let oil by, if you jeep running it however they might work themselves into the walls more. The head is the hardest part about checking the pistons, you just need to drop the oil pan and take the con rod caps off and push the pistons out. Not much more work then you already have. Might as well be sure.

 

Thanks for all the replies. I put this up a while back. I didn't have a cat. I checked everything it could be besides rings so I'm sure that's what it was. I could have rebuilt it but I've never done anything like that, my grandpa is an old motor head so he could have helped. But we just decided since he couldn't get Time off work to help I just bought a reman, and gave them my old one for a core. Kind of a shame but now I have a great running motor with lots of power! Just a little carb problems, but there always something right?

 

Cool, thanks for the update. I bought a reman in my first Toyota pickup when it died. It was a 84 with a 22r, it had a knock and I just drove it till it stopped running then also used it as a core. The new reman was a nice motor and I didn't have to worry about it, or do any work. Sometimes buying a reman is worth the price of staying out of a cold, cramped garage and getting greasy and risking doing a poor job that may not last. Congrats on the new motor. Is the carb on it a weber or the stock carb? (or a holley I guess)

 

It's a weber 38. I've tuned it several times. But I can't really figure out why it's just dumping too much fuel. Maybe it's jetted wrong? I'm going to buy a new 32/36 and a 3 core radiator to go along with the engine

 

My cousin is having his rebuilt 22r put in his truck right now and he went with the Weber 38 too. From what I have gathered that carb is a hit and miss for people. My 32/36 open one ventral at light throttle and then opens the second on higher throttle. When I open the second it takes a moment for my engine to fully get the power, I think the second is dumping too much fuel. I might need to rejet it. I think that is what makes the 38 hard for some to get right is it is basically dumping both vents all the time. I think it really needs tuned precisely more then others and you need a good air flow system and I would imagine good spark system. Probably a high output coil, wires and plugs to help combust that fuel

 

I think you're right about the 38, I've heard it needs to be tuned perfectly. It looks like a pretty old carb. So I'm just going to go ahead and order a 32/36. Seems like the better choice to me. I'm
Mostly after mpg now, power isn't too much of an issue