New AOS same problem

[JFP in PA]

You can test the AOS by replacing the oil fill cap with a test cap hooked up to a digital manometer. Fully warmed up, you should see no more than 5 inches of water vacuum signal.

[Fiddlebog]

Originally Posted by JFP in PA

You can test the AOS by replacing the oil fill cap with a test cap hooked up to a digital manometer. Fully warmed up, you should see no more than 5 inches of water vacuum signal.

Source/link? This is news to me and I would love to check it out.

[JFP in PA]

Originally Posted by Fiddlebog

Source/link? This is news to me and I would love to check it out.

Been around for years...………….

https://www.youtube.com/watch?v=t95lNYp2plc

[flmont]

Ahh ok...But the Idle does lower when I pull the oil filler cap,..Thanks !

[JFP in PA]

Originally Posted by flmont

Ahh ok...But the Idle does lower when I pull the oil filler cap,..Thanks !

So does a marginally bad AOS. The manometer gives you a simple way to test the vacuum signal and even catches units just starting going south. We check every car going through the shop, regardless of why it is here, 5.0 or less and you are golden; over 5 and you need an AOS. Testing regime has cut back dramatically on catastrophic AOS failures.