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@Thomas Guide the first picture is correct. You see how the bottom outer ring needle is pointed to ~ -15hg at idle with the vacuum hose in the breather and the pcv still hooked up.
So why are some folks posting to block off the PCV while doing this?
Also, according to the gauge in pic 1, my motor is showing a leak somewhere quite bad, as the needle is suppose to be in the green. I can't believe my engine is leaking this badly, so either the gauge is wrong, or there's something still off in my connections?
Sorry for the billion questions on this, but you guys are teaching a man to fish here
So why are some folks posting to block off the PCV while doing this?
Also, according to the gauge in pic 1, my motor is showing a leak somewhere quite bad, as the needle is suppose to be in the green. I can't believe my engine is leaking this badly, so either the gauge is wrong, or there's something still off in my connections?
Sorry for the billion questions on this, but you guys are teaching a man to fish here
um I said to block the pcv (at the valve cover) when you put pressure IN to the motor, when you are listening for air or smoke while the engine is OFF.
While the engine is on, you need the pcv working, as that is what is making vacuum in the crankcase.
As well, that gauge is designed with its markings for reading the vacuum in an intake manifold post filter. You are not using it for its intended purpose, you are using it as a crankcase vacuum gauge. The only part that matters to you are the numbers
- is it showing vacuum not pressure, yes
- are the numbers around -12 to -15 hg, yes
- if the numbers are low like 3-8hg, I have significant crankcase leaks, no
um I said to block the pcv (at the valve cover) when you put pressure IN to the motor, when you are listening for air or smoke while the engine is OFF.
While the engine is on, you need the pcv working, as that is what is making vacuum in the crankcase.
As well, that gauge is designed with its markings for reading the vacuum in an intake manifold post filter. You are not using it for its intended purpose, you are using it as a crankcase vacuum gauge. The only part that matters to you are the numbers
- is it showing vacuum not pressure, yes
- are the numbers around -12 to -15 hg, yes
- if the numbers are low like 3-8hg, I have significant crankcase leaks, no
Ok, I'm understanding a bit more, however, according to the legend of the gauge, the bottom ring is cm and the row above is 'in', so, I'm showing -14 cm inHg ...which is -6 in inHg!!!
This can't be right.
Last edited by Thomas Guide; 02-09-2019 at 08:55 AM.
Reason: measurement corrections
psi scale goes from 0-30, hg scale goes from 0-70 as 1psi = 2.04hg
I cant see your scale legend though
Check out the pic below of the gauge I used (I actually have two of the same one, and the pressure reading at idle was the same). According to the gauge and the manual, the very bottom ring is cm-Hg, the bottom ring above it is IN-Hg and the top ring on the top portion of the gauge is PSIG (0-0.7 kg/cm2). So in fact my readings are 6 IN-Hg or 15 cm-Hg... so does this mean I have a massive leak somewhere? I would assume that I need to be in the green section of the gauge for a healthy engine.
Any takers? @Deckoz ? I have two of these gauges and they show 6 INHg, which means I got a problem, but wouldn't that mean an easily detected symptom? Still not sure I'm doing this test correctly...
I tried the propane gas trick but to no avail, no change in engine idle. Thinking of getting a smoke machine next...
To clarify if look at pic #1 of what it's reading, it appears I'm way off. Here is a closeup with an added line to help see exactly where I'm at.
I'm still of the opinion that I have no clue what I'm doing or where I'm sticking it... like a virgin, I'm measuring my crank case pressure for the very first time:
Guys, re: the gauges and what you're calling "crankcase pressure" -- are we talking about what the factory manual calls "Manifold Absolute Pressure (MAP)" or something else?
Guys, re: the gauges and what you're calling "crankcase pressure" -- are we talking about what the factory manual calls "Manifold Absolute Pressure (MAP)" or something else?
Trying to find the specs in the manual...
Oh man...to answer your questions...I don't know at this point! Earlier in this thread I was asking how crank case vacuum was measured and with what tools (as I'm also replacing all gasket and o-ring bits to solve a oil 'consumption' issue). After I asked a few different ways, in post #73 a tool was suggested to use to find this measurement that Deckoz was talking about earlier. So I purchase not one, but two of these (they are cheap and one is being returned as it's off a bit), and followed the instructions but at this stage I must plead innocent ignorance as I'm not clear on what I'm doing.
I'm trying to find if I either a) have excessive pressure (symptoms are dip stick always popping out) or b) something else, as I've just now starting consuming oil but cannot find the leak and I've done quite a bit through a process of elimination.
So I figured this new gauge will be interesting data point to help me find an answer.
I've been having issues with oil consumption on my dd 2010 Civic Si. I know the K in my car is a notorious oil burner, especially if you're using Honda oil or Mobil 1, which I do (I take it to Honda because I can't be assed with getting the car on jackstands anymore and do all the work when the oil change from Honda is 30 bucks) When I topped it off the other day my gasket was flat too, basically flat with the groove it rides in, so I couldn't imagine it sealing very well at all. Worth a shot to see if it brings my consumption levels down...if anything it'll be easier to get the cap off now as I feel I won't need to tighten it as much with a new, springy gasket.
02-09-2019, 07:58 AM
