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How long does it take for oil to circulate through an engine?


JaB90
12-23-2013, 12:06 PM
This is a very general question. I realize there are many variables such as temperature, engine displacement, and type of oil.
The Scenario:
I am open to different answers but lets assume the engine I am talking about is a 4 or 6 cylinder and is an everyday car (not a Ferrari or Porsche). The car would have been sitting overnight and just started up on a 50*-60* degree (Fahrenheit) day.
How long would it take the oil to go from the oil pan to the top of the engine (and even cycle through)? (Giving a range like 30 seconds - 50 seconds, for example, is acceptable) :biggrin:

vgames33
12-23-2013, 06:01 PM
When change the oil in most cars it takes less than 10 seconds for the lifters to stop ticking. I'd imagine less than that for a car that has only been sitting overnight since the filter would already be full.

I once put a filter on without a gasket. About 3 quarts leaked out in around 30 seconds.

JaB90
12-23-2013, 07:07 PM
When change the oil in most cars it takes less than 10 seconds for the lifters to stop ticking. I'd imagine less than that for a car that has only been sitting overnight since the filter would already be full.

I once put a filter on without a gasket. About 3 quarts leaked out in around 30 seconds.

Are you referring to draining the oil for an oil change?
I was asking about oil traveling through the engine during start-up

vgames33
12-24-2013, 05:01 PM
No. When the oil is changed, the new filter is empty (they hold 0.5-1 qts depending on on size). This means that the valvetrain (generally the last item to get oil) cannot receive pressurized oil until the pump fills the filter with oil. Since the lifters quiet down within 10 seconds of the initial startup I can assume that the entire oiling circuit takes roughly 10 seconds to complete. Add a couple seconds for gravity to return oil to the sump.

The flow observed from engines that I've seen started with no filter also shows that flow volume is pretty high. I'd say .5qt/second if I had to guess. With the average sump capacity of 5qts, the circuit has to be completed rather quickly. Flow will be slower with the filter on.

JaB90
12-24-2013, 05:29 PM
That seems like a very knowledgeable response. I appreciate your response

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