Vacuum line from oil filler neck?

[leakyfaucet]

This is almost a waste of a thread, but I was wondering what the purpose of the vacuum line that goes from the oil filler neck to the throttle body is? I pulled it off to check for leaks but there wasn't any vacuum on it.

I always thought it was like a 2nd PCV valve, giving the blowby gasses somewhere to go. But the hose had no suction at all.

 

[5spd GT]

As far I know the reason it is there is just to release the crankcase pressure...

A different question to it...I really don't think it matters...but I was just wondering if it is best to put the "hose" from the oil filler neck up (riding on the IAB I believe) or have it pointing down (riding on the valve covers)...I have mine pointed down towards the valve covers...and was just wondering if that little altercation means anything...or is it just pointed up to lessen the risk of oil blowing out the hose...because of gravity?

 

[HISSIN50]

yep, it is part of the PCV. remember PCV flow is bi-directional. the valve in the PCV valve does not help with this, but the hose on the filler does, while handling the situation with metered air.

5spd, interesting question. i might point mine up for the reason you said - might help a smidge with keeping oil from getting in there. then again, oil might have a hard time making it uphill from the trough if the hose rests on the cover. i would not want oil to coke in the line if the line is pointed down and rests on the cover (not sure that it could coke up in that situation anyhow).

have you thought about a fuel filter in-line on that line? i might do that (or ditch it since im SD).

 

[leakyfaucet]

I don't see how any of the oil even gets in the throttle body... it doesn't pull anything in. At least mine doesn't... maybe it's clogged?

 

[5spd GT]

5spd, interesting question. i might point mine up for the reason you said - might help a smidge with keeping oil from getting in there. then again, oil might have a hard time making it uphill from the trough if the hose rests on the cover. i would not want oil to coke in the line if the line is pointed down and rests on the cover (not sure that it could coke up in that situation anyhow).

have you thought about a fuel filter in-line on that line? i might do that (or ditch it since im SD).

Yeah I guess I didn't really think about the little bend in the hose before it begins to point down...I was just curious because I see the hose position in those two positions (IAB and on the covers) and wondered why...when I bought mine it was pointed down...I have just kept it that way?

I have noticed any oil coming out of mine (by looking at my valve covers) and I don't even have an oil baffle on my valve covers...so I'm not for sure if it would help my situation or not...so I guess a inline filter probably wouldn't do much of nothing on mine

 

[HISSIN50]

I have noticed any oil coming out of mine (by looking at my valve covers) and I don't even have an oil baffle on my valve covers...so I'm not for sure if it would help my situation or not...so I guess a inline filter probably wouldn't do much of nothing on mine

im confused. if you dont have a baffle, you are passing a bit more oil than if you did, right? if so, i might rig up a cheap catch can and filter. one can use a soup can with fittings tapped into it. paint it and it looks respectable (as i recall, Michael actually did that!). i think i might run my oil filler line off a breather again (no MAF issues) and put atleast a filter on the main valve line. maybe a catch can too.

good luck bud.

 

[5spd GT]

im confused. if you dont have a baffle, you are passing a bit more oil than if you did, right? if so, i might rig up a cheap catch can and filter. one can use a soup can with fittings tapped into it. paint it and it looks respectable (as i recall, Michael actually did that!). i think i might run my oil filler line off a breather again (no MAF issues) and put atleast a filter on the main valve line. maybe a catch can too.

good luck bud.

Yeah I technically should be passing more oil but I haven't noticed any with the baffle on or removed? I guess I don't have much "blowing" oil in that area for some reason?

Yeah Michael has a inline filter/catch can for his pcv...to help keep the oil out of his intake...I have a minor problem with that to in my intake...

It looks like here pretty soon I may need to get inline filter happy