whats up with a breather oil cap?
#2
The breather I believe allows the crankcase to breathe, preventing oil from getting into the intake manifold when the blower is in a vacuum state under deceleration, which pulls oil through the valve guides.
I'm not sure what the evidence is on these, whether they cure the oil issue or provide additional performance. Also you would get a lean condition if a chip isn't programmed for it.
I'm not sure what the evidence is on these, whether they cure the oil issue or provide additional performance. Also you would get a lean condition if a chip isn't programmed for it.
#4
yea, i know the theory behind it, as i work for ford, but the crankcase is already vented to the atmosphere on the drivers side valve cover, its just plumbed up to the hose in front of the throttle housing so that the air thats sucked through the crankcase is filtered through the air filter. So whats the difference?
#5
L Strikes: I think you're wrong about the driver's side cr/case air being filtered thru the air filter. The pipe/tube from the valve cover connects to the intake(rubber, ribbed part) after the air filter and after the MAF.
I added an oil breather, chip, and throttle body recently. The intake plenum(alum. piece directly on top of the s/c that the th. body bolts to) on mine was clean but the 'old' th. plates were dark brown(oil residue?) when I changed the th. body out.
Time will tell...
Dan
I added an oil breather, chip, and throttle body recently. The intake plenum(alum. piece directly on top of the s/c that the th. body bolts to) on mine was clean but the 'old' th. plates were dark brown(oil residue?) when I changed the th. body out.
Time will tell...
Dan
#6
I installed the oil breather cap about 1500 miles ago and when I took the stock airbox off for install of the 90mm kit, oil was saturated in the T/B. I checked it yesterday for curiousity reasons and it is clean as a wistle . I don't know about that whole drivers side plug thing going to the T/B boot, but I am am convinced that this thing improves crankcase ventilation.
#7
lightningrod, the way the pcv system works is, there is a vacuum line hooked to the pcv valve in the right valve cover, that sucks blowby gasses out of the crankcase, and to keep it from pulling a vacuum, fresh air is sucked in through the left side valve cover, via that tube that runs to the rubber tube right before the TB. now i surely dont think that the air its pulling through the tube comes from anywhere except through the air filter. the whole reason its behind the MAF is so that it's metered air, and since that metered air is going all the way through the crankcase and back into the intake via the pcv hose, its just the same as the air being let by the IAC valve. now the reason your chip would need to be calibrated to compensate for non-metered air to be pulled in from the pcv valve is so that the long fuel trim wont go past 20% and set a rich trim at idle. As for as the oily residue, i dont know why, but even like a 10,000 mile explorer with a SOHC motor will have oil coating the inside of the intake(boy have i disassembled quite a few of these). My thoughts are that the engine under WOT and boost has enough blowby past the rings to create a oil vapor that, since the pcv valve isnt working under this condition, would be deposited into the intake air stream. And by venting the blowby out into the atmosphere (through a vented oil cap) the oily vapor isnt going back through the intake. After thinking about it, i could see why it would be a little cleaner, but are all y'all that use the cap doing away with the tube from the TB boot to the valve cover?
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#9
NOT a problem for Emissions
Everyone,
The breather cap is NOT a problem with emissions. At least here in VA....And they do the dyno test vs idle only test.
I just had the truck emissions test done last week. All mods were left in place, including the breather cap.
Results: Passed with flying colors. 15 & 25 MPH tests were actually lower than the idle test.
I see no problems with it.....
Just my .002
The breather cap is NOT a problem with emissions. At least here in VA....And they do the dyno test vs idle only test.
I just had the truck emissions test done last week. All mods were left in place, including the breather cap.
Results: Passed with flying colors. 15 & 25 MPH tests were actually lower than the idle test.
I see no problems with it.....
Just my .002
#11
no prob. lightningrod , we were standing around talking about it this morning before work, and i guess the only reason to try to keep the oil residue out of the intake track, is to keep it from puddling and partially restricting the intercooler. All new ford engines with around 10k miles or so will look like they have a tremendous amount of residue in the intake, but thats just the way they are. I'm wondering if the oil that does puddle in the intercooler doesnt just get blown out during WOT, so at this point im not really going to worry about it i guess (especially since my truck has only 650miles on it so far, lol). The reason i started this thread with a question like this is to see if there was a point about the crankcase vent that just hadnt hit me, because i was thinking too hard about it, you know how that goes sometimes, haha.
#12
Couldn't the oil 'follow' the intake air into the combustion chamber thereby diluting the the air/fuel ratio?
Originally posted by L Strikes
no prob. lightningrod , we were standing around talking about it this morning before work, and i guess the only reason to try to keep the oil residue out of the intake track, is to keep it from puddling and partially restricting the intercooler. All new ford engines with around 10k miles or so will look like they have a tremendous amount of residue in the intake, but thats just the way they are. I'm wondering if the oil that does puddle in the intercooler doesnt just get blown out during WOT, so at this point im not really going to worry about it i guess (especially since my truck has only 650miles on it so far, lol). The reason i started this thread with a question like this is to see if there was a point about the crankcase vent that just hadnt hit me, because i was thinking too hard about it, you know how that goes sometimes, haha.
no prob. lightningrod , we were standing around talking about it this morning before work, and i guess the only reason to try to keep the oil residue out of the intake track, is to keep it from puddling and partially restricting the intercooler. All new ford engines with around 10k miles or so will look like they have a tremendous amount of residue in the intake, but thats just the way they are. I'm wondering if the oil that does puddle in the intercooler doesnt just get blown out during WOT, so at this point im not really going to worry about it i guess (especially since my truck has only 650miles on it so far, lol). The reason i started this thread with a question like this is to see if there was a point about the crankcase vent that just hadnt hit me, because i was thinking too hard about it, you know how that goes sometimes, haha.
#13