Crankcase pressure results - is 5.8 bad?

[patssle]

I've been under the impression my AOS needed to be replaced. I'm burning through about 3 quarts of Mobile1 over each 5000 mile oil change interval. My AOS is 16,000 miles old and there is a slight amount of liquid oil in the tubes between the AOS in the intake. However this evening I connected a pressure gauge to my oil tube and am only pulling 5.6 - 5.8 inches at idle. I hear 5 inches is normal.

Is 5.8 inches reflective of a bad AOS?

[JFP in PA]

Originally Posted by patssle

I've been under the impression my AOS needed to be replaced. I'm burning through about 3 quarts of Mobile1 over each 5000 mile oil change interval. My AOS is 16,000 miles old and there is a slight amount of liquid oil in the tubes between the AOS in the intake. However this evening I connected a pressure gauge to my oil tube and am only pulling 5.6 - 5.8 inches at idle. I hear 5 inches is normal.

Is 5.8 inches reflective of a bad AOS?

Depends upon inches of what. You should be around five inches of water, while most vacuum gauges are in inches of mercury, where 1 inch of water equals 0.0735 inches of mercury. So if your gauge is in inches of water, you are fine; however if it is in inches of mercury, you are in trouble.

[patssle]

Yes inches of water.

[patssle]

Any thoughts to why my AOS is passing oil but pressure readings are normal? Should I replace it or not?

[healthservices]

how many miles on motor?

[JFP in PA]

Originally Posted by patssle

Any thoughts to why my AOS is passing oil but pressure readings are normal? Should I replace it or not?

The AOS will pass oil well before it totally craps out. Yes, I would replace it,

[patssle]

Originally Posted by healthservices

how many miles on motor?

About 62,000.