Burning Oil

There are two types of additives to lower oil consumption. One
swells the valve seals; if you did the seal replacement right then you
can rule that out. The other kind thickens the oil to slow blow-by past
the rings. That would have been removed not long after the oil change.
You can do a simple test to see if it's worn rings: pull all the plugs
and the air filter, then run a compression test with the throttle wide
open. If you have worn rings OR valves, the compression will be low.
Then squirt about a tablespoon of higher-weight oil like SAE 80 or 90
into each cylinder and repeat the test. If the compression shoots up,
you have worn rings. It if only rises slightly or not at all it's worn
valves.

 

valves don't affect oil consumption.

 

valves don't affect oil consumption.

 

Valve seals do, however. I was assuming that worn valves would be
leaky as well, but maybe not.

 

Valve seals do, however. I was assuming that worn valves would be
leaky as well, but maybe not.

 

read the thread - they've been replaced already.

 

read the thread - they've been replaced already.

 

Did this test. No shooting of the cap at all, nor any vacuum. With my
hand on the fill hole, there was a pulsing positive pressure--chuffing
as you wrote--and oil spraying/slopping onto my hand.

I gather this is not conclusive but a crude test for seriously bad
compression, right? I expect to get an inexpensive compression tester
soon and see what this yields.

 

Did this test. No shooting of the cap at all, nor any vacuum. With my
hand on the fill hole, there was a pulsing positive pressure--chuffing
as you wrote--and oil spraying/slopping onto my hand.

I gather this is not conclusive but a crude test for seriously bad
compression, right? I expect to get an inexpensive compression tester
soon and see what this yields.

 

as it should be.

based on the above, i guess you're looking at either worn rings or the
breather system. fingers crossed on the latter.

this is not something i've tested, just suppose, but the oil consumption
in my d15 engine has dropped substantially compared to when i first got
it and after i'd fixed the leaks. my choice of oil has meant that
pretty much all of the gunk and deposits in the engine have dissolved
compared to the state it /was/ in. if this extends to the oil control
rings, which do tend to accumulate stuff like this, maybe they're free
to seal better, and thus reduce consumption? if that's true, and it is
oil rings, maybe you should stick with this engine for a while and see
what happens as your use of mobil 1 cleans things up.

 

as it should be.

based on the above, i guess you're looking at either worn rings or the
breather system. fingers crossed on the latter.

this is not something i've tested, just suppose, but the oil consumption
in my d15 engine has dropped substantially compared to when i first got
it and after i'd fixed the leaks. my choice of oil has meant that
pretty much all of the gunk and deposits in the engine have dissolved
compared to the state it /was/ in. if this extends to the oil control
rings, which do tend to accumulate stuff like this, maybe they're free
to seal better, and thus reduce consumption? if that's true, and it is
oil rings, maybe you should stick with this engine for a while and see
what happens as your use of mobil 1 cleans things up.

 

I think what Jim Beam indicated is most likely closer to the truth.
Here in Michigan one can buy a product called "CD-2 Helps Stop Oil
Burning" - available in any supermarket for $3 or so. You put a bottle
of that (if I recall, about 6 oz) with the oil change, and any oil
burning stops ..... until the next oil change. Dishonest folks who
want to dump/sell an old car with a worn engine will use this product,
and the prospective buyer will never know it unless one is really
careful about examining the car. Happened to me many years ago when I
bought my first car as an unsuspecting (and naive) student (a used 83
Civic 1300SE). The car ran fine until the first oil change ... then,
the same symptoms....
After learning from a sympathetic "Pro" as to what could have
happened, I had to start using this CD-2 stuff with every oil change,
and the car ran fine for about 40,000 miles until the blow-by became
too much to handle (and one piston blew anyway). I was using 10W-30
dyno oil (Quaker State) with CD-2 and the CD-2 did its job almost to
the very end.....

If this may be the case, you can try some of this additive and see
what happens ... you may be able to get a bunch of miles out of the
car as I did......

Good luck!

 

I think what Jim Beam indicated is most likely closer to the truth.
Here in Michigan one can buy a product called "CD-2 Helps Stop Oil
Burning" - available in any supermarket for $3 or so. You put a bottle
of that (if I recall, about 6 oz) with the oil change, and any oil
burning stops ..... until the next oil change. Dishonest folks who
want to dump/sell an old car with a worn engine will use this product,
and the prospective buyer will never know it unless one is really
careful about examining the car. Happened to me many years ago when I
bought my first car as an unsuspecting (and naive) student (a used 83
Civic 1300SE). The car ran fine until the first oil change ... then,
the same symptoms....
After learning from a sympathetic "Pro" as to what could have
happened, I had to start using this CD-2 stuff with every oil change,
and the car ran fine for about 40,000 miles until the blow-by became
too much to handle (and one piston blew anyway). I was using 10W-30
dyno oil (Quaker State) with CD-2 and the CD-2 did its job almost to
the very end.....

If this may be the case, you can try some of this additive and see
what happens ... you may be able to get a bunch of miles out of the
car as I did......

Good luck!

 

why raise it at all if the o.p. had already ruled it out? [rhetorical]
read the thread!

 

why raise it at all if the o.p. had already ruled it out? [rhetorical]
read the thread!

 

Air jetting from the oil filler cap tells you nothing, I'm afraid. Even a
brand-new engine, freshly broken in and at max oil life will exhibit
/considerable/ jetting from the oil filler cap. From oil filler neck
emissions alone, it's hard to tell the difference between the blowby of a
worn engine and a new one.

You need to have a garage perform wet and dry compression tests. Keep in
mind even these are only analogs for oil ring condition. It is possible to
have good oil rings and poor compression rings, and vice versa.

 

Air jetting from the oil filler cap tells you nothing, I'm afraid. Even a
brand-new engine, freshly broken in and at max oil life will exhibit
/considerable/ jetting from the oil filler cap. From oil filler neck
emissions alone, it's hard to tell the difference between the blowby of a
worn engine and a new one.

You need to have a garage perform wet and dry compression tests. Keep in
mind even these are only analogs for oil ring condition. It is possible to
have good oil rings and poor compression rings, and vice versa.

 

Read my reply again: "One swells the valve seals; if you did the
seal replacement right then you can rule that out." Ah, usenet...

 

Read my reply again: "One swells the valve seals; if you did the
seal replacement right then you can rule that out." Ah, usenet...

 

sorry dude, if you have two same-model engines side by side, the
difference between worn and not worn is very much apparent from that test.

only tests compression, not oil control.

indeed. see above.