James, I am not certain how the 76's are set up, but if it was a late
sixties or early 70's, I would certainly ask you to check the PCV
valve. If this valve is stuck, it would fail to suck up the blow by fumes
(than even a brand new engine has) directly to the carb. Fresh air comes
in the crank case from the oil cap which is also an air filter. The hose
that connects the air cleaner to the oil filter cap (which I suspect is
where you say your oil accumulation is seen) is designed to suck the blow
by back in the intake stream at WOT (reverse flow direction) when there is
no manifold vacuum to take it on its normal route. So, at some time or
another, there will be blowby though that tube, even on a brand new
engine. However, if the PCV is stuck, it will all flow through there. As
for the smoke you see at startup, this could be valve guide seals which are
relatively easy to replace, and they have no affect on engine
performance. If it was rings, it would smoke at all times. I am a bit
puzzled though that you don't see the smoke on a cold start. May be the
oil is cold and does not burn as quickly.
My green 68 Sedan had oil on the air cleaner ever since I got it (6-7
years, 70K miles ago). It only recently started smoking at startup, (bad
valve seals). However, when I clean the air cleaner, I notice oil
accumulation in the lowest level, but no oil in the part of the air cleaner
where the air breather cap hose connects to one of the snorkels. In fact,
for a while this hose was disconnected, and still had oil there. Further,
this engine is still very strong performer, and I leave its plugs in ther
indefinitely (I pulled a plug the other day after 30,000 miles+ of
installation, it it did not even needed to be cleaned). My theory on my
car is that when the car is turned off, gasoline evaporates from the
carb. As the car cools down, some of the heavier components of gasoline
condense (remember, gasoline is a mixture of hydrocarbons, some volatile,
and some real heavy and nasty) and accumulate on the air cleaner.
Do the following simple test. Take your oil cap off and idle the
engine. If you feel vacuum sucking from the hole you add oil (it will be
only slight vacuum, a piece of paper that sticks or not is the way to
detect this) then your PCV valve is functioning, and the blowby is not too
much. If it does not stick, check/replace the PCV. If PCV is fine, you
may have too much blow by, and a compression test is next.
D^2
At 09:19 PM 8/7/2002 -0600, you wrote:
>Hello,
>
>When I went to change the air filter in my 76 NYB this evening, I
>noticed a little pool of oil sitting in the air cleaner housing, by the
>valve cover vent. Something tells me that this is not a good thing.
>The car has been a little smoky lately, really only noticeable after
>warm starts (there really isn't much smoke at all on cold starts) and
>has been consuming more oil than usual. Is this the car's semi-polite
>way of asking for an engine rebuild? I hope not since I can't afford an
>engine rebuild right now and would have to consider selling the car.
>
>Thanks,
>James
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