Blow-by question

That usually means you have issues with the PCV system, they are extremely touchy.

You can follow the line and as it turns to the back of the carb there is a rubber elbow there that can collapse. Then there is a solenoid thing behind there that can be replaced with a T fitting, they never worked well and the fix is a T.

Finally off this solenoid thing, there will be a tube to the charcoal canister way down under the brake reservoir. At idle pinch this like closed. If the idle changes, the canister purge valve is worn out. This will effectively shut down the PCV and cause blow by.

1/2 a quart a week is getting up there.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Daniel Paisley wrote:

you should not have to add more than 1 qt per 1000 miles looks like you exceeded this informal limit note that not all oil loss may be due to pvc- account for engine wear as well resulting in oil being combusted if this second scenario should be your concern, then note you should not lose more than 1 qt of oil between oil changes (assuming no blowby or leaks involved)

hth, pete

What Mike said. That 258 is a good ol' motor, well proven. If you've got leakage, look for a product called Tri-Seal.. good stuff, I've used it in motors, hydraulics, power steering, transmissions, all with good results. If it's burning oil, don't worry about it- it'll last about forever if you keep the oil level up and don't pick on it too hard.

John

I found when I had pcv problems, oil would come out of the engine oil dipstick....possible oil loss area, and cause other gaskets to leak. MIKE, what do you think about replacing both pcv and the one in the back with a oil breather cap?? I've changed to a webber carb and disabled all of the emissions....would that help?? Also, bill previously mentioned something about reattaching the fuel cannister as a fuel milage increase?? Any idea about the problems associated with my removing the cannister all together? Or should I reconnect it tothe webber, and if so how?? The webber instructions were crap... Thanks...you and bill are the jeep knowledge gods so far..... Robb

Well for starters today's carbs are designed to have a massive vacuum leak at their base called a PCV inlet. Without this leak, it will run really rich to the point of needed a smaller jet even.

Are you old enough to remember the old drip tubes that engines had so all the oil that pukes out goes down onto the road instead of all over the engine compartment? That is what is needed instead of a PCV valve....

The canister is also part of this system. The canister is the air vent for the gas tank. If the tank has no vent or the air filter on the bottom of the canister gets blocked with dirt, then a vacuum will form in the gas tank causing the engine to run out of gas.

I ran with the canister disconnected for a while until my wife started refusing to drive in it because of the strong raw gas smell getting into our clothes and hair.

So what flavor of Jeep and type of engine do you have?

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

"Robb S via CarKB.com" wrote: