Oil gets darker = Car running rich?
06-01-2003, 09:33 AM
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Oil gets darker = Car running rich? I noticed that my engine oil gets darker as I put more miles on the car or especially after some hard driving.
Is that normal or would that mean that my car is running rich? Any other reason for that?
Is that normal or would that mean that my car is running rich? Any other reason for that?
06-01-2003, 10:13 AM
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Re: Oil gets darker = Car running rich? Simple answer, The oil gets darked as burnt combustables get past the piston rings and into the oil. The more miles you put on the oil the more contaminates get into it. The harder you drive it the more the stuff gets past the rings. It is very normal. Now as the rings ware they will let more and more get in the oil. So the older the engine is the faster it will get dark. Also things like excessive heat and coolant leaks into the bottom end, or extreme humidity will also change the oil color. Now these other things I mentioned are not normal things so if they are happening then the problem needs to be corrected asap. If you run an LS1 and have no oil cooler then you should be running synthetic oil. The LS1 and LS6 oil temp runs higher then the old 350's and the synthetic oil is recommended by GM because it can withstand the higher temps. But they too have their limitations and should not be allowed to operate out side their design limits.
06-01-2003, 05:08 PM
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Re: Oil gets darker = Car running rich? I will agree with the above post...
However I would like to add:
Oil smells like gas = running very rich
(or plug not firing, or injector stuck open)
Very unlikely in your case, but I thought it beared mentioning.
Dave
However I would like to add:
Oil smells like gas = running very rich
(or plug not firing, or injector stuck open)
Very unlikely in your case, but I thought it beared mentioning.
Dave
06-04-2003, 01:41 PM
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Re: Oil gets darker = Car running rich? Not only that, but as oil gets old it holds
increasing amounts of volatiles (from the blow-by)
which will boil back off when the engine gets
hot, and be sucked back in through the PCV. This
will make for a richer-than-planned mix especially
at idle where explicit fuel delivery and airflow
are low. This is why "they" always say to go to
smog test with a fresh oil change.
Even with a good tune, your oil will smell like
gas to some extent after it's seen enough blowby.
Until the combustion has completed there is un-
burned volatile content in the cylinder charge and
some will get past the rings.
increasing amounts of volatiles (from the blow-by)
which will boil back off when the engine gets
hot, and be sucked back in through the PCV. This
will make for a richer-than-planned mix especially
at idle where explicit fuel delivery and airflow
are low. This is why "they" always say to go to
smog test with a fresh oil change.
Even with a good tune, your oil will smell like
gas to some extent after it's seen enough blowby.
Until the combustion has completed there is un-
burned volatile content in the cylinder charge and
some will get past the rings.
