Blow-by question
 

I know that blow-by has been discussed here a number of times, and it
seems that it is quite common in the 258's. I have talked to a few
people with 258's that have the problem and offered advice that I've
read here, all the way to changing the oil fill cap. My question is
this. How much is _too_ much? I've been using Lucas Oil Treatment, and
keeping the oil changed often. I've never had a vehicle with a blow-by
problem, and it kinda makes me nervous. So, is there a point when there
is too much blow-by, and if so, how much is it? I add _maybe_ 1/2 qt. a
week driving roughly 300 miles a week. 89 YJ, almost 120K. TIA, Dan

Re: 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:
>
> I know that blow-by has been discussed here a number of times, and it
> seems that it is quite common in the 258's. I have talked to a few
> people with 258's that have the problem and offered advice that I've
> read here, all the way to changing the oil fill cap. My question is
> this. How much is _too_ much? I've been using Lucas Oil Treatment, and
> keeping the oil changed often. I've never had a vehicle with a blow-by
> problem, and it kinda makes me nervous. So, is there a point when there
> is too much blow-by, and if so, how much is it? I add _maybe_ 1/2 qt. a
> week driving roughly 300 miles a week. 89 YJ, almost 120K. TIA, Dan

Re: 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:
>
> I know that blow-by has been discussed here a number of times, and it
> seems that it is quite common in the 258's. I have talked to a few
> people with 258's that have the problem and offered advice that I've
> read here, all the way to changing the oil fill cap. My question is
> this. How much is _too_ much? I've been using Lucas Oil Treatment, and
> keeping the oil changed often. I've never had a vehicle with a blow-by
> problem, and it kinda makes me nervous. So, is there a point when there
> is too much blow-by, and if so, how much is it? I add _maybe_ 1/2 qt. a
> week driving roughly 300 miles a week. 89 YJ, almost 120K. TIA, Dan

Re: 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:
>
> I know that blow-by has been discussed here a number of times, and it
> seems that it is quite common in the 258's. I have talked to a few
> people with 258's that have the problem and offered advice that I've
> read here, all the way to changing the oil fill cap. My question is
> this. How much is _too_ much? I've been using Lucas Oil Treatment, and
> keeping the oil changed often. I've never had a vehicle with a blow-by
> problem, and it kinda makes me nervous. So, is there a point when there
> is too much blow-by, and if so, how much is it? I add _maybe_ 1/2 qt. a
> week driving roughly 300 miles a week. 89 YJ, almost 120K. TIA, Dan

Re: Blow-by question
 

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

"Daniel Paisley" <dmpazlee@webtv.net> wrote in message
news:20097-4245A2F2-555@storefull-3118.bay.webtv.net...
> I know that blow-by has been discussed here a number of times, and it
> seems that it is quite common in the 258's. I have talked to a few
> people with 258's that have the problem and offered advice that I've
> read here, all the way to changing the oil fill cap. My question is
> this. How much is _too_ much? I've been using Lucas Oil Treatment, and
> keeping the oil changed often. I've never had a vehicle with a blow-by
> problem, and it kinda makes me nervous. So, is there a point when there
> is too much blow-by, and if so, how much is it? I add _maybe_ 1/2 qt. a
> week driving roughly 300 miles a week. 89 YJ, almost 120K. TIA, Dan
>

Re: Blow-by question
 

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

"Daniel Paisley" <dmpazlee@webtv.net> wrote in message
news:20097-4245A2F2-555@storefull-3118.bay.webtv.net...
> I know that blow-by has been discussed here a number of times, and it
> seems that it is quite common in the 258's. I have talked to a few
> people with 258's that have the problem and offered advice that I've
> read here, all the way to changing the oil fill cap. My question is
> this. How much is _too_ much? I've been using Lucas Oil Treatment, and
> keeping the oil changed often. I've never had a vehicle with a blow-by
> problem, and it kinda makes me nervous. So, is there a point when there
> is too much blow-by, and if so, how much is it? I add _maybe_ 1/2 qt. a
> week driving roughly 300 miles a week. 89 YJ, almost 120K. TIA, Dan
>

Re: Blow-by question
 

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

"Daniel Paisley" <dmpazlee@webtv.net> wrote in message
news:20097-4245A2F2-555@storefull-3118.bay.webtv.net...
> I know that blow-by has been discussed here a number of times, and it
> seems that it is quite common in the 258's. I have talked to a few
> people with 258's that have the problem and offered advice that I've
> read here, all the way to changing the oil fill cap. My question is
> this. How much is _too_ much? I've been using Lucas Oil Treatment, and
> keeping the oil changed often. I've never had a vehicle with a blow-by
> problem, and it kinda makes me nervous. So, is there a point when there
> is too much blow-by, and if so, how much is it? I add _maybe_ 1/2 qt. a
> week driving roughly 300 miles a week. 89 YJ, almost 120K. TIA, Dan
>

Re: Blow-by question
 

Mike Romain wrote:
> 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

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

Re: Blow-by question
 

Mike Romain wrote:
> 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

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

Re: Blow-by question
 

Mike Romain wrote:
> 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

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