Tested my AOS today, what does this mean?
05-28-2017, 07:48 PM
#1
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Tested my AOS today, what does this mean?
I got a manometer and made a cap for testing. At idle, engine warm but not hot, the readings I got are below...showing -7.9 to -8.5. This seems to be at the higher end of OK?? Should I be concerned? Thanks in advance.
05-28-2017, 08:04 PM
#3
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Fully warmed up engine should be @ 5, retest, your AOS may be failing
05-29-2017, 01:04 AM
#6
Drifting
Mine is 5. It won't lower your reading but smear a little silicone grease on the seal of the cap to ensure you get a good seal. Calibrate the Manometer to prevent a false reading.
Check plenum for oil quickly. Once it spreads ,it gets everywhere!
Check plenum for oil quickly. Once it spreads ,it gets everywhere!
05-29-2017, 03:34 PM
#7
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Checked again today after getting the car good and hot. Reading is now 11.5-12.5 inH2O. Does this indicate my AOS is toast? I don't see any smoking at startup and the car seems to run well otherwise.
Last edited by Nickshu; 05-29-2017 at 03:53 PM.
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05-29-2017, 06:00 PM
#8
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With engine running how hard is it to get the oil fill cap off? Just as a check for your manometer. If you have 11 in water column the cap should be very difficult to remove due to the negative crankcase pressure. Also hope Jake sees this thread and gives his expert advice.
you may also want to add a tube onto other nipple or move manometer away from motor, any positive pressure, wind, air movement from motor will add additional positive pressure to that nipple giving a compromised reading. I use a manometer on a daily bases for work and they need to be calibrated.
you may also want to add a tube onto other nipple or move manometer away from motor, any positive pressure, wind, air movement from motor will add additional positive pressure to that nipple giving a compromised reading. I use a manometer on a daily bases for work and they need to be calibrated.
Last edited by texcwa; 05-29-2017 at 06:04 PM. Reason: Added info
05-29-2017, 08:01 PM
#9
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With engine running how hard is it to get the oil fill cap off? Just as a check for your manometer. If you have 11 in water column the cap should be very difficult to remove due to the negative crankcase pressure. Also hope Jake sees this thread and gives his expert advice.
you may also want to add a tube onto other nipple or move manometer away from motor, any positive pressure, wind, air movement from motor will add additional positive pressure to that nipple giving a compromised reading. I use a manometer on a daily bases for work and they need to be calibrated.
you may also want to add a tube onto other nipple or move manometer away from motor, any positive pressure, wind, air movement from motor will add additional positive pressure to that nipple giving a compromised reading. I use a manometer on a daily bases for work and they need to be calibrated.
When I remove the cap there is vacuum I have to pull against to get it off. I would not say it's difficult to remove but there is some resistance. This manometer is the $30 digital one from Amazon, I see no calibration function in the owner's manual. It does show zero with nothing connected. There is a second nipple on it that I was just leaving open, is it a flow-thru design so one is the intake?
05-29-2017, 08:25 PM
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A reading of 11.5 in of water column is ea to approx 60 psf so it should be difficult to remove with that kind of pressure. My reading of 4.8 in is equal to approx 30 psf and I could feel the negative pressure when removing.
the two nipples are not a free flow but if you hook the hose to one side it will show measurement in negative (-) the other will show positive (+). The calibration is done in a lab and the cost is more than your instrument.
you could make your own fluid manometer with a piece of clear hose (just google it) and use light weight oil (not water) just in case some gets sucked into fill tube.
the two nipples are not a free flow but if you hook the hose to one side it will show measurement in negative (-) the other will show positive (+). The calibration is done in a lab and the cost is more than your instrument.
you could make your own fluid manometer with a piece of clear hose (just google it) and use light weight oil (not water) just in case some gets sucked into fill tube.
05-29-2017, 08:44 PM
#11
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A reading of 11.5 in of water column is ea to approx 60 psf so it should be difficult to remove with that kind of pressure. My reading of 4.8 in is equal to approx 30 psf and I could feel the negative pressure when removing.
the two nipples are not a free flow but if you hook the hose to one side it will show measurement in negative (-) the other will show positive (+). The calibration is done in a lab and the cost is more than your instrument.
you could make your own fluid manometer with a piece of clear hose (just google it) and use light weight oil (not water) just in case some gets sucked into fill tube.
the two nipples are not a free flow but if you hook the hose to one side it will show measurement in negative (-) the other will show positive (+). The calibration is done in a lab and the cost is more than your instrument.
you could make your own fluid manometer with a piece of clear hose (just google it) and use light weight oil (not water) just in case some gets sucked into fill tube.
This one is inexpensive and says it can use oil....Worth a try?
http://www.dwyer-inst.com/Product/Pr...1221-1222-1223
.
05-29-2017, 08:51 PM
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Yes, that is a fluid manometer but you can just buy a length of clear hose and make your own. Google it and you will see that u just measure both sides of fluid level from the zero mark and u get a very accurate reading in inches of water.
