Idle RPM and Oil Pressure

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Tim H
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Idle RPM and Oil Pressure

Post by Tim H »

Trying to find the proper idle RPM setting for my Lycoming DA40.

I've searched the forum and seen numbers ranging from 600-800. Mine idles around 800 which "feels" low, but I am told the idle setting is too high.

The other issue I have with lowering the idle is the oil pressure (even at 800) is in the yellow.

Just wondering what idle settings others are seeing / using and if they see low oil pressure (yellow range) at those settings.

Thanks!!
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TomO
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Re: Idle RPM and Oil Pressure

Post by TomO »

According to Lycoming, between 600-650 idle speed is recommended. My plane idles at 650 to 680 rpm and is happy.
The low oil pressure light normally comes on at that level. Lycoming recommends 1000 rpm for ground operations.
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Rick
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Re: Idle RPM and Oil Pressure

Post by Rick »

The AMM says idle speed should be 740 plus or minus 20 RPM.

Edit: Sorry, Tom - we posted at the same time. Where did you see 600-650?
Roanoke, VA (KROA)
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TomO
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Re: Idle RPM and Oil Pressure

Post by TomO »

My info was found in the Lycoming Tech Tips on page 18. This was found on line issued by Lycoming. This has been what my mechanic has been using.I am always open for different inputs or suggests if he wrong.
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Rick
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Re: Idle RPM and Oil Pressure

Post by Rick »

And Diamond says 720-760 in the AMM, so I guess that is why people are getting the more general "600-800" idea! In reality, I don't think the exact number matters that much, as long as it runs smoothly and isn't TOO high.
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