Message text written by john & patricia donnelly
>My car seems to burn more oil than I would expect for a fresh rebuild (5K
>miles) - or about a quart every 500 miles. Going along with this thread it
>sounds like my car is similar, in that my #1 cylinder plug is accumulating
>lots of crud after only 1K miles. It's the type of crud that looks like
>carbon build-up, but the color is tan-black, not the wet black I would
>normally associate with fouled plugs. Leaving it too long without cleaning
>will cause the tip to almost disappear.
>Something different here is that my car doesn't blow any blue-ish smoke
(at
>least not what I could see). The idle is rough when cold, but the engine
>runs and idles fine when hot. I would expect this from an engine that been
>rebuilt a couple of times (ie higher compression, each cylinder is at 185
>lbs).
I did this years ago - rebuilt an engine at have it burn a quart of oil in
200 -300 miles. The car ran great and had lots of power and created very
little smoke. A co-worker of mine who spent some time at TRW working on
piston rings suggested that I had the rings in up-side-down. He said that
there is a slight twist to the rings that applies more pressure at the
bottom to help scrap the oil from the cylinder walls and if the rings are
in the wrong way oil will get under the ring and then past it increasing
oil consumption. I don't know it this is true or if he is tugging on one
of my lower limbs, but who am I to judge?
But when you consider howmany times a piston goes up and down in 500 miles
it is simply amazing that an engine doesn't use more oil than it does.
>One thing I did notice is that when I remove the oil cap the revs
increase,
>about 100 to 200 rpm. Just based on this I would suspect a bad valve guide
>as the primary cause. Another person suggested that the oil ring on #1
>didn't seat properly.
That is typical of any engine with a PCV system and not an indication of
the health of an engine unless you have a really bad case of blowby.
Good luck
Dave in St. Louis
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